Chapter 1 Seeking for a sustainable way of living
- current progress of the project -


Recently the word "sustainable" has often been used. It is used in this home page with a meaning of pursuing a happy human life for as long as the sun exists, relying on its energy. The decision to undertake this project was made on New Year's Day of 1990 as a New Year’s resolution. When I was involved in measuring public nuisances, especially noise pollution, the problems were of a local nature. Now problems are global. I could not understand why society was unconcerned and did not pay much attention to these issues. I started to think that we have to find practical methods and find them right now. In the beginning, the plan was to finish the project in ten years. The project is not yet completed and I want to report on the past 15 year’s work of our sure realization of sustainable living. However, the things I still want to do are increasing and I can not handle all of them by myself. Frankly speaking, I need others help with the project.

At this age of mine I am interested in the world after death more than anything. What kind of world is waiting for me? There is an inexpressible anxiety, however this is not fear but interest in where I go, because I believe that it is a space continuous from the present world. The discussion of this question has taken place in the past since ancient times and will continue for enormous time. God gives us a great energy source in the sun, the warm embrace of the earth and the universe to help solve the question. Because it is not known when we will find the solution to this ancient question, we need to keep our precious earth safe in order to be able to think through the solution. In such a way I define the word "sustainable" broadly. Therefore, we need to recognize that solar energy is the only reliable energy source and is sufficient to supply all the energy that we use. It is estimated that the sun gives us 15,000 times the energy that all human beings use. In other words, we can keep living as long as the sun exists and we co-operate to solve the last subject given by God.
Each individual should think by himself, with his own creation in mind, about the philosophy that has usually been created by great religions, and try to meld them to find his individual solution to this subject. In such a way, instead of being persuaded to believe any particular philosophy, one has to think deeply based on one’s individual creation. This should compose a fundamental tenet of individualism, which is never selfish.

The latest point at which the earth will perish is when solar energy ends. At this moment any creature on the earth will die. Where will our souls go then? There will need to be a new start towards finding a new world for human beings. Not wandering in the universe, we need to establish a firm destiny and purpose. This will be the preparation for a new start.The thought that everything turns to nothingness at the end of the earth is the same process as bacteria or fungi finishing their lives after they consume all the energy of organic food. A human being must have a more superior existence or else we can not have any real joy and meaning in life.
It is said that joy is an impulse from the gods. It is obtained only on earth through a self which will not exist in the next world. Romance, arts, music, literature, science all come through ourselves. Therefore, we have to have as many joys as possible, enhance our spirit, our mind, our thought and make a new start in the next plane. However, these joys are accepted and allowed only when sustainable lives are established.
Some of the following items are technological, however most of them are common sense. Accordingly, in defining sustainability clearly, I want to further a wider discussion.

Another point I wish to emphasize is that most technologies of the past relied on and were developed by using easily obtainable energy, leaving much environmental pollution and contamination. When fossil energy is used up (it is said that this will be within the next 40 years), most of these technologies will not be useful any more. We will have to go back some years and start to establish new sciences in order to realize a sustainable life whereby we rely on solar energy. We need to go back in time and make changes at the point where we find the forgotten and take a new direction. As I will point out later, when we aim at having sustainable lives we notice there are a lot of hidden scientific regions to be developed around us. I am originally an Acoustician who has been involved in Architectural Environmental Engineering in a Department of Architecture. Otherwise, I am a common person. Though my shallow scientific knowledge may bring scornful laughs, I want to emphasize on this homepage that there is a new direction towards which we should co-operate.

If you look at it from a practical point of view, one should work for oneself not for anybody else. If one works to a certain degree, nature will help one a lot. Finally an individual becomes free, independent and liberated from external powers, and can establish oneself. This life-style brings a dramatic change, but it is not a revolution because this word evokes a power struggle. A sustainable life is not one for power struggles, but for self reform. To live sustainably is to physically find a living way until the sun finishes its life. For that, we have to live modestly, using natural energy, not contaminating the earth, living self-sufficiently through organic farming. These things are essential. A social structure must be constructed with a low hierarchal structure which is based on the spirit of social service. As a result, there will naturally not be wars for greed or power struggles.
Using a further broader definition, if a human being as an individual establishes a sustainable life in nature, he can make his or her own creative life. His creation will live successively in the next plane and should be developed in the form of spiritual activity to find continuity. Then, even when the sun dies, we will be able to proceed to the next plane.


The environment has indeed become bad. We know that there have been many extinctions of creatures, the greenhouse effect, unusual climate changes, the land has been filled full of poisonous substances and so on. A man who clearly predicted the present situation 150 years ago was American Indian chief, Seattle. He replied to the then American President in 1854, when he was asked by the president to sell his tribe's land.

"This earth is precious"

How can you buy or sell the sky, the warmth of the land? The idea is strange to us
If we do not own the freshness of the air and the sparkle of the water, how can you buy them?

Every part of the earth is sacred to my people.
Every shinning pine needle, every sandy shore, every mist in the dark woods, every clearing and humming insect is holy in the memory and experience of my people. The sap which courses through the trees carries the memories of the red man.
The white man's dead forget the country of their birth when they go to walk among the stars. Our dead never forget this beautiful earth, for it is the mother of the red man.
We are a part of the earth and it is a part of us.
The perfumed flowers are our sisters; the deer, the horse, the great eagle, these are our brothers.
The rocky crests, the juices in the meadows, the body heat of the pony, and man - all belong to the same family.

So, when the Great Chief in Washington sends word that he wishes to buy our land, he asks much of us. The Great Chief sends word he will reserve us a place so that we can live comfortably to ourselves.
He will be our father and we will be his children. So we will consider his offer to buy our land.
But it will not be easy. For this land is sacred to us.
This shining water that moves in the streams and rivers is not just water but the blood of our ancestors.
If we sell you land, you must remember that it is sacred, and you must teach your children that it is sacred and that each ghostly reflection in the clear water of the lakes tells of events and memories in the life of my people.
The water's murmur is the voice of my father's father.

The rivers are our brothers, they quench our thirst. The rivers carry our canoes, and feed our children. If we sell you our land, you must remember, and teach your children, that the rivers are our brothers, and yours, and you must henceforth give the rivers the kindness you would give any brother.
We know that the white man does not understand our ways. One portion of land is the same to him as the next, for he is a stranger who comes in the night and takes from the land whatever he needs.
The earth is not his brother, but his enemy, and when he has conquered it he moves on.
He leaves his father's graves behind, and he does not care. He kidnaps the earth from his children, and he does not care.
His father's grave and his children's birthright are forgotten. He treats his mother, the earth, and his brother, the sky, as things to be bought, plundered, sold like sheep or bright beads.
His appetite will devour the earth and leave behind only a desert.
I don't know. Our ways are different from your ways.
The sight of your cities pains the eyes of the red man. But perhaps it is because the red man is a savage and does not understand.
There is no quiet place in the white man's cities. No place to hear the unfurling of leaves in spring, or the rustle of an insect's wings.
But perhaps it is because I am a savage and do not understand.
The clatter only seems to insult the ears. and what is there to life if a man can not hear the lonely cry of the whip-poor-will or the arguments of the frogs around a pond at night? I am a red man and do not understand.
The Indian prefers the soft sound of the wind darting over the face of a pond, and the smell of the wind itself, cleaned by a midday rain, or scented with the pinion pine.

The air is precious to the red man, for all things share the same breath - the beast, the tree, the man, they all share the same breath.
The white man does not seem to notice the air he breathes. Like a man dying for many days he is numb to the stench.
But if we sell you our land, you must remember that the air is precious to us, that the air shares its spirit with all the life it supports. The wind that gave our grandfather his first breath also receives his last sigh.
And if we sell you our land, you must keep it apart and sacred, as a place where even the white man can go to taste the wind that is sweetened by the meadow's flowers.

So we will consider your offer to buy our land. If we decide to accept, I will make one condition. The white man must treat the beasts of this land as his brothers.
I am a savage and I do not understand any other way.
I have seen a thousand rotting buffaloes on the prairie, left by the white man who shot them from a passing train.
I am a savage and I do not understand how the smoking iron horse can be more important than the buffalo that we kill only to stay alive.
What is man without beasts? If all the beasts were gone, man would die from a great loneliness of spirit.
For whatever happens to the beasts, soon happens to man. All things are connected.

You must teach your children that the ground beneath their feet is the ashes of your grandfathers. So that they will respect the land, tell your children that the earth is rich with the lives of our kin.
Teach your children what we have taught our children that the earth is our mother.
Whatever befalls the earth, befalls the sons of the earth, if men spit upon the ground, they spit upon themselves.
This we know; the earth does not belong to man, man belongs to the earth. This we know.
All things are connected like the blood which unites one family. All things are connected.
Whatever befalls the earth befalls the sons of the earth. Man did not weave the web of life; he is merely a strand in it. Whatever he does to the web, he does to himself.
Even the white man, whose God walks and talks with him as friend to friend, cannot be exempt from the common destiny.
We may be brothers after all.
One thing we know, which the white man may one day discover - our God is the same God.
You may think now that you own Him as you wish to own our land, but you cannot. He is the God of man, and His compassion is equal for the red man and the white.
The earth is precious to Him, and to harm the earth is to heap contempt on its Creator.
The whites too shall pass, perhaps sooner than all other tribes. Contaminate your bed, and you will one night suffocate in your own waste.
But in your perishing you will shine brightly, fired by the strength of the God who brought you to this land, and for some special purpose gave you dominion over this land and over the red man.
That destiny is a mystery to us, for we do not understand when the buffalo are slaughtered, the wild horses are tamed, the secret corners of the forest heavy with scent of many man, and the view of the ripe hills blotted by talking wires.
Where is the thicket?Gone.
Where is the eagle?Gone.
The end of living and the beginning of survival.

Already in his time he foresaw the present state we live in, and he finished his letter saying, "It is the end of living and the beginning of survival."Look at our daily attitudes in the way we carefully avoid foods with additives, the way we put water filters on water from the main civic supply. We have to make a lot of effort just to survive. Chief Seattle was quite right. When I resigned from Kansai University at age 60, I made my students read his letter in class. I also said to them that there soon might come such a time that we will have to live with a bottle of mineral water in our hand and a cylinder of fresh air on our back.

It is strange. Surviving early childhood by eating hardly any food (including the stalks of sweet potatoes), experiencing rapid economical growth and living at the zenith of the materialistic world, why do I miss my early days? The smell of grass in the field where I chased dragonflies and grasshoppers, the clear sea water where I enjoyed fishing and swimming, not only Chief Seattle but also I feel very nostalgic, missing the time when life was full of nature. Nature's persuasion is great. When a new large building was constructed on my campus, I expected the surrounding trees to grow faster. It is a similar feeling to Seattle’s.
When I was younger it was normal to use a fan or if lucky, an electrical fan in summer and to heat in winter by using a 'hibachi' (a personal heater) and by wearing thick clothes. On a summer night after taking part in 'bon-odori' dancing we enjoyed eating a cool watermelon which was kept in the well, and jumped into a 'futon' bed shaking the mosquito screen in order to sleep soundly in the night coolness, shaking off the fatigue from the hot summer daytime.This brings warm memories back to me. All these things are gone now and we do not know who, where and how they were taken away.
Chief Seattle criticized materialistic attitudes and technologies, and predicted modern nuisances and global contamination. His foresight is profound and wonderful. It was apprehension against greed and technology given by a person who lived with nature. Can the solutions to protecting our precious earth only come from people who have touch points with nature and feel it closely?

Now, how has Architecture in Japan has contributed to society? High-rise buildings and skyscrapers look gorgeous at a glance, but how about houses for people? The author has travelled to a lot of countries, but has never seen such poor houses as in Japan. Cheap construction, poor design and so on. Electrical equipment and air-conditioning systems make them look rich, but they have no greenery and their indoor spaces are very poor. When fossil energy is finished, they will change into slums. In high-rise buildings, which are created by "new construction materials", huge amounts of energy have to be used for the air-conditioning system, lifts and so on, from when it is first designed. When fossil energy is finished, they will be turned into ruins. Japan is not a wide country. However, the Japanese are packed into 4% of their land and look to cheap conveniences for results. Every building uses similar "new building materials". If it is cheap and has appealing points, it conquers the market. Even if it is hazardous and not friendly to nature, they start to use it from North to South.

There was a small international conference on "Earth building" at Auckland University in November 1990. At the meeting were people who respect nature - enthusiasts or even fanatics of sun dried clay brick, adobe and earth building. One of the main subjects was nature-friendly building materials. It was reported that new building materials can badly affect our health. Damage to adobe buildings by earthquakes was reported from Ecuador, Turkey, and New Zealand etc.
I was going to give a lecture on architectural environmental planning, but was asked to do one on Japanese earth buildings which meant a quick study. I talked about how cobbed walls over a 'komai' bamboo net stood well against many earthquakes, as shown in Japan’s history, and how the thermal insulation of double cobbed walls with an air space in between and good heat capacity can give us wonderful building materials. I also talked about the thatched roofs commonly used from tropical to cold regions. We should review through scientific analysis traditional vernacular materials and methods of construction - and not only of walls and roofs.

It is necessary to "find" what nature-friendly materials are. "find" was a theme given by the editorial board of the Architectural Institute of Japan. My comment was published on Vol.106, No.1313, 1991(May). It is reproduced here with a minor change.
It is clear that in Osaka city the yearly average temperature is closely correlated with energy consumption. Exhausted heat and stored heat in concrete structures create a heat island. When we took a subway ride during my childhood in summer, we expected to be able to travel to a cool place. What is the situation now? Many air-conditioners are operated at full strength at subway stations. This is one piece of evidence. I don't know the proportion ofenergy used for factories, trains, cars, air planes and households, but the household sector must use not a small amount. Now, Architectural Environmental Engineering has a great role in this region.

It is advantageous that three dimensional solutions for a sound field, thermal conditions and a light field are practically obtained. These physical estimations should be used for Architectural planning through an estimation function to predict the indoor environment. We have proposed a method to synthesize these heterogeneous environmental factors, giving a common subjective scale of 'uncomfortableness'. Details of this are given in chapter 5. From the quantification there, a thermal environment, especially in summer, is the dominant factor of them. Therefore, we started to look at the question of whether it is possible to have not uncomfortable thermal conditions without disturbing the natural environment. Namely, the hotter outside, the cooler inside in summer and the colder outside, the warmer inside in winter. Here, what we are to "find" is to be able to realize this for an indoor environment using ground heat.

It is known that there is a level that steadily maintains the average air temperature on the surface about 8 meters below the surface, if the earth has usual thermal conduction factors. If we could take it up, it is cooler in summer and warmer in winter. We plan to create buoyancy or lifting power with the solar energy in the solar room without using any fossil energy. It is difficult to dig 8 meters deep but 4 meters is practical and possible, laying cool tubes there and guiding the outside air through into the basement. In winter, this energy will be collected like windmill electricity, solar energy, compost fermentation heat and so on, and can be added to ground heat. We can have a temperature of 26 degrees inside while it is 34 degrees outside in summer and 12 degrees inside while it is zero degrees outside in winter according to calculations using the result of experiments with models. We will experiment at an experimental house. At the house, the roof will be thatched by grass or straw, roofed with shingles or combined by them. The western wall will be cobbed for heat storage and the addition of buoyancy. In addition, projects on rain water use the output process from a toilet, contribution of trees on thermal conditions and so on. The house should be built with nature-friendly materials which nicely return to nature. In such a way a dream expands.

These projects will be done practically with my students at the house, which offers a place to discuss and experiment with them. The dimensions of a sink, the tread and rise of a step, the height of a hand rail should not be decided by a book. Building methods and details for designing a house should be learnt practically from work at the site too. A few similar discussions were held in Japan. Unfortunately, the present circumstances there, which are based on cheap fossil energy use, do not welcome this attitude, nor bring up and develop them, until it gets to a fatal extreme. Fortunately, I have some friends in New Zealand with whom I feel the common basis of understanding and I want to bring back the results as a message from that country. There are a few other reasons NZ was selected. Among others, land is not expensive, we can contribute towards international mutual understanding and the time difference to Japan is not great.

We have to think of other reasons why this kind of concept can not be developed in Japan. The research, study and education for housing, which is the fundamental shelter for the basic unit of a society, i.e. a family, is disregarded. Practical activities in this direction are never seen. For instance, if we look at the curricula at universities, we notice they are aiming to educate students to build large sized buildings with mass-produced building materials. One of the reasons is that there is too much weight put on Structural Engineering in the distribution of laboratories and staff in the Department of Architecture. There is only a single specialized staff member for Structural Engineering out of about twenty staff total in the Dept of Architecture, Auckland University. In addition, he teaches the subject using models to explain instead of just theoretical formulas. They have five staff for Architectural Environmental Engineering and the other staffs are in the areas of designing and planning. On the other hand, Structural Engineering in Japan has been divided and separated by different methodologies and boundary conditions, and has developed in a different way. It is now at a certain maturity and should be thinking about how it could serve Architecture rather than the development of itself. It is only one of the factors in Architectural Planning. Architecture has to "find" a new and true direction.

There needs to be more emphasis on designing and planning a better and more durable house of good quality. Yoshida, the first Japanese prime minister after World War II, encouraged people to recover the then ruined country by building factories rather than houses, while the German prime minister of the same time did the reverse, promoting housing rather than factories. I used to visit a friend of mine in Germany for more than thirty years every few years. Every time I found that he lived much better than I did, say 10 years ahead of me. I can't compare with him any more because I can't buy a piece of land in Japan.
Whatever the situation is we must not let our Architecture "find" the end of the world.

Easily obtained and cheap oil is the target of greedy people and its mass use creates various social hazards as well as the greenhouse effect. These greedy economical deeds yield unsolvable and poisonous chemical substances, poisonous heavy metals produced through the production process, accumulated radioactive wastes, antibacterials, substances that cause ozone depletion and so on. Fossil energy is likely to run out in forty years time. It will apparently leave us decadent and destroyed.
In the past if it snowed, we would get a snow fence, if the sun was strong, we would use a water reed screen. With a little work, the situation could be made much better for a lengthy time. We must not seek to do everything for convenience and too much comfort. We must not forget to strengthen our immune system through the change of seasons and to know the joys given by them.
It is known that fossil energy will finish sooner or later leaving only contamination and pollution. The construction of a large building consumes a lot of energy and huge energy amounts are spent there daily. No arguments can arise on this subject. The end of fossil energy will come earlier and suddenly due to developing countries also using it in the same way. We will be thrown into chaos which can be easily imagined, blaming and swearing at each other. Already weakened immunity will become worse, human values will continue to decrease, and discrimination will become prevalent.

How can the present society which allows these situations be reformed? We can't find any proper way when we construct a society to rely on and use each other too much. We have to break with this old way and start to establish a sustainable way of living for individuals. I think this is the only way that we can choose now. We need something where the origin is oneself and an individual is free and liberated.
Some say that we could find new energy sources. However, it would be just an extension of present decadent concepts. At the same time, if they were to be found, we would be chained to a strongly structured society in the same way as now. Reminded of how wonderful it is to have contact with nature, we shouldget the origin of a new start there.
In order to develop this concept, we have to establish not qualitative but quantitative insistence, else we will be washed out by strong economical power and the end result will be sterile discussions. After precise measurements and their analysis, this development can be simulated and then quantitative discussions will follow. We have to know that with a living plan that these results are only from simulations, and we can have inestimable joy to create with an awareness of coexisting with nature.
Eventually we can not establish a sustainable way of living until we deny greed and return to living a modest life. For that reason, we have to deeply and seriously think over the purpose of one’s life. I am not giving this proposal just to deny the present situation. If we are based on a sustainable lifestyle relying on solar energy in a low hierarchy society, we can be free and liberated from power structures, and have a humane, peaceful and happy life being surrounded by nature. I compare the meaning of a sustainable life with the present society just for explanation. If we live in nature, it is evident that effort will be soon rewarded.

Even though we are given 15,000 times the energy that we use, it must be shared with the environment that gives us wonderful joys. It must be used also for our great surroundings, birds, fish and animals, flowers, trees and grass, and winds, seas and rivers. It is said that joy is an impulse from the gods. The existing space that is created by the gods and its maintenance is absolute. From there we get the concept to live in a modest way. We must be warned against using all the solar energy for human beings in luxurious ways, while we should feel the greatness in the way this huge amount of energy sustains our earth. Let's understand that we should use only this 1/15,000 and let great nature encourage us to carry out a sustainable way of living.

At the realization of sustainable living, if it is expressed that we can live as long as the sun exists, this is the root of materialism. We have to be beyond it and develop ourself spiritually which means a movement to the next plane and its discovery. These facts and directions must be well understood by our generation as well as future ones, and education and research are urgently necessary. The knowledge and habits which are obtained in childhood are accepted naturally and are not bothersome. If many of following generations aim at a sustainable way of living, we could get there earlier.
We have to establish a social system for recycling and reuse and use of our limited natural resources, even if it is transitional. If they are mixed, they are just rubbish, but if they are well classified, they are precious resources. It is good that in Japan plastics are collected by type. If it could be directly connected to reuse, it would be much better however. For instance, recycled plastics could be used for the construction of an Ozeki septic tank, which will be mentioned later, and last longer than a tank using iron plates. I would like to inspire and encourage people in this field.

Population is an important issue. In finding how much land we need for a sustainable way of living, we need to have a firm and global consensus. We have to decide together how much land we need to live sustainably. This is one of the most important projects. Shaking off the desire to need more and more, we have to move to a place that enables sustainable living. For instance, instead of looking for more copses for wood, we should determine the amount to be used. Then we should stock this amount, feel secure with it, and need not work harder.
Communication systems like the Internet and email can transmit mutual information and knowledge and we can elevate and uplift ourselves. Quite a number of people have already visited my website not only from Japan but from all over the world. Such spontaneous exchanges are very important.

It will not influence anything, even if I do this.
This much doesn't affect anything.
If you are so strict, you can not eat anything.
It is too late.
Somebody will do something, it will be managed.
Recently things are like this.
Many do this.

We often hear this kind of conversation. I want to warn them of what can be found beyond this

Motive to commence the project

The project was not a sudden inspiration. My major field, Architectural Acoustics, involves the control of Auditorium Acoustics to enable good musical performances including suppressing uncomfortable noise. I was involved in noise surveys and social questionnaires which resulted in the suspension of landings and takeoffs after 9pm from Itami International Airport. It is a pity that this airport is still active after the Kansai International Airport was opened on an artificial island. I worked to reduce the impact sound of aluminium baseball bats. Through this work on noise control, I was also involved in air pollution, water contamination etc. Further, when we performed the synthesized evaluation of a room environment with noise, thermal conditions and lighting, thermal conditions was the dominant measure on the subjective scale of uncomfortableness, above the two other factors. The quantified result explains clearly why we tend to open windows in summer to get outside air even in a noisy environment. It also means we can not avoid the issue of energy.
I planned to build either a sustainable house for my lab in Okinawa right after it was returned from the US or another proposal to a certain alumnus of the lab where I was a student. However these plans were not realized. The following reasons led me to decide to come to NZ: I had many good friends in NZ through Acoustics; the land is not expensive; labour and construction material costs are reasonable; it provides good opportunities for students to engage in international mutual understanding. I brought more than 30 students in total to NZ while I was on the staff at Kansai University in Osaka. After 28 years work I resigned at the age of 60.

The present education for Architecture focuses mainly on large sized buildings which consume huge amounts of energy. Teachers who have never even built a house teach Architecture - I was one of them. Consequently, they don't know there are enough large sized buildings and a saturation point has been reached, and they can't navigate in a new direction. When I was invited to the preparation workshop of the World Exposition at Hanover in 2000, I met an American Architect from a well known Architect office, and he said that they don’t need any new buildings because they have already built enough for people in the United States.
The thing that is urgently necessary in society is to have space for practical work for sustainability and enable related research to absorb young people who think seriously about their future. As the present situation in Japan does not offer any such place, I thought the project would be a good place to start. If a university is a place only to teach and educate, the Internet can replace this. However, we need places where we do research and have the consensus of a university to contemplate all of human society. If large and expensive equipment is obtained or constructed, free access should be available for people to come with creation in mind. A large facility or a plant with extremely advanced technology should be open to the public with regard to how they are used. If it is occupied by capital, even people there would be restrained. Free access will yield great creative development, collecting each one's inspiration.

After all, past public nuisances have never been fundamentally solved. Minamata's organic mercury, Yokkaichi’s smog, Morinaga's arsenic and so on, still exist in a distorted form and people do not pay any attention now. We don't feel anything for the eternal loss of the delicate and fine beauty of rare species of plants and animals. Before we admire them, they are gone and never come back. To which corner in the soul world did we push them away? It is evident that we have done that. Crows, sparrows, wasps and other unwelcome existences are widely spread. Concrete buildings, factories that are only functional, ugly things are dominant. Only ugly people are dominant and leading the world. The world of feeling is made into a desert as well.

Experimental project at Kaiwaka (KW)

With the above way of thinking in mind, we developed the following practical goals for the sustainable project and have been trying to realize them:
(1) To live using natural energy
(2) To build a house using locally grown and/or existing materials
(3) To live without producing any contamination from daily life
(4) To be self-sufficient by organic farming, and
(5) To have a joyful life
One by one, the present situation and plans for the near future are presented in the following sections

(1)Energy from nature

1-1) Individual item for house planning
The amount of solar energy that falls on the earth in a single year is 1.21x1017wat/hr. This corresponds to 15,000 times the energy that human beings use in a year. If applied to Japan, the solar energy falling on the land is 100 times the amount used by the entire population. If the 200 sea miles of surrounding ocean area is included, this goes up to 1,000 times.
To give an example of the power of solar energy, if 10% of the six main world deserts were to be covered by plants, and their energy through photosynthesis exchanged with an efficiency rate of 5%, the energy obtained would match the predicted energy needs of the world in the year 2020. (Horigome Takashi:'Kagakuasahi' p.16, March, 1991)
From this it is apparent that we can establish a sustainable lifestyle by relying on solar energy. The following are the efforts done at the experimental house to utilise solar energy in direct and/or indirect ways.

1-1-1) Bio-gasification using the Ozeki septic tank
The first item in this section is an Ozeki septic tank. Although the produced amount of energy is not huge, it completely gasifies all bodily waste as well as garbage. It makes sewerage infrastructure unnecessary and also saves a lot of energy. I learnt of Hiroaki Ozeki, the inventor of the septic tank, through a NHK TV programme on his septic tank. I thought it had interesting possibilities for my project and I firstly sent a few students to visit him. I visited him some time later. He had a broad general knowledge and enjoyed those things he felt meaningful for human life. Unfortunately, he passed away on the third of March, 1999.
When I first listened to his explanation of how his tank worked, it was very persuasive. "Prof. Sakurai, think of any degradable organic things, if you leave them outside, they vanish in 125 days. So, the decomposition in my tank goes very slowly." However, for so called academic societies qualitative expressions are not accepted as papers to be published in their journals. Immediately after I met him, we visited a local iron work at Warkworth and asked them to make a smaller septic tank. Following his directions and suggestions, the septic tank was able to produce bio-gas easily. I persuaded him to publish a paper on the Ozeki septic tank to transfer his knowledge. He accepted finally on the condition that I became a co-author for the paper with his colleague. We chose 'Solar Energy' to publish in. I visited his home several times and learnt more about the tank directly from him, and wrote a manuscript with his checks and corrections. Finally, it was published as the reference shown at the end of this section. The ways to construct an Ozeki septic tank and how to use it are presented in it. A booklet written in English has also been printed - please see it or Chapter 5 for further information. In this section, an abstracted explanation is given along with our experience at the Kaiwaka Experimental House. In NZ, the surrounding oceans are contaminated by fertilizer and animal waste and run-off. I hope the following could be helpful in cleansing it. Bio-gas itself accelerates the greenhouse effect, and it should be used for energy while the burnt gas should be processed.
Hiroaki Ozeki, Y.Sakurai and F.Niwa; 'Biogas generated from organic waste in a septic tank', Journal of the Japanese solar energy, vol.25, No.2, p53-60(1999) (in Japanese).
An English written booklet is available NZ$20. Contact Yoshi on email or with a letter.

Human discharge, organic waste, as well as animal manure are mostly discharged through drains and pipes into rivers and the sea, after they have been partially cleansed. Some is removed by trucks and burnt -this consumes a great amount of energy producing carbon dioxide. The discharge of waste into rivers and the sea supplies rich nutrients, suppressing the natural self-cleansing process. This problem needs to be urgently taken care of in conjunction with other environmental problems.
For the protection of the environment, a sustainable way of living plays a vital role as it is in tune with nature's natural cycle. Human activities must not be allowed to break that natural balance. It is assumed that the energy used by human beings is 1/15,000 of the overall solar energy radiating onto the earth. This energy is partly used for agriculture to grow food for human beings and animals, and the waste should be taken care of in accordance with the natural cycle thus inflicting no harm on the environment. In this section, the septic tank for creating bio gas from any rottable organic waste is explained.

A) Bio gasification process
The process of bio gasification has two steps of fermentation. The first stage is acidic fermentation, i.e. the liquefaction process. In it, complex organic wastes are first broken down by the activity of facultative anaerobes into soluble low molecular weight materials. Then they are decomposed by the activity of obligate anaerobes into low fatty acid. In the second stage, i.e. bio gasification process, the low fatty acid is transformed by methanogen activity into methane and carbon dioxide etc. These gases together are called bio gas. The reaction systems of bacteria are shown and explained in Fig.1-1-1 with reference to the digestion of food in the human body.

Fig.1-1-1 Ozeki septic tank processes in comparison with human digestion.

It has been widely believed that the temperature range for bacterial activity is from 30 to 40 deg, and usually the liquid in a septic tank has to be heated up to this temperature. In our septic tank, bio gas is naturally produced in the low temperature range of 15 to 25 deg without any heating. The septic tank is conveniently installed under ground where it stays in that temperature range. We have heard that bio gasification can work even when the outside air temperature drops to -20 deg.
Thus, the temperature range of methane bacteria activity in our septic tank is quite different from the range which has been believed necessary before, we call them low temperature methane bacteria. It is believed that the bacteria adjust themselves to the low temperature in the septic tank. This finding eliminates the need for a complex process to heat the liquid up and at the same time saves the consumption of energy.
When we observe any organic waste left in nature, they are completely degraded in approx. 125 days. This does not happen only in high temperatures. That means if waste is processed artificially and unnaturally, for instance in specially raised temperatures, the rest of their energy, which is degradable, will remain as residue in the septic tank.

B) Requirements for bio gasification of large amounts of organic waste
Considering the natural process of bio gasification mentioned above, a septic tank for large amounts of organic waste was designed; its dimensions are given in Chapter 5.
It is made of iron plates and the parts that are exposed to air are of stainless steel plates. It is necessary that the parts are carefully double welded together to avoid any leaks of air or water. These dimensions apply to allow proper functioning of the bio gasification process. They must not be made any larger for bigger quantities of waste. If they exceed these limits, the waste can not evenly ferment, especially at the rim. When a larger amount of waste is processed, like waste from livestock, discharges at places where many people gather and so on, an appropriate number of septic tanks should be installed according to their capacity as mentioned further on.

The outline of how to use the septic tank is given below:
1) Anaerobic conditions
Methane bacteria can be active only under anaerobic conditions.
2) Place of installation
As mentioned above, the septic tank uses natural fermentation with low temperature methane bacteria, and must be installed under the ground where it is sunny and not facing a strong cold wind in winter and where underground water runs lower than it.
3) PH value
Organic wastes for the septic tank should be of a pH value of 7.2 to 7.6 which is almost neutral or weak alkaline. If there is much urine, the pH value rises to over 8 and it is important to adjust the pH by adding acid producing materials, such as organic garbage, rice bran, maltose or similar.
4) Natural stirring
The liquid surface rises as bio gas is produced in section (B), and when the bio gas is extracted, it sinks. Then the liquid moves in the septic tank and is stirred naturally. No artificial work is needed which is just like natural movement in the human stomach and intestines.
5) Seeding and preparation for the continual use of the tank
These processes are very important and will be explained in detail later on and in Chapter 5.
6) Material to be loaded
Any kind of organic material that rots, such as human discharge or those from domestic and dairy animals, leftover food and organic garbage, meat etc, can be bio gasified. However, the length of time and efficiency of the bio gasification for each item varies, depending on the rotting process.
7) Amount of organic waste
Usually a septic tank that ferments in the middle temperature range is loaded with 2 to 3 kg/m3 a day and for high temperature with 5 to 6 kg/m3 a day. However, our septic tank has a natural fermenting process and can be loaded with 1kg/m3 a day, maximum. The amount of loading per day is given in Table 1-1-1, though this depends on the local climate.

Table 1-1-1 The amount of loading per day.

8) Density of solids
The best density of solids in the septic tank is at the ratio of 6 to 8% of the whole weight.
9) Duration of through-put
The septic tank's capacity is about 70 to 80 times the usual daily input including water. However, as it is designed to simulate the natural rotting process, it stays a relatively long time in the tank; even in summer it takes over a hundred days. The length of stay in each section of the tank is shown in Table 1-1-2.

Table 1-1-2 Waste stay in each section according to climate.

C) Production of bio gas
1) Components of bio gas and respective quantities
It is self-evident that the components and their respective quantities change depending on the organic waste input. The overall results of the gases are given in Table 1-1-3 called bio gas.

Table 1-1-3 Components in biogas and their respective quantities.

Hydrogen sulphide, ammonium, indole and skatole are sources of bad odour. However, these smells can be absorbed by de-sulphurisation material.

2) Amount of bio gas
The amount of bio gas produced per kg of organic waste is 0.1 to 0.7m3. Accordingly, the amount produced by the septic tank varies from 2 to 21m3 per day depending on the kind of waste. The flame temperature of the burning bio gas is about 188°C. The calorie range is from 5,500 to 6,500kcal/m3, with an average of 6,000kcal/m3. For reference, volumes of other gases that have the same energy as 1m3 methane gas are shown in Table 1-1-4.

Table 1-1-4Volumes of other gases that have the same energy as 1m3 methane gas.

The small septic tank that is installed at the Kaiwaka Experimental House in New Zealand produces bio gas on average every day to boil one third to a half cup of water per person's discharge and refuse. More precise data will be available at a later point. A larger size tank has the same digestive speed. From this we can say that the amount of energy corresponds to less than 1% of the daily caloric intake by an adult, and can be returned as a form of natural energy for each person.

D) Sludge, pathogenic fungi and parasites
1) Residue and sludge
As mentioned earlier, if the septic tank is operated properly, almost all organic waste is turned into bio gas, and there is no sludge-like residue left, and no overflow.
Though the reasons are not fully understood, the following are considered;
i) All organic waste naturally disintegrates within 125 days. After inputs are entered into the septic tank with no forced artificial processing like heating and stirring, bio gasification takes a long period of time - over 100 days even for human discharge.
ii) The bio gasification process is explained by an experimental formula as follows;

(Propionic acid) (Water) (Acetic acid)(Carbon dioxide)(Methane)

2C3H7COOH + CO2 + 2H2O --> 4CH3COOH + CH4
(Butyric acid)

CH3COOH --> CH4 + CO2
(By the methane bacteria)

It is also thought that the density and species of bacteria in the septic tank are in a good equilibrium with each other as they are not forcibly stirred. Thus, if there is a good balance between the groups of micro-organisms which produces organic acid from complex organic material and the one which ferments the organic acid to methane and carbon dioxide it is thought that nothing will remain unprocessed in the septic tank.
iii) As the dirt accompanied with animal manure and garbage accumulates in the tank, it should be eliminated at intervals - probably only once every ten years.
2) Pathogenic fungi and parasites
There are two ways to sterilize pathogenic fungi and parasites; one is to boil them and another is to put them in anaerobic conditions. In order to improve sterilization in the anaerobic septic tank, a barrier is installed at the end of section (B).
In the inspection section (C), the longest life span of each species was observed as shown in Table 1-1-5.
When their life span length is cross-referenced with the amount of time spent in each septic tank section shown in Table 1-1-2, it is quite evident that these pathogenic fungi and parasites do not come out of the septic tank.

Table 1-1-5 Longest life span length in the septic tank for pathogenic fungus and parasites.

Fig.3  Another way to install the barrier to eliminate pathogenic fungus and parasites.

As long as the septic tank has a steady fermentation process in winter, it will shorten the life span in summer.

E) Seeding and fermenting for daily standard use
1) Seeding
It is critical to seed the tank prior to starting to use the septic tank.Chapter 5 details the steps to do this – it is very important to do this correctly.
First, the gas cock at the exit of the septic tank must be closed. 20 tons of human discharge which have been kept in conventional toilet tanks should be introduced to the septic tank. Water is added from the inspection manhole to the lower dotted line in Fig.5-2-1 of chapter 5. The discharge from a flush toilet must not be used as it is urea-decomposed and can not be bio gasified. Secondly, fifty bagfuls of 15kg dry chicken manure should be added through the entrance of the septic tank.
The gas first produced is air which should be released until the pressure shows zero, and then the cock should be re-closed. This procedure needs to be repeated three times. If it produces fire after the fifth time, the septic tank has been seeded successfully.

2) Preparation for daily standard loading
Following the seeding in 1), the system needs a gradual increase of organic waste input to reach the stage of daily steady input. The situation can be compared to the growth of a child's stomach to the one of an adult. This process is different depending on the kind of loading material. Now, the septic tank can accept the daily steady input in Table 1-1-1. Although this preparation process is explained for each kind of organic material in Chapter 5, the same amount of water as that of the organic material should be added each time. However, in the case of human discharge, containing urine as water, only half the proportion of water is required. Therefore, careful consideration should be given to how much liquid any input contains.
Thus, it is very important to start the bio-gasification with a small amount of waste and then gradually increase it. When a steady amount of input is reached, the daily input chart should be followed as indicated in Table 1-1-1. The above given data is for seeding preparation in summer. For spring, seven days should be added, for autumn, 15 days, and for winter 25 days. 12kpa of pressure should be maintained for the methane production to be most efficient. When bio-gasification works normally the gas should be used as it stimulates the remaining waste to move along the bottom slope and ferment into bio gas.
A marine toilet should be used which flushes 280cc of water by pressing a foot step. Thus a few pushes of the step for each use adds the proper amount of water. If a water spray washing device is attached, the water running from this device can be a replacement, and there would be less use of paper.

3) Deodorization of biogas
Deodorant to eliminate sulphides which create a bad smell, such as hydrogen sulphide, can be commercially purchased. The one at the Experimental House can be used for 25 years in a cylinder connected to the septic tank. To reuse the deodorant, it can be exposed to the outside for a month on a mat and its black colour will return to the original brown colour.
F) Small capacity septic tank for family discharge and refuse
The dimensions for a small Ozeki septic tank for family use are shown in parentheses in Fig.5-2-1, Chapter 5. The barrier to suppress pathogenic fungi and parasites can be installed as shown in Fig. 3 of the recently printed pamphlet.
The seeding for this tank should also be done very carefully, following these instructions;

i) Fill the septic tank with water to the lower dotted line in Fig.5-2-1, Chapter 5.
ii) Place 7 tons of old human discharge in the first section. As mentioned before, discharge from standard flushing toilets must not be used; as they are already urea decomposed and can not be methanized.
iii) Add forty 15kg bags of dry chicken manure.
iv) Wait until the above are bio gasified.

If human discharge can not be obtained for step ii) 70 bags of 5kg of dry chicken manure can be added instead.
At the Kaiwaka Experimental House, about 1.5tons of chicken manure including urine, sourced from a chicken farm, was added to the septic tank for step ii). Within a week, bio gas was produced and the pressure reached 15kpa. After this only human discharge and organic waste were used and the pressure gauge now stays at about 8kpa, because the daily input is on average from just a single person. However, even this supplies enough daily energy to boil one third to a half cupful of water (More precise data will be given later). The liquid level in the septic tank is kept just at the overflow level.
In daily use, the recommended ratio of human discharge to additional water is 2 : 1. Any rottable organic material other than human discharge can be put into the septic tank, as long as the ratio of solids to water is kept at 1 to 1. To produce methane gas CH4, one carbon needs four hydrogen atoms. It is estimated that human discharge contains only two hydrogen atoms and therefore another 2 must be added with additional water. The water amount needed is less if organic refuse from the kitchen is added.
At the Kaiwaka Experimental House, a marine flush toilet is installed that releases 280cc of flushing water by pressing down a foot step. In order to supply additional water instead of using large amounts of paper, a water spraying washer is attached to the toilet seat.

The maximum input for a day is 20kg of human discharge and 5kg of kitchen refuse. A person produces about 1kg of discharge a day. If only 5kgs of human discharge are put in, 20kg of refuse can be added. Green grass can be put in as refuse, as it contains quite a large amount of water when it is green. The important thing here is again not to exceed the given limit that is mentioned above.
At the Kaiwaka Experimental House, the bio gas produced is used for cooking. The gas flows from the septic tank through a deodorant, via a pressure gauge and a regulator to the gas burner in the kitchen as shown in Fig.1-1-2. A gas burner for biogas use has not been specifically designed, i.e. one which can be adjusted by a cock is used.

Fig.1-1-2 Practical use of biogas for cooking at Kaiwaka Experimental House.

In the beginning the toilet to the septic tank was connected by a plastic pipe 2.6meters long, 20cm in diameter which ran under the shower room. This meant that it was hanging under the basement ceiling. The reason why it was horizontal was that if it was slanted, it would be clogged up as it dried. If it is horizontal and has a drop at one end, it drops to the septic tank in the other end. However, it was flushed after the lid was covered and the reason why the toilet was dirty was not found for a long time. The reason was the pressure produced in the horizontal pipe and the first section meant part of the energy was lost. As a result, the toilet was moved to be just above section A of the septic tank. Even there the pipe from the toilet to the tank has to be slanted and flushing is done carefully.
To solve the smell from the toilet, the house plan is very important. It is recommended that a toilet extends from the house allowing ventilation from the outside air. It must be thermally well insulated especially for winter use. Its floor needs to be at least 1m x 1.7m. The width of the tank is 1.5m and the first section is only 50cm long. A few examples of toilet location are shown in Fig.1-1-3.

Fig.1-1-3 Location examples for a toilet and Ozeki septic tank.
An important thing to note is that it should be dropped directly above wherever the tank is installed. A chute should go straight to the tank too. If a down pipe is slanted even for a short length as at the Experimental House, sometimes it should be pushed down to the tank. Both entrances in the tank must be as far apart as possible so as not to cause interference. Bad smells does not occur much because of the escape pipe which is connected between the toilet and the tank. As some gas is produced in the first section, and the pressure is higher than normal atmosphere, the outside air does not enter the first section and the anaerobic condition there is kept.
If it becomes necessary to expand a pipe, it should be kept horizontal and less than 2.5m long, and two bucketfuls of water must poured in once a week to keep it liquid. The gas produced in the pipe is considered normal and an escape pipe for it is a good idea. The quality of the gas should be tested though. Once the gas pressure reduces to zero, it takes some time to get back to the steady usual pressure. Especially in winter, it takes longer time to recover.
The Ozeki Septic Tank at the Experimental House is completely constructed by iron plates. A lot of rust is found after 12 years where plates are exposed to air. It is a good idea to replace such parts with stainless steel. To use new plastic for it should be out of the question. If you limit use to recycled plastic, if a tank is made with it, it should also last longer. Further improvement will help to have a more comfortable toilet.

G) Other aspects to be considered
Most of the malfunctioning has been caused by overloading or when the water ratio was not correct. As explained in Fig.1-1-1 the tank operates in a similar way to the digestive process in the human stomach and intestines, thus it must not be disturbed by using it improperly.
If the bio gas is kept for a long time in the septic tank, nutrients for the methane bacteria become low. Therefore it should be used constantly.
As it uses acid fermentation, strong alkaline containing material, such as soap water for cleaning the toilet and after washing, must be avoided.
Materials not to be put into the septic tank are; stones, sand, plastic, rubber, sawdust, rice grain, shells and so on.

We would like to emphasize that the septic tank does not leave any residues or sludge. This means that the pollution of rivers and the sea with a lot of nutrients can be avoided, and the energy required to burn human discharge and refuse can be saved and accordingly carbon dioxide production can be eliminated.
The amount of energy produced in the Ozeki septic tank from the waste of one person is not much: Enough to boil just onethird to a half cupfuls of water per day per person, depending on the season, however it is a sure way to get energy daily from a human's eating habits. If more gas production is desired then additional biomass should be added.
The bio gas is kept under water in the septic tank and is pushed out by its own pressure. There is very little risk of explosion, even if a fire should occur above the septic tank.
It would be meaningful to think and look at making the septic tank from used plastic, because it lasts longer. However, to minimize the environmental impact this should be strongly limited to reused plastic.
Human discharge from toilets in public transport stations such as airports, bus and train stations, public meeting places, restaurants, leftovers and refuse from restaurants, waste from stock farms, and so on, all could be converted into energy.
A good starting point would be to install tanks at milking sheds and produce electricity from them, and then New Zealand’s oceans would be cleaner among other results.
The carbon dioxide from burning bio gas can be channelled to growing plants whereby photosynthesis changes it into oxygen in an enclosure such as a greenhouse. At the Kaiwaka Experimental House site, we have a greenhouse for this purpose. An air duct from the cooking range hood in the kitchen leads to the adjacent greenhouse with three ponds where rice, azolla and other water plants grow. The burnt gas falls over the grass in the ponds.
In this way, human activities do not inflict any extra load or harm to our precious earth, and a sustainable system can be completed.

The authors are grateful to Mr. Hideo Nogaki, former chief of pharmaceutics at Japan Rail, for his measurements of the life spans of pathogenic fungi and parasites in the septic tank. They also wish to appreciate the help of Mr. Allan Neilson in publishing a booklet.

The inventor's family will be happy to see the Ozeki tank produced for use in protecting nature. If you intend to use the design to build a number of these tanks for sale then please contact Yoshimasa Sakurai to discuss a small royalty payment per unit for the inventor's family.

For copies of the booklet contact:
Yoshimasa Sakurai
Experimental House, 112 Gibbons Rd, R.D.2 Kaiwaka

1-1-2) Direct solar energy collection
As mentioned before, the solar energy falls over the earth in huge quantities. Without forgetting that it needs to be shared by all creatures, if we collect it to use for our lives, it is very useful and precious. The following is from a paper which was submitted to the journal of the Japanese Solar Energy, with some parts being omitted and a few comments added.
Y. Sakurai,"Solar Energy Collection- the second report from Kaiwaka", Vol.22, No.1, p15-23(1996)

It is difficult to rely on one kind of energy for maintaining a certain standard of living a sustainable life, and it is better to collect as many varieties of solar energy as possible. Temperatures at various points of food cooking were measured, and how temperatures for cooking could be obtained from solar energy and other practical experiments were investigated. These include a solar oven, a solar cooker, a system to get hot water, energy collection from sky radiation, energy collection with porous materials, and so on.

(1)Temperature change during cooking
We conducted four experiments investigating the temperature and the amount of energy required for cooking and how this changes over time. Some dishes were cooked and measurements taken. Using these results we could determine what type of solar radiation collectors or biogas heat should be used in different situations. The temperature was measured by inserting thermocouples into foods or by measuring the surface temperature. Measured points are shown in each sketch.
Fig.1-1-4 shows an experiment where a chicken leg (207g) was cooked in a gas oven with dimensions of 30.5cm X 29.3cm X 18.5cm using low heat (160deg). It took 50 minutes to cook satisfactorily. However, when the temperature was raised to 230deg, it only took 15 minutes. A fan was used to minimise the air convection layer to improve the heat transfer. It also helped with temperature distribution.

Fig.1-1-4 Temperature change during grilling a chicken leg in a gas oven.

Fig.1-1-5 shows the temperature change when a steak (140g) was cooked in a frying pan at a low temperature. It took 6 minutes to be cooked through. When food requires a lot of heat to cook, the pot used in the solar cooker should have some heat storage and a high surface temperature. A hundred fifty degrees is sufficient to cook a steak.

Fig.1-1-5 Temperature change in a beef steak cooking on a frying pan.

Fig.1-1-6 Temperature change while cooking a stew in a saucepan.

Fig.1-1-6 shows the temperature change when a stew was cooked in a saucepan. The stew was made with a potato, a carrot, an onion and chicken (200g), and braised, then put into the saucepan. It took 30 minutes to cook and the temperature rose to about 100deg. The dotted line shows the temperature change when the saucepan was kept in the thermal insulation box. Three croquettes were fried in 300cc of plant oil. The oil temperature was around 200deg, as shown in Fig.1-1-7.

Fig.1-1-7 Temperature change when three croquettes were fried in 300 cc of plant oil.

If food requiring a lot of heat to cook is put into a pan, the oil temperature drops suddenly. It is important to use cooking devices that are appropriate for the kind of food to be cooked.

Fig.1-1-8 Cooking equipment to improve efficiency.

(a) A thermal insulation box and skirt
As soon as the food in a pot reached boiling point, the pot was removed from the heat and placed into a thermal insulation box. In our Japanese laboratory this box was made of polystyrene while in the Experimental House a box insulated with wool fleece was used. After 30 minutes in the box, rice or a stew was well cooked. The temperature change is shown with dotted lines in Fig.1-1-8 for the pot during rice cooking and for the stew in Fig.1-1-6 (in the previous section). This method can be applied to some food which is boiled, in order to save energy. Surrounding the pot with a metal skirt can also increase the efficiency.
(b) Cooking range
When the wind blows strongly, we can cook Sukiyaki for four persons using an electric pan with the power generated from the windmill. However, we can not expect that much windmill power to always be available. Therefore a cooking range has been designed to utilize a variety of energy sources in the kitchen.

(2) Direct solar energy collection for cooking
Cooking equipment that can convert solar energy directly into heat is described in this section. The experimental house uses a solar oven and a solar cooker for cooking1) as well. Although their use is strongly affected by prevailing weather conditions, they are great devices. When it is fine, we are also able to produce enough heat to cook preserved food and melt plastic to be reformed.
1) B & D Halacy; "Cooking with the sun", Morning Sun Press, 1978.

i) Solar oven
The mouth of the reflector aimed at the sun collects solar radiation that goes through a glass plate cover to the oven at the bottom. The inside surface of the oven is painted black and the walls are highly thermally insulated. The inside of the reflector is coated with very highly reflecting sheets on cardboard. At Kaiwaka, wool fleece is used as a thermal insulator for the walls. The oven is shown in Fig.1-1-9.

Fig.1-1-9 Solar oven aimed at the sun and its section.

The calculated results (dotted line) can be compared with the measured ones (continuous line) in Fig.1-1-10. The calculation used a reflection coefficient of the reflecting surface at 0.7, the transmission coefficient of a glass plate at 0.8, the radiation absorption of a black surface at 0.8, the overall coefficient of heat transfer at 0.64kcal/m2hr C, and heat capacity at 0.352kcal/m2 C. Direct solar radiation on the day of the experiment is also shown, there it changed from 75 to 380kcal/m2hr. The measured result is lower than the calculated one in the later stages because of air leaks.

Fig.1-1-10 Comparison of calculated and measured air temperatures in the solar oven.
(a) Measured direct solar radiation on a partly cloudy day with a change 270-440kcal/m2hr
(b) Measured direct solar radiation on a fine day with a change 590-640kcal/m2hr

In the design phase the dimension of the mouth is one of the important factors and it must meet certain geometrical conditions to utilise all reflected light in the bottom box.
Temperature calculations in the oven were made by using measured direct solar radiation from two different days:

When the area of the reflector's mouth was in the same position as for the previously used reflector, the overall thermal coefficient K, the heat capacity CAP and the oven volume V, were changed. The calculated results are compared in Fig.1-1-11.

(i) Change of an overall thermal coefficient
(ii) Change of a heat capacity CAP (iii) Change of an oven volume V

Fig.1-1-11 Temperature change when three parameters of the oven were changed.

The bottom box is thermally insulated and has good heat storage. The heat storage is for a sunny day with some clouds. A measured result is shown in Fig.1-1-12.

Fig.1-1-12 Solar oven on a sunny day with some clouds.

A device to reduce heat loss is shown in Fig.1-1-13. When the cooking is finished, taking the dish out allows the hot air to dissipate. If the dish is moved into an adjacent compartment as shown in the figure, acquired energy can be reused.
An interesting observation was that the temperature distribution in the bottom box was up to 40 degrees. Therefore the cooking location in the box should be carefully chosen.

Fig.1-1-13 Less heat loss at the change of cooking.
ii) Solar cooker
The reflection of solar radiation on the parabolic surface is focused onto the bottom of a pot as shown in Fig1-1-14. The reflector's mouth has dimensions of 100.6cm x 100.6cm. The distance to the focus is 50cm. The pot is made of aluminium and has a depth of 6.5cm, a diameter of 14cm and a thickness of 0.5mm. The outside is painted black. There is a heat-resistant glass case of 6mm thickness surrounding the pot with a 4cm air gap. The specially designed pot is placed between two parallel iron angles supported by 12mm thick wooden plates. The total weight is about 14kg.
Thermal calculations were done by adding the received solar energy on the small segments on the pot. If each segment faces the reflected light normally, it gets more energy.

Fig.1-1-14 Solar cooker with a parabolic reflector.

In our Lab in Japan we conducted an experiment with a similar cooker. On a fine day the oil temperature was increased by 260deg. Frozen croquettes were cooked thoroughly. The outside air temperature, direct solar radiation, and temperature of the plant oil at that time are shown in Fig.1-1-15. From this, it can be seen that it is not difficult to produce temperatures high enough for frying.

Fig.1-1-15 Temperature change at cooking a croquette.

When material with a large heat capacity, like a steak, is cooked, a pot with its own heat capacity should be used. The thin pot was replaced with one made of 3mm thick stainless steel. In this way it was possible to produce enough heat to well-cook the steak.
Especially in winter, the sun from 10am to 2pm should be utilized.

(3)Other soler enargy collection
i) Solar energy collection by a two dimensional reflector
In this experiment, we covered a black stainless pipe (diameter: 2.5cm, thickness: 1mm) with an acrylic transparent pipe. The air gap was about 4cm. The convection in the air gap was not taken into account in later calculations. The opening of the parabolic reflecting surface was 100cm by 100 cm, and the focal length was 20cm. We moved the reflector by hand towards the sun and the water temperature easily reached boiling point. The calculated result is compared with the measured one in Fig.1-1-16.

Fig.1-1-16 Water temperature change with a two dimensional reflector.

Summer in Japan is characterised by fine, calm and humid weather. The solar radiation collection with a two-dimensional reflector that tracks the sun and generates electricity with a turbine would be ideal for this and similar situations.
Six water containers of 2.8cm deep, 2.4m x 1m wide were made with galvanized iron plates and placed on the solar room floor. The purposes were to store heat for lifting power before the sun rises and to use the warmed water. However, they got only to 27deg at sunset in winter and this was not enough hot for shower water. To increase the gain from the sun, a large two dimensional reflector was installed to be focused on two cylindrical pipes of 18cm in diameter in front. The first one was connected behind the last water container as shown in Fig.1-1-17.

Fig.1-1-17 Two dimensional reflector to aim the sun at 30deg in the solar room.

Two stainless pipes were connected together by a copper pipe and the total length was 4.8m. They were covered with transparent plastic sheets with an air gap of 4cm. The reflector had a mouth area of 1.5m x 4.8m. The temperature went up to 38deg on a winter day, when the surface film was not peeled off. It was not enough hot to have a shower. We tried to raise the header tank about a meter in order for the water containers to face to the sun more directly. However we were not sure if the tower could do this safely.
A circulation pump was going to be installed to a hot water cylinder that was under the floor after the cylindrical pipes. However there have been other priorities for the electricity from the windmill. In addition, the battery effect from two different kinds of metal started to ruin the water containers. This project has been halted and the water containers are empty now. At present, two solar panels are installed outside and used instead, as will be mentioned later on.

ii) Solar energy collection from sky radiation
When we collect solar radiation, current methods tend to use direct sunlight. However, it is important to know how much energy we can obtain even when it is cloudy. To test this, an experiment was done with a black hemisphere filled with water to find out how much the temperature was raised. The hemisphere was covered with a transparent plastic sheet with a 2cm air gap as shown in Fig.1-1-18.

Fig.1-1-18 Solar radiation collection with a black hemisphere.

For our calculations we used the measured sky radiation and the cloud surface radiation was calculated backwards from this. The hemisphere was divided into rings. The solid angle configuration factor of a ring from the cloud surface was calculated and the sky radiation to the hemisphere was obtained by summing up the radiation of the rings. The reflection coefficient of the concrete ground was assumed at 0.1. The water temperature when the hemisphere received direct solar radiation only has been calculated as well. These calculated results are compared with the measured results in Fig.1-1-19. This type of solar energy collection gets more energy from the sky radiation. The water temperature change on a winter day is shown in the following figure. The dotted line shows the water temperature change only with direct solar radiation.

(i) Water temperature change in the hemisphere (ii) Direct solar radiation and sky radiation on the experimental day

Fig.1-1-19 Solar radiation collection with a black hemisphere.

Fig.1-1-20 shows the water temperature change in the hemisphere on a winter day. The outside air temperature and the global solar radiation are also shown.

Fig.1-1-20 Water temperature change in the hemisphere on a cloudy winter day.

iii) Solar energy collection using porous materials
Interesting results were found in an experiment measuring the temperature in cow manure. The results showed high temperature retention of over 50deg, as can be seen in figures of Chapter 5. Later on we did some additional experiments on the roof top of a building with a variety of porous materials. Each material was put in a double cardboard box, and covered with a transparent plastic sheet. All the boxes were arranged in a line in order to have the same exposure to the sun. One of the purposes was to see if the high temperature in the cow manure was because of fermentation or because of solar radiation absorption. The materials used included wool fleece, stainless wool, horse manure, cow manure, cut rice straw, fibre glass. The wool fleece, stainless wool and a few others were painted black and put into different boxes. The temperatures near the surface (4cm deep) and in the middle (12cm deep) of each box were measured. A few results measured on a fine day and a cloudy day, as well as the respective solar radiation, can be seen in Figs 1-1-21 and 22.

 (i) Near the surface (4cm deep)
 (ii) In the middle (12cm deep)
(iii) Solar radiation on the day

Fig.1-1-21 Temperature changes near the surface and in the middle of porous materials on a relatively fine day.

(i) Near the surface (4cm deep) (ii) In the middle (12cm deep) (iii) Solar radiation on the day

Fig.1-1-22 Temperature changes near the surface and in the middle of porous materials on a cloudy day.

Each material shows its own interesting behaviour and the following will be further investigated,

i) The fermentation heat of cow and horse manure produces high temperatures. However, this phenomenon lasts for only one week.
ii) The temperature near the surface of unpainted stainless wool was higher than that of the black painted one.
iii) Wool fleece has high solar radiation absorption and the temperature change from the surface to the bottom was gradual.

We measured the temperature distribution in stainless wool and wool fleece in more detail. The measured temperature distribution in the stainless wool is presented in Fig.1-1-23 along with the solar radiation. The reasons why the stainless wool showed high solar energy absorption are thought to be that the substance itself has high absorption, it is thermally conductive and has heat storage, the mutual reflection between fibres retains heat, and the air in between kept the heat by not allowing air convection.

Fig.1-1-23 Measured temperature distribution in stainless wool.

Using these results, we tried to warm water in a black pipe placed between a stainless wool layer and a wool fleece layer. The measured result is shown in Fig.1-1-24.

Fig.1-1-24 Temperature change in water in a pipe placed between stainless wool and wool fleece.
Summary of this section
If the surface to absorb solar energy is covered with a transparent sheet having an air gap of about 4cm, air convection is prevented and heat can be stored well.
The details of the solar cooker are shown in Fig.1-1-14. The side wooden panels could be lighter if they had some holes. If the reflective surface and the cover glass could be mass-produced, it would be an inexpensive product. The best ways to install it against the wind and material choice to make it as nature-friendly as possible are important subjects to look at in the future. It is worthwhile to introduce a skirt during cooking to use energy more efficiently.
We would appreciate reader’s proposals to develop any of these solar energy collecting tools.

1-1-3) Solar energy collection by solar panels
It was planned to store the solar energy in water while it circulated by means of an electrical circulation pump from the water tanks on the floor of the solar room to a hot water cylinder under it. However, the water tanks should have been slanted more to be more directed towards the sun and so we thought to lift the header tank higher. However, I thought that it was dangerous and that there was the possibility of water leakage because of the connection of copper pipes and tin containers, so the plan was abandoned.
Two solar panels were installed by Don Slater (Solar Solutions) in Sept. 2002, after he was introduced by a friend of mine on Gibbons rd, Lars Hakenberg Van Goothbeak. This commercial system works by thermo-siphoning if a hot water cylinder is higher than the solar panels, and it can be independently installed.
The solar panels installed in front of the shed are shown in Fig.1-1-25. Each panel is

Fig.1-1-25 Solar panel on thermo-siphoning.

125cm wide, 180cm long and 7.7cm deep. Eight copper pipes whose inside diameter is 9mm run from bottom to top and are filled with water, each pipe has a copper wing plate of 142mm width painted black. The panel surface is covered by a sheet of glass. The rear of the panel is thermally insulated.
When the panel is placed at an angle of 45deg facing the sun, warmed water moves upward. A hot water cylinder, which is inside the house and 1.5 meters higher than the panels, is connected to the solar panels, gets the warm water, and returns cold water to the bottom of the solar panels. The black wing plate over a pipe is the heat exchanger. Beneath the pipes there is thermal insulation. In such a way, water runs naturally from the solar panels to the hot water cylinder being warmed up by the sun and as a result the solar energy is stored in the water. This mechanism is called thermo-siphoning. The planned system needed energy to lift water, but it is operated naturally.
First, a shed whose floor is 3m x 3.3m with a height of about 4m, was constructed. Two solar panels were installed in front of the Northern wall at 45deg facing almost directly towards the sun in winter. In the shed, a fire place with a wet back has been placed as shown in Fig 1-1-26. Hot water from the wet back is passed to the hot water cylinder in the same way as the solar panels. It was used during two winter seasons only on some cloudy days. In winter we don’t need toshower so frequently. The warm, sometimes hot, water is usually used for showers, a washing machine and doing dishes. It is a very efficient collection of solar energy and gives a large part of the energy to the household.

Fig.1-1-26 A fire place with a wetback in the shed.

The key aspect of the system is thermo-siphoning. I want to simulate the mechanism and investigate this further, for instance, how it can best be directed for daily use or how freezing in cold areas can be avoided. When the solar panels were installed the hot water cylinder was connected to the header tank where cold water comes through a tap. At the taps, hot water is equivalent to cold water because it is heated by the free energy. I give appreciation to the sun for this.

When the same system is applied to the solar room, the hot water can be used for heating in winter. Namely, the natural circulation between a solar panel and a hot water cylinder stores the solar energy in the day time and the hot water can be circulated to a radiator in the living space at night. The energy to be used by the circulation pump is just the friction in between and needs not much electricity.
On top, the hot air near the ceiling of the solar room can be drawn through an air duct to the basement ceiling just beneath the ground floor. The day time heat will be stored in the walls. This is also thermo-siphoning with air. It must not used below a certain air temperature, say 18deg. By using the two systems, most of the solar energy falling into the solar room can be available for our daily needs.

1-1-4) Fire wood growth (coppicing) and its carbonisation
Fire woods have been widely used as fuel. They fix carbon-dioxide into carbon through photosynthesis. When they are burnt directly or after carbonisation, they release the same amount of carbon dioxide from the air, and the proportion in the air does not change. They are also convenient to store. In England they plan projects to use coppicing and generate electricity by burning firewood, in the scale of the windmills in LA.
They grow trees which are active on photosynthesis and cut them at 1.5m to 2m high when they become a certain thickness. New shoots come out at the cut and from the root. They are cut and stored for winter firewood. This is called coppicing in England. Here in NZ, an experienced person instructed us on how trees should be coppiced, depending on the tree species, growing time, the necessary amount, plantation strategy etc.
At the Experimental House, seven acacias, seven alders, five poplars, four willows were planted around 7 years ago, and now they have grown to twenty meters or higher as shown in Fig.1-1-27.


Fig.1-1-27 Fast growing coppicing trees.

The acacias have already been cut to 1.8m above the ground, and new shoots are expected. The new shoots will be dried and carbonised to be used as charcoal. If the shoots are carbonised, they can be stored and burnt inside the house without creating smoke. They can be a valuable cooking fuel. Trees are composed of carbon, oxygen, hydrogen and trace elements. During charcoal making, they are heated without oxygen and the oxygen and hydrogen is removed. The temperature at carbonisation, which occurs from ca 400 to 1,000deg, creates a different character. They are selected by cooking. Charcoal is used not only for fuel, but also absorption of smell, soil improvement etc. The brown liquid by-produced at charcoal making can be used as an antiseptic. It is said that 1000kg of charcoal is produced from the trees which grow on 1,000m2 of land. I give my trees 500m2 and get 500kg of charcoal. I can use 1.4kg per a day. I want to find out practically how much charcoal I will have at the Experimental House.
At this stage, biogas is used for triggering charcoal and with the help of sheep and chickens, can be used for cooking. I want to design a cooking range with four elements to use the different sources, one with biogas, two with charcoal and one with the electricity from the windmills. Recently, I attended a meeting held by raw foodists. They eat about 85% of their food raw in order not to kill enzymes through cooking. This is a good additional way to save energy.

1-1-5) Windmills
There are three windmills. From the far end of the hill, a 1kw generator, a 300w one and 400w one, respectively are installed. Long pine tree posts are easily obtained in NZ so a post 10m long, 20cm in diameter was buried deeper than a meter, fixed with concrete, and supported by wires tensioned with turnbuckles in three directions. At the top of each post, a corrugated iron pipe of three meters long and 10cm in diameter was attached, then a windmill connected. The height of each post is 9m on the ground. They are shown in Fig1-1-28 with the electrical equipment and batteries. Generated

(i) From the left 400w, 300w and 1kw generators (ii) Battery box (iii) Electrical corner

Fig.1-1-28 Electricity generation from three windmills.

electricity is first rectified and used to charge four batteries of 6 volts connected in series with a capacity of Then, the direct current of 24 volt is fed to the inverter through a controller producing a 50Hz alternative current of 240 volt. When the batteries are fully charged, the controller switches the excessive electricity to a heating element in the hot water cylinder to protect the batteries. As the alternative current has a modified rectangular form and high harmonics, we would like to investigate how a direct current can be used without an inverter or a low pass filter. Even so, it is possible to produce enough electricity for lights and a small refrigerator. On a windy day enough electricity is produced for washing and vacuum cleaning.

An anemometer was set under the middle windmill, but it has now been moved around 7m away to the top of a different post ca 5m tall. The correlation between the wind data and efficiency of each windmill will be interesting to analyse. And its data is used as outside climatic information to predict indoor climate i.e. wind speed and wind direction. The power company in our area called Northpower once recommended windmills for remote farms. They offered periodical checks too. One of our two 400w generators was broken because iron rust broke the copper coil, and it was replaced by a 1kw generator by the company. It is a pity that this section of the company has now been closed.
The 1kw generator is quite sensitive to the wind. In the future the 400w generator will be replaced by at least a 1kw one. The inverter uses a certain amount of electricity to operate.
If a domestic electrical system is operated with a direct electric current, an inverter is unnecessary and the efficiency is better, though the life of a motor reduces, the voltage can not be changed and any family appliances must be changed to operated on direct current. Anyway this is an important subject for investigation for sustainable living. Roughly speaking, the attachment for a windmill is expensive. NZ$15,000 was spent for the total system of two 400w generators and a 300w generator. However, if a social system of recycle and reuse is established the technique can be refined. The 300w generator is sensitive to breezes. It may be left to be available for emergencies while the 400w one should be upgraded to a 1kw one.
The first batteries were used for 12 years but they then finished their useful lives. They will be recycled by specialists. However, a capacitor made of carbon and aluminium has been developed in Japan to store much larger amounts of electricity with much fewer hazardous materials. It is interesting to connect it to the grid too. A lighting bulb could be replaced with an LED light which uses one or less watt. For a battery, the development of a capacitor type is greatly anticipated, because it would be much less hazardous and the natural discharge is small. In general, it is windy in spring and autumn when the atmospheric pressure changes.
If there is no wind but a lot of sunlight, it is possible to use a Sterling engine which has a focus at the hot temperature side with a reflector, and/or a bimetal whose movement can operate rotating gears. Discussion on this is at the end of the section.

1-1-6) Ground heat use
The heat storage of the earth should be really appreciated. The layer of the earth 8m below the ground surface retains the average temperature on the surface, given usual thermal conductivity. At Kaiwaka it changes from approximately 0deg to 30deg with an average of 15deg. The deviation of the annual temperature change in the ground follows the exponential envelope depending on depth, and even at 3.2m deep, the deviation from the annual average is only about ± 2deg. Actually, the basement temperature only changes from 12.5 to 16.5deg. We can use this fact to cool the house in summer and warm it in winter. Pipes imbedded in the ground for this purpose are called cool tubes. They are very useful for a climate which has a very hot summer and very cold winter such as Japan, though we can not neglect the heat island effect there.
We have two sets of three cool tubes 3.2m below the surface which run 10m to the basement from different sides. There is a solar room on top of the experimental house to obtain buoyant or lifting power to get the basement air to the ground floor after the heat is exchanged through the cool tubes. The solar room windows facing outside are double glazed and the walls on the house side are thermally insulated with 60cm of fleece. There is a chimney on the roof to lift the air in the solar room which is sucked through four ventilation holes in the floor and two in the wall. When it is very hot and the air in the solar room is warmed, more cool air from the basement can be brought into the house. See Figs. 1-1-29 and 30. For this thermal technique, the house is constructed to have air tightness, thermal insulation and heat storage. In particular, every opening has triple glazing for later thermal experiment. At Kaiwaka, they are double glazed at present as shown in Fig 1-1-31.

Fig.1-1-29 Three cool tubes vents and the solar room.

Fig.1-1-30 The outlet of a cool tube in the basement.

Fig.1-1-31 Openings with high air tightness and thermal insulation.

A Hume concrete pipe with a 30cm inside diameter is used for the cool tube. The concrete surface in the basement is also efficient in terms of heat exchange. There is a wooden floor 80cm above the floor where one third is open. The open side can be changed depending on the dominant wind direction. Thus, the outside air comes through the cool tubes and there is additional heat exchange with the concrete floor as it comes through to the basement. The heat exchanged air in the basement is lifted up by the buoyancy in the solar room through 12 ventilation holes of 10cm in diameter on the ground floor where there is a living room, a kitchen, two bed rooms and other rooms. This relationship can be described by a calculation linking three equations, firstly Bernoulli's describing air flow, secondly that of thermal transfer, and thirdly that of heat balance in a room. They are shown in Chapter 2.

Temperature changes in the northern bedroom in July 1996 and in February 1997 are shown in Fig.1-1-32, where a continuous thick line shows the measured temperature, a red line the calculated result, and a thin continuous line the outside temperature. If the daily average outside temperature is compared with the inside temperature it is obvious that the ground heat affects the indoor climate. The calculation was done by one of my students Dr. Hirotaka Azumi. More details are given in Chapter 2. The gained heat, in negative numbers, through the cool tubes on the hottest day and the days before and after is shown in Fig 1-1-33.

Fig.1-1-32 Air-conditioning in the northern bed room using ground heat.

Fig.1-1-33 Heat gain from the ground through the cool tubes.
(a)Room temperature change on the hottest day and the days before and after. (b)Heat gain on these three days

In this system, the temperature in the basement is 16.5deg in summer and felt as uncomfortable as an air-conditioner in an office. If one stays there for long, it is necessary to make adjustments with a thick cloth. The air there is always fresh and not the same as that produced by an air-conditioner and all that needs care is the temperature. However, more research should be done on the health implications.
Another point is the leaking rain water from the joints of the cool tubes. They are caught with rain drainpipes at the exit of each cool tube and collected at a corner of the floor. Fortunately the house is on a hill and there is drainage to the creek in front. Rain in winter means a lot is collected but the relative humidity doesn't rise very high. A metal layer 40cm thick surrounds the outside of the concrete block basement walls;a perforated drain pipe 10cm in diameter has been placed at the bottom which funnels all the rain water to a corner. The purpose of the system is for the basement not to be lifted by rain water buoyancy. The rain water which leaks through the cool tubes is removed via the outside drain pipe.
1-1-7) Plans for the near future, experiments, and challenges
Cooking range
A cooking range will be placed in a corner in the kitchen. It has two charcoal ranges, a biogas range and an electricity range. The main cooking range use charcoal, but when I look back on my childhood fire triggering with this kind of range was very difficult. Thus biogas will be used for this purpose. This is an urgent project as is charcoal making. A sketch is given in Fig.1-1-34.

Fig.1-1-34 A cooking range using a variety of energy sources.

Upgrading of the windmills
It has been proven that three windmills are useful. They give us a certain useful amount of energy with the atmospheric pressure change in spring and autumn or during unstable times in winter. The 400w generator will be replaced to one of the same type as the 1kw generator.

Electricity generation by a Sterling engine
The wind does not blow strongly in the Japanese summer, but the sun is strong. Electrical generation by temperature difference can be utilised. A Sterling engine is an external-combustion one and has high and low temperature sides. Both are connected through air and generate a piston movement if the hot side is heated. The movement can be transformed to rotation with two driving wheels. It was invented in the early 19th century in Scotland. Its model is shown in Fig.1-1-35.

Fig.1-1-35 A model of Sterling engine.

Solar energy can be focused on the hot side with a reflector or a Fresnel lens. The cold side can be exposed to the surrounding air. The rotation of the driving wheel is used for electricity generation. Tracking the sun is done on a rotation table, with the time and location of the place obtained from a calculation with a small computer, whose electricity is obtained from the engine. The resultant electricity will charge the batteries for the windmills.

Electrical generation by a bimetal deformation
The deformation of a bimetal that is proportional to temperature can be collected as shown in the following sketch Fig.1-1-36. The back and forth movement can be transformed to the rotation of an attached gear. It will be changed to a faster one with a few gears and be set in a thermal insulation box which faces the sun. The temperature there is expected to be more than 250 deg.

Fig.1-1-36 A sketch of electricity production with bimetals.

Heating system with solar energy gained from the solar room
We have seen that the thermo-siphon is useful to store solar energy. By having the system in the solar room and storing the day time solar energy in the hot water cylinder, we can send the heat to a radiator on the ground floor for cold winter nights. I hope the trusses are strong enough to support them. Having a solar panel on the deck and a hot water cylinder in the attic, the height difference between them decreases and the energy needed for a pump to rotate the water is less.
The solar energy other than that falls over the solar panels warms up the air there. As it composes the vertical temperature distribution, we can expect quite high temperatures near the ceiling. An air duct intake is placed there and the hot air is sent to the distribution air duct under the basement ceiling. The air moves up to the living space and comes back to the solar room, while the heat is stored in the house. This is thermo-siphoning through air. With the two improvements winter should be warmer.
The formulation will be given in Chapter 2 or 5. If this system is solved and connected with the indoor thermal behaviour, we can improve the usage of thermo-siphoning.

A sleeping chamber in the basement
The annual temperature change in the basement is from 12.5 to 16 deg while a human being produces 100 to 150w. If a small thermal insulated chamber is assembled, it could be turned into a bedroom. We must not forget to at least have air ventilation holes. Thermal-insulation walls can be done with wine cask boxes filled with dry grass and connected with rice straw.

Heating with solar energy absorption by porous materials
The solar energy absorption of stainless wool is unexpectedly large as was mentioned in the section about direct solar radiation collection. Black pipes are placed not too deeply in the layer and the inside water is connected to a hot water cylinder and stores solar energy as shown in Fig.1-1-37.

Fig.1-1-37 Solar energy store with the solar panel using stainless wool.

The heat can be used during the winter night too. The system must be sufficiently thermally insulated and the front glass pane adequately resistive against high temperatures. If it tracks the sun, maybe manually, much more heat will be obtained. The negative radiation in the night is large on a fine winter day and should be avoided by covering. The systems would supplement each other. Except for the heat exchange part this has the same mechanism as the solar panels.

Electrical generation with the temperature difference in the house
It may be possible to use the temperature difference in the house to produce electricity using the heat pump and turbine principle. Temperatures are from 12deg in the basement to 30deg in the solar room in winter and from 16deg to 50deg in summer.
Outside bath heated by burning Kikuyu
Kikuyu that was brought in from Africa has very active photosynthesis. A book says that its efficiency of photosynthesis is 8.1% compared to 4.7 to 4.8% for all other grasses, and kikuyu easily covers half of the North Island. It was imported about 50 years ago and from this we can imagine how energetic it is. If nothing is done, the North Island could be covered with this grass and the land could not be used for other than stock farming. We quite like the idea of changing a disadvantage to an advantage by finding a good use for kikuyu – for example it could be used as fuel. While not an urgent project it would be interesting to build a shed for a bath on the slope, where Kikuyu could be burnt to top up the water temperature warmed by solar energy. It will be called Kiku (chrysanthemum) yu (bath) from the sound of the grass. It will be nice to feel relaxed, review the day and think of tomorrow. We must however consider how much additional energy is needed to harvest the grass.

Resume of the section
A variety of items for solar energy use were mentioned in the details for house design. They are classified as follows;

※ Direct collection of solar energy
1 Solar oven
2 Solar cooker
3 Collection by the two dimensional (cylindrical) reflector
4 Energy collection of the sky radiation
5 Porous material uses for solar energy collection
6 Hot water by solar panels
7 Electricity generation by a Sterling engine

※ Solar energy collection through plants
8 Coppicing for firewood and charcoal
9 Methane generations by the Ozeki septic tank
10 Solar energy and Kikuyu burning for bathing

※ Energy collection through natural phenomena
11 Windmills electricity generation
12 Ground heat use

For cooking, mainly items 1, 2, 8 and 11 (only during strong winds) will be used. Coppicing (8) is especially handy for energy storage. 9 will be used for triggering charcoal, but can be used for cooking with the contribution of animals, e.g., chickens and sheep. It saves a lot of energy to have raw food meals and this also does not kill the enzymes in the food.
Hot water from the solar panel 1.8m x 2.4m wide is enough to enable a person to have showers, do dishes and washing through almost the whole year. If dead trees, fallen leaves, Kikuyu etc are burnt ina fire place with a wetback, the double area of the solar panels is enough to supply hot water for a four member family.
If 3 and 7 are used successfully, their electricity can be added to the batteries. The top priority of the electricity is for a PC in order to have communication. A small refrigerator and lights can be used too. While quite an amount of food can be stored in the basement and crops can stay in the garden as long as possible, a small refrigerator is also necessary.
For heating the house, 6 and 12 are necessary. The use of the solar energy obtained in the solar room should be circulated using thermo-siphoning through water and air as mentioned before. The inside eastern wall will be cobbed to allow less heat loss in winter after checking by calculation. Item 10 is for relaxation and is not a necessity.

In such a way, we need to see solar energy from a broader angle and viewpoint. Then, grasping the seasonal change of each obtainable energy source and knowing the total amount through the year, we should plan our practical energy use pattern with reference to this. We have to properly align solar energy with daily demand, and if it is not enough, use other possible energy types available at the time to cover the shortage. For that purpose, we need to store each energy type. Batteries, a gas container, heat storage in water and/or walls, storage in the ground, a tank for rain water, firewood and charcoal etc, all are delay systems, and should be well planned and applied.

1-2) House designing and planning
The most important starting point for living sustainably is to observe and learn at the site: landform, geology, the climate through a year (wind direction and velocity, fine, cloudy and rainy days, water level change etc). Then after researching the site conditions, careful consideration should be made on how each detail shown in 1-1) should be used in a house design and plan. Thermal conditions and planning with the sun in mind should be the very first priority. Here we just point out that it is very important to start with this in the planning stages and the main strategy for thermal conditioning will be developed in Chapter 2.
If a house is thought of as one system, thermal conditions are solvable by linking two equations for heat balance and air movement with the one for thermal transfer through the enclosure. Using this technique, a comfortable thermal condition plan can be realized in the house after taking into account the house direction, the design of eaves, the dimensions of doors and windows, thermal treatments at the boundaries and so on. This is the most active use of the sun. A computer program to do this was made by one of my students, Dr. Hirotaka Azumi (a temporary lecturer at Sohai College in Osaka). In a comparison between the measured results and the calculated results given earlier, the calculated one follows the measured one quite well, having a largest discrepancy of 1.5 degrees which is explainable by human disturbances. The program is ready for practical use and more details are given in chapter 2.
Furthermore, environmental planning is also important to create a comfortable indoor climate. The synthesized evaluation for this will also be provided in Chapter 2.
(2) House construction with local nature-friendly materials

Every place in the world has their own locally developed and specific ways for housing and living. These are the results of their ancestors’ creations from long past experience and communication with nature. You could say they are a gift from nature. Before mass production was introduced, these ways were passed from generation to generation. From here on we will call this 'vernacular'.
There are so many examples of this in Japan. Rice paddies in curving terraces are a great infrastructure which was obtained after many years trial and error, learning from the direction of the sun, the wind direction in different seasons, water supply and drainage and so on. Crops are of course for food and stalks can be used for a rice straw rope, a pair of grass sandals, 'susa' binding in a clay wall, a sweeper, even thatching and so on. 'Shoji' and 'fusuma' sliding doors are elaborate works from our ancestors. They are the reflection of our old saying, "A house should be built thinking of the summer climate".
It is a great pity that many of these things are fading. We have to look back once again and connect old treasures to a sustainable life with scientific understanding.

2-1) Thatched roof
Thatched houses are widely seen throughout the world and are a typically vernacular form of construction. A variety of materials are used such as local grass, crop by-products, even seaweed. For the purpose of thatching, grass must be hollow with a strong straw wall, for instance 'susuki'(zebra grass), water reed, rice straw, wheat straw, tall fescue etc. Ways of thatching are basically similar, but differ depending on local conditions such as rainfall, snowfall, how the wind blows or local topography. They thatched learning and talking to nature. If birds come, flowers bloom, or moss grows on the thatched roof, this depends on the thatching material, the local climate, the slope of the roof etc.
Such a refined craft is fading in the strong wave of industrialization and it breathes very feebly. In addition, thatching material is difficult to procure. The common spaces to grow 'susuki' in Japanese villages are vanishing and their storages for years to thatch or renovate a roof are fewer and fewer. This sort of thing is an important subject to do further research on to support a sustainable way of living.

2-1-1) Thatching process
Usually thatching is stitched in and out and tied down over a purlin from the bottom to the top as shown in Fig.1-2-1. At the experimental house, it was done over the plywood roof and our German thatcher, Norbert Kleinschmidt in Nelson, had a hard time. A few photo snaps of his thatching are shown in Fig.1-2-2.

Fig.1-2-1 Basic method for thatching.

Fig.1-2-2 A few photo snaps of thatching.

2-1-2) Maintenance of the thatched roof
The following is an extract from my diary. When Norbert first came to do renovations was three years after he thatched the roof. He could not spend much time and it was not a large renovation.
After that, possums and birds damaged the roof and I did a bit of mending, but I could not do much because I could not get materials. Seven years after his thatching, he came over for the first major renovation. We went out to get thatching material in the form of bulrushes before he came. Through the local paper (“The Bugle”) we placed notices asking where we could get the grass. We got a few responses and went to two of them to collect bulrush with a few helpers. For me this was the first time to collect it directly myself. It was unexpectedly hard work. I could not keep working over the space of a week. Thatching is a wonderful trade but it is hard work to collect just the base material. The cut bulrush was dried in the greenhouse and thought to be enough of an amount for the renovation. But Norbert needed all we had collected just for the lower half of the renovation. In the meantime, I had informed the local newspaper that he would perform and also explain the renovation. We got about 15 people to a meeting and they were quite interested in what we were doing.
We discussed the second slope of the roof and decided to change it to a shingled roof because of the shortage of bulrush. Norbert came back and started to remove the thatch from the upper part, selecting good sections for later use on the lower slope. The top of the bulrush was damaged to about 5cm, but the rest was fresh enough to be reused. I cut the top with a special cutter, and the fresh parts were bundled and kept in the greenhouse, later they were moved to the attic.

There are two ways to renovate. If a hole is large and there is space under the wire to tie down, long bulrushes can be inserted tightly. If a hole is small and bulrushes still remain under the wire, short bulrushes which are cut to the proper length are hit into them with a wooden plate hammer. In other words, the additional length is inserted into the remaining bulrushes. If they are tight and wide, the inserted additional length must be tied down too. In the middle of a long wire, a wood screw is tied. The length of the double wires is the thickness of a thatch. It is screwed on the purlin. A half split bamboo is tied down over the additional thatch with the wires.
A bird net was put up in February 2002. Not many people noticed it even at a close distance, and birds look like they have given up nesting in the thatch at least. Norbert left me a chair to be stuck in the thatch, under which there are two pins of a thin iron plate, and a tapping hammer of a wooden plate as shown in Fig.1-2-3. In the figure, the set of his tools for thatching are shown as well. Good material which is hollow and has a strong wall is necessary. Water reed is such a material, but it is considered noxious
in NZ.

Fig.1-2-3 Norbert's thatching tools in the left and a few tools for mending.

One possibility is if rice straw grows well and long and another is to use long wheat straw. Recently, I was told that there is a native grass called Kuta which grows two meters tall like a water reed in a lake. I want to go and see it.
2-1-3) Thatched houses in the world
Shirakawa-go village is well known not only in Japan but in the world as a global heritage area. There a wonderful collection of thatched houses at Hattori-ryokuchi ethnic museum. Some photos from my collection are shown in Fig.1-2-4.


A Japanese house after late Prof. Horie’s

Thatch renovation at Shirakawa-go (1) by mate Kishimoto
Thatch renovation at Shirakawa-go (2) after a school
An East-European house after late Prof. Horie
Cuddy of David Studholme's, Waimate

An East-European house after late Prof. Horie
A Danish house thatched by seaweed Prof. Marumo, Kansai Univ.

Fig.1-2-4 Thatched houses in the world.

2-2)Rain water for daily household use
There is no concern about acid rain in NZ as of now. Rainwater is drunk in remote areas. Our ground rain water tank is made of reinforced concrete with a height of ca.2m, ca.2.5m in diameter and a capacity of 15,000 litres. Inside the tank, no light comes in, and germs do not grow so it is clean. Fig.1-2-5 shows the present water supply system from the ground tank to the house. We drink the water once boiled, but if we could find a suitable filter to kill bacteria and viruses, we could save that energy. We have to study the sterilization effect of bamboo charcoal. A hand or foot pump will be used to lift the water to the header tank. The overflow at the top of the ground rain water tank discharges the floating organic mix. If we have a U-shaped pipe to see the inside water level, it would be handy.

Fig.1-2-5 Rain water supply system.

At the entrance to the water tank, a sludge trap is connected as shown in Fig.1-2-6.

Fig.1-2-6 Sludge trap to eliminate large rubbish like tree leaves.

If rain water from the spouts includes tree leaves and other rubbish, first they drop into the big cylinder where a ball floats, and rubbish is stopped by the floating ball. Then only the clear part above the ball goes into the water tank. These days we drink the water directly from the tap – we carefully observe the quality and there has been no problem fortunately. I will pump up the necessary water for daily use to the header tank, but at this stage I rely on electrical power.

2-3) Cobbed walls
Japanese clay walls are typically vernacular. I gave a talk at a small international conference held at the Dept of Architecture, Auckland University and needed to learn about it quickly. Here the manuscript 'Vernacular aspects of Japanese clay walls' is reprinted.
This report looks back at the history of Japanese clay walls especially from the vernacular point of view and how the technique developed by the climate and culture can be applicable in the present day and harmonizing with nature. It has been said that a Japanese house must be designed and built for summer. The Japanese summer is very hot and humid; the environment must be thought of more than any other factor. Accordingly, air flow is very important to decrease discomfort as is the intercept of the sun by deep eaves.In the past, a house structure was mainly of timber frames and a wall was only a partition or a curtain wall. In other words, the frames supported the entire load. While many Western walls had a role in supporting loads, Japanese ones were not counted on to give this support. However, one thing that we must not forget is that Japan gets a lot of earthquakes. For that reason a komai mesh in the clay wall is unavoidable.
An old example 1300 years ago is found in the Horyu-ji temple's clay wall. As the base of plastering, a lath called 'komai' was woven. In olden times, the lath was knitted with thin wooden blanches or split branches and stitched with rice straw ropes. Over the lath, earth or clay mixture with cut grass 'susa' was plastered as a first coat. The 'susa' was used to link dry cracked clay pieces. Rice straw, hemp or paper etc was used for 'susa'. For rendering or the first coat, very clayish earth was mixed with 'susa' of rice straws 15cm long. Less clayish earth was sieved and used for the middle coat. The next coat was created with 'susa' of rice straws ca 3cm long. The finishing coat was white earth or slaked lime in the Heian era (8th to 12th cent), and later, slaked lime finish was applied to make the white surfaces of castles and mud-walled storehouses.
Split bamboo started to be used for 'komai' in the middle of the Heian era. Bamboo 'komai' were used in most of the clay walls in the Momoyama era (16th cent). 'komai' has a basic role to prevent cracks and to be clung to by dry clay, but it has to be noted that it worked to hold the wall against earthquakes as well. The plaster trade was established in the Momoyama era, but its origin went back to the Nara era (8th cent). The technique to mix paper into slaked lime was a unique Japanese way. Slaked lime, Ca (OH) 2 was obtained from calcium oxide, CaO by mixing water.

As castle walls had to be solid and fire-resistant against enemy attacks, they needed to be finished to be thick enough to do this. Walls of the Himeji castle were plastered 49cm thick.
Its structure is basically the same as in Fig.1-2-8, there 'komai' provided the essential groundwork too. The first coat plastering was given over to 'komai' and to get a good assimilation of later plaster, rice straw ropes of 30cm were hung. Clay balls mixed with 'susa' were twisted into them by hand making a thick wall foundation. At the Hikone castle, 'komai' were doubled and pebbles were filled in between, then the rear side of 'komai' could not be plastered by hand. As the surface of a horizontal plane had to be plastered upwards, bamboo sticks rolled with rice straw ropes were nailed to the plane to create a good bond with the first coat. Its thickness naturally became thinner. Then the middle coat was done and finished with slaked lime. In such a way, the whole surface of the Himeji castle was plastered in white and it is called the White Heron castle.

Fig.1-2-7 Clay wall of the Himeji castle.

In the beginning slaked lime was mixed with rice porridge, but rice was a precious food and an alternative was needed. Ground shells were also used together with slaked lime. A seaweed (Gloioperitis) was boiled and used as glue. The glue of the seaweed was used with the slaked lime too, and it was used for the coating of common houses since around 1600. Before then seaweed was only a food so it could be said that this was a technical innovation. It is said that oil was mixed in to improve workability. The glue improved adhesion and held moisture. Also it made the mixture stickier and improved workability. This technique was applied to a mud-storehouse. The main house was built with wood and burnt easily. A solid store house was needed. There they applied the same technique as for the thick wall construction of a castle.
After constructing 25 castles around 1609, many plasterers lost their jobs and moved to work onbuildings and mud-storehouses using seaweed glue and a lime of ground roasted shells, because they could not use the rice glue due to the extravagance prohibition law that was in effect.
Ventilation was made as small as possible and the then skilled plastering made strong doors and windows which were multi-layered and air tight. During World War II, houses mortared on the lath and wooden houses were completely burnt down by bombing, but mud-storehouses remained here and there.
Such structures have great heat storage and are reflective against solar radiation. They can be used for indoor environment control depending on the local climate. If 'komai' is doubled with an air gap in between and plastered from both sides, it lessens the heat flow.

The partition of a thin wall started to use bamboo for a 'komai' net and had structural stiffness. A tea ceremony room was build very modestly using a tree as it was for columns and clay walls. 'susa' was shown on the finish to make the texture enjoyable and create a modest expression. And 'komai' was partly left open as a window. Unfortunately, the modest expression turned to an ornate one later on. In the Edo era (17th to 19th cent), there was legislation against luxury and extravagance, and there was an influence to create beauty in modestness. It seems that politics some times affects even construction methods!
It is just a partition but it occupies a large area in a house. It was necessary to be artistic and using a variety of earth, the most sophisticated skills were shown in the plastering technique. Katsura-rikyu Palace left a wonderful creation as a German Architect Bruno Taut noted. The plastered surface was finished with slaked lime mixed with paper fibre 'susa', and afterwards its surface was scratched, in a way called 'parari' and with a coarse but fine finish. This technique has disappeared. The climate and the local building materials created different constructions in Edo (present Tokyo) and Kyoto. This is the exquisiteness and charm of vernacular methods.

Cobbing (plastering) process at the Experimental House
During the excavation for the basement, the soil was left for cobbing from three layers of soil. David Studholme and Ron Hutt from Waimate in South Island tested the soil to determine which layer of soil was the best for cobbing. Cobbing was done over the 2x4 structure from both sides. Our traditional 'komai' lath was knitted with split bamboo, but we found that it took so much time that it was decided to knit only the eastern inside wall. Actually two of my students did this and it took a good month for the area of 8m x 9m to be completed. The other area was made with stapled wooden battens. The first coat was expected to be done in the Japanese way, with the mixture of clay and 'susa'. During discussions sand was already mixed. The first coat needed quite a period to dry but it turned out to be impossible to do this for further layers. The later two layers had cement mixed in. As a result the cobbing was not done with a consensus which was my mistake.

The basis of Japanese cobbing is firstly a 'komai' lath, which is knitted split bamboos and stitched with rice straw ropes, and secondly, to cob layers over the keys of cracks. 'komai's bending strength works well against earthquakes and 'susa' is clung to by the clay to hold the wall when it is dry. The first coat adds the mix of clay and 'susa' and one waits until it is dry (see Fig.1-2-8). The clay becomes hard and gets a lot of cracks, but the 'susa' holds each other. On the rear side of 'komai' a lot of keys come out and the surface of the first coat gets a lot of cracks. These are the keys for the second coat. This is mixed with sand and the surface cracks become finer. These are the keys for the next coat. The finishing coat is the mixture of clay, fine fibre, sand and seaweed glue (or rice glue).

If the finishing coat is mixed with cement, the clay part wants to get rid of water and the cement part wants to get water and crystallize with it. They should be slowly and carefully dried, otherwise the surface will get cracks. At Kaiwaka, because it was plastered over the 2 x 4 structure, a large air gap was created to be used for thermal insulation. A variety of materials were used as fillings. Wadded news paper, wadded plastic, bulrush, fibreglass, and fleece were filled in the air gap to compare the thermal behaviour there with the wall of air only. The heat flow and thermal conductivity coefficient there will be measured. The windows and doors are triple glazed in different styles. Later, the heat flow for each style will be measured. When the thermal conductivity of bulrushes filled in a 12cm width of the 2 x 4 wall is estimated at 0.063, the overall coefficient of heat transfer is 0.43 which compares equivalently with that of a commercial modern wall. It tells us that with a traditional cobbed structure thermal comfort can be established.

Fig.1-2-8 Plastering a clay wall with 'komai' lath.

Fig.1-2-9 Plastering the second coat over the first one.
Finishing coat with mixture of rice gruel at the dark section.

As shown in Fig.1-2-9 first and second coats were tried, but unfortunately we could not finish the discussion and reach consensus. Recently, we have a bad influence upon the Eastern and Western walls. Japanese cobbing uses the hardness of dry clay like concrete, but in NZ they mix a bit of cement in and clay must include sand. When the original selection was made I believe sandy clay was chosen because of that. In terms of nature-friendliness, an adobe structure is wonderful and widely built throughout the world. However, lack of earthquake resistance is a point against it. Bamboo tends to be forgotten as a building material. It can be used to reinforce clay structures. It can be bent while it grows. Its round shape can be squared if forced by four panels and the square bamboo can then be a beam.
Meantime, we looked for a seaweed gloioperitis which is used as glue for the Japanese clay wall, but we could not find it in NZ. This felt strange, because the ocean between NZ and Japan is connected. Indeed, some familiar Japanese fish can not be found in NZ and NZ has a lot of fish which we don't have in Japan. Even though the ocean is connected, apart from migratory fish, fish species are local after all.
As a conclusion I believe that traditional Japanese clay construction is very suitable for NZ which experiences similar earthquakes. Going forward I want to redo the walls in the Japanese way to create a good example.
(3) Cleansing of exhausts and drained water from daily activity.

The best prevention of environmental pollution is to do it at the source, nothing else is possible. If a pollutant is known its processing is easily found. On the other hand, if processing is tried after things are mixed, it may be necessary to choose an easy way, such as burning, which produces secondary contamination. The pollution from a family house must be done following the principle of cleaning it at the source. Human activity must not contaminate the outside environment. The pollutants created by human activity are excretions, soapy water from a shower and doing dishes, carbon dioxide by cooking and heating etc. If all pollutants are processed well and returned to nature, human activity does not cause any harm to the earth and its living system is closed.

3-1) Bio gasification of organic wastes
The Ozeki septic tank is a wonderful invention as was explained in 1-1-1). It processes at the source excretions, garbage etc to biogas, and a large infrastructure such as a sewage system is not necessary. It does not need any energy to warm the liquid. Consequently, the energy that is used to burn excretions is not needed. This is just an ideal system where natural processing is applied. In NZ, cow manure at milking is spread with water and reaches a creek and then is carried to the ocean. A place where many people gather, such as an airport, produces a lot of garbage and excretion during a flight. Auckland airport gets 7 tons of this refuse a day which is burnt at the corner - I hope that Ozeki septic tanks could be used there. The biogas turns to carbon dioxide when it is burnt. Its processing is described in the following section.

3-2) Cleansing of drained water and carbon dioxide in the green house
In the area next to the Experimental House, there is a greenhouse that is 4.5m wide and 10m long. It has an agitation pond and three cleansing ponds, with an air duct from the kitchen. It sends the burnt gas in the kitchen with an electric fan over the plants in the greenhouse, cooling it down on the way. Photosynthesis by the plants analyses and absorbs the ingredients of grey water and change carbon dioxide into oxygen. Please refer to the early stage plan and results in "Nature-friendly experimental house - Third report from Kaiwaka - Clarification of carbon dioxide after cooking and drained water by the photosynthesis of plants in the green house" Journal of the Japanese solar energy, vol.22, No.4, p34-37(1996).
In the beginning, it was planned to have a short experiment with ponds of plywood frames, because the alkalinity of concrete does not work well for experimental purposes. Recently, the ponds were changed to use reinforced concrete walls so as not to have any leakage and a variety of water grass have been tried. The following is a report on the present situation.

The discharge and evacuation wastes of a household must be returned after cleansing. If each home makes the effort, an infrastructure may not be necessary. Excrement is processed into biogas and the gas is used for cooking. The rest of pollutants, i.e. carbon dioxide after cooking, drained soap water from sinks, a shower room, a washing machine and kitchen sinks, so called grey water, must be cleansed. In this project we rely for cleansing on the photosynthesis of plants. Carbon dioxide after cooking is guided through an air duct to the greenhouse. Grey water is collected in the agitation pond and sent to the next cleansing ponds of zig zag channelling where plants grow. There are a few systems like a wet land system which process with plants in a pond or a greenhouse. Most of them treat excrement and grey water together. Furthermore, there is no system that treats the exhaust gas from cooking in the same greenhouse.

1) Cleansing ponds in the greenhouse
Three cleansing ponds that come after an agitation pond were constructed in the greenhouse; their plan and section are shown in Fig.1-3-1. The three ponds have sand layers with different depths and zig zag channels for the water to run a longer course. The sand layer is expected to have bacterial activity, and the longer the grey water runs, the cleaner it becomes through the plants photosynthesis. The newly constructed concrete ponds are shown in Fig.1-3-2.

Fig.1-3-1 The plan and section of an agitation pond and three cleansing ponds.

Agitation pond and the air duct
The first cleansing pond with rice growing
The second cleansing pond with floating weed
The third pond with cleansed water
Air duct from the kitchen to the greenhouse

Fig.1-3-2 An agitation pond and three cleansing ponds in the greenhouse

In addition, an air duct with an electrical fan takes the carbon dioxide created after cooking into the greenhouse. The gas is cooled by the outside air in the meantime and falls over the plants (see Fig.1-3-2). The carbon dioxide is heavier than air at the same temperature.

As the water after a shower still retains a higher temperature, it bypasses a thermally insulated pond where the heat is used for the fermentation of dough and then goes to the agitation pond as well. The whole drained grey water is gathered in the agitation pond before being moved to the first pond.
When the project was planned we thought to do the following:bulrushes for thatch roof renovation in the first pond, water hyacinths for biogas generation with active photosynthesis in the second pond and watercress for food in the third pond. However, the period of stay at the House was limited to only 4 months a year at this stage and water use was unexpectedly not great.
In summer especially even the first pond was not filled with water because of active evaporation. We were told water hyacinths were noxious because of their energetic propagation. As a result, the second and third ponds were not used. In addition leakage was noticed and it was decided to change them to concrete ones. The existing plywood was used as the outside frame and concreted about 8cm thick with the reinforcement of iron bars. The first pond is ca 1m deep. A concrete panel 2cm thick was made with a 2cm mesh in the middle, to be a water guide for the zig zag channel. River sand was placed ca 79cm deep. The level difference between the inlet and exit was less than 5mm. Water was filled to a 10cm depth above the sand surface. The second and third ponds were made with concrete too and were to get gradually deeper. In such a way, if cleansing ponds are in a greenhouse, the grey water will not mix with rain water and can accelerate plant photosynthesis because of the warmer climate. This can be considered a part of solar energy use.
2) Plant growth in the first pond
Bulrush was used for thatching the roof. About ten stocks were planted in the first pond on 30/08/94 with the idea of using them for later renovation of the roof. Spring was chosen for the transplantation. However, other weeds started to grow as well. Some time later, I got a few stocks of water reed from Norbert and planted them in the first pond. When he brought the seeds to NZ from Europe, he received permission from the quarantine office, but we were later told they are considered noxious too. We noticed leakage in the first pond and decided to line them with concrete. When we turned over the sand under the peacefully coexisting weeds there was a layer of hairy roots from water reeds that was 30cm deep. It might have given nutrients to them. A further surprise was that under the layer in the sand thick roots of water reeds ran left to right up and down showing a dominant strength of growth. This power would easily overcome other water grasses in the same way as kikuyu does to other grasses. We then understood the reason why they are treated as noxious and burnt all the roots. Once we wanted to have enough water reeds to thatch the roof and planted a few seedlings for this purpose in the bottom field, but they were covered with weed mats.

3) The change to concrete ponds
The concreting started in February 2003 and was finally over in the end of September. Plywood was used for the outside frame, ready made iron meshes were placed in the middle and concreting was done between a movable corner for the inside frame and the outside frame. A separation panel for the zig zag channelling was also made with concrete with a 2cm iron mesh in the middle. The thickness of the concrete walls is somewhat not even due to our workmanship and the final dimensions are 6 to 8cm inside those of the drawings in Fig.1-3-1. To prevent leakage the surface was painted. Sand was filled as in Fig.1-3-1 reusing used sand as much as possible. The sand layer is expected to have bacterial activity and also creates a filtering effect. Once we were told that the planned grass was noxious we tried some other kinds of grass but they still need further investigation. In summer, the sun is too strong for them and a shade screen of 30% cut was stretched under the ceiling of the greenhouse as protection.
In June, 2003, a few old rice roots from the latest harvest were transplanted to the first pond. The grass grew healthily with clear green shoots and looked to be growing well in the grey water. It also grew grains earlier than the ones that were in the rice paddy – their tops were already bowing by January 2004 which was early. About ten seedlings were transplanted from the seed bed at the end of the previous year, and they started to produce grains as well. Azolla was put into the first pond and covered the latter half of the pond. It looks like it is moving up towards the mouth but more observation of this is necessary. However, the grains were not well developed. This might be because the pond was always filled with water or because the energy was not sent to the grains, or maybe because in the night the greenhouse gets colder and aphids attacked the grains because of the still warm air which they like.

In the second pond, azolla and water cress exist but duck weeds are dominant. Whatever is growing, the water at the exit seems already quite clear.
The third pond has two water lilies, penny warts, oxygen grass and eel grass. As the water level decreased quickly even with the shade screen, another screen was added over the pond. The decrease was thought to be caused by evaporation and photosynthesis. The white surface inside had a lot of yellowish algae and the water looked to be not that clean, but when it was scooped out by hand, it looked very clean. Of course, final judgement should be made after water tests. Recent observation concluded that the decrease of water was caused by leakage at the joints of the concrete. We are going to paint there.
On the 26th of November 2005, we had hail stones fall in our village area exclusively. Large ones in this storm were as big as a golf ball. Locals who have lived here for a long time said that they had never experienced this kind of unusual climate. The ground was covered in white and the bird nets over the rice paddy could not let the hail through and were broken at three stitched joints. The greenhouse roof also got hit and 6 glass panes were broken.

4) Summary
It is evident by inspection alone that the water in the third pond is much cleansed. It runs through zig zag channels to three differently designed ponds. While it does this plants and bacteria in the sand layers analyse and absorb ingredients in the grey water. The additional carbon dioxide, the warmer climate in the greenhouse from the mild local climate make the plants grow well and have active photosynthesis. For better cleansing we get rid of any floating grass from time to time. It will be interesting to see the effect if we make the width of channelling panels narrower, thus letting the water run further. By investigating the air density measurements we should be able to find how much carbon dioxide is changed to oxygen through photosynthesis. It should also be checked by water testing how much nitrogen, phosphorus and other ingredients in the grey water are absorbed and eliminated through the ponds.
The most appropriate and best species for the third pond could be a future subject of investigation. We will visit a few lakes to see floating grasses. Evaporation through high temperatures can be counted as cleansing. The active growth of the plants is the absorption and storage of solar energy and could be used as an energy source. A part of this could be given to the septic tank, part could be compost, and part could be food etc. It is interesting to look at a plant from a variety of angles. If a greenhouse is to be used just for cleansing the grey water and carbon dioxide from family use, it could be smaller than at the Experimental House.
The water in the agitation pond looks to be within the limits for frogs to be able to live in. They eat mosquito larvae and as a result not many mosquitos are seen in the greenhouse. They have a new ecosystem there. The other ponds offer more comfortable environments to live and some forget to hibernate. It is meaningful to use a greenhouse as a solar energy collector but there is a question over how negative radiation in the night could be treated. It might be worth investigating how the environment would be changed and used if a cover is used for thermal insulation and to intercept the radiation.
In such a way, by treating the carbon dioxide and grey water, I believe the harm to the environment is dramatically decreased. I want to emphasize again here that a pollutant must be treated and processed cleanly at the source. This should be the hard and fast rule for any contamination. Nature lets us live and we must not fiddle and meddle with it. Under the sun, each one's life should not put a load on nature – it should be a closed system. Then nature is welcoming, flowers, birds, insects, small animals etc come by themselves and we find delight and joy.
(4) Self-sufficiency based on organic farming

On the basis of (1) to (3), if we produce our own foods based on organic farming, we need not earn money from others, and then we are liberated and can become free.With this, we can proceed to joy and happiness.
We are surrounded by a world full of unnatural human products; chemical fertilizers, herbicides, pesticides, genetic engineering etc. We need to strictly protect ourselves in order to 'survive'.
The farming at the Experimental House is not one of large scale production. Depending on one's taste and given time, we can properly plan to efficiently get necessary nutrients and then we need not work very hard. In my case, rice is the primary crop. If brown rice is eaten, a variety of nutrients are included such as essential amino acids, vitamins, starch etc. I need not grow much of any other food. Soya beans are the important supplier of protein. Black sesame is necessary for anti-oxidization. I want to eat salad and vegetables in season. As animal protein egg is essential.
One of my friends said that agriculture goes well through experience. I think this is very true. After failures one learns the way and the joy in success is great. However, as time is limited, without the exchange of one's experiences and information, proper growth will be hard to get.
Japan has, say 2000 years in its history of rice growing, which means 2,000 times of trial and error. However, if 2,000 people cooperate and analyse their results with knowledge and information, a good method can be worked out in a short period and a local place gets the best way to grow for their specific conditions. This applies not only for growing rice, but for all other crops as well. As this project is diverse, I could not spend much time on agriculture, but by slowly getting experiences and establishing a daily work routine, I have enjoyed growing crops.

The soil in the hill is clay and it is very difficult for plants to root deep into this. The clay can become hard like concrete and provides little nutrients for plants. The bottom part is most fertile because sand and nutrients were deposited there by the creek in front. The soil on the foot of the hill which faces south is clayish, but softer than the one on the hill. We have carried fertile soil to the hill top as time has permitted. A vegetable garden should be close to the kitchen. A vegetable garden was started on the west side of the house measuring about 70m2. However, the soil is of two extremes, hard or pulpy and difficult to work.
Further, kikuyu grass which was brought in from Africa grows very quickly and reaches sometimes to a depth of 40cm. It took quite a while to get rid of the kikuyu. While I was commuting between both countries I could not do much to it. Kikuyu grass is one that is considered an African grass in a book on photosynthesis. It says that most grass
Kazuo Shibata; "Light and plants: energy and entropy at photosynthesis", Baihu-kan, 1982.
has a photosynthesis efficiency of 4.7 to 4.8%, but kikuyu has 8.1%. Any other grass can not supplant it. If it is together with other grasses in an area it takes over completely. Indeed, in the past 50 years since it was introduced to NZ, meadows and lands have been almost covered by it in Northland. It keeps growing through the year. Farmers need not have any animal barns as they can just provide hay from the meadow (grown in summer). While it may be a good grass for stock purposes for other agriculture it is very troublesome. At the Experimental House considerable time was needed to suppress it. Various things were tried - turning kikuyu over with a hoe and pulling it thoroughly, or covering it with a wide weed mat. As growth appears to be suppressed under pine trees, putting pine leaves under the weed mat was tried. The introduction of this grass is one of the worst examples of inconsiderate human thought.

Since I resigned from Kansai University at the age of 60, I have worked steadily with limited time for 8 years, but I still have to improve the soil further. The only way to do this is to mix compost in. Kikuyu can be good compost. Although it was only for seven months, I had a sheep at one stage and added his manure. He died of facial eczema leaving me with wonderful memories.
Vegetable gardens are dotted through the property. One of 70m2 is on the hill, the second one of 30m2 is on the southern foot of the hill and called the middle island, and the third one of 30m2 is on the bottom next to the rice paddy and called the lower island. The latter two were places where kikuyu grass grew. Each vegetable garden has a different soil quality and gives me an interesting comparison.

The rice paddy of 131m2 produced 60kg in 2001, 80kg in 2002, 48kg in 2003, 78kg in 2004, 66kg in 2005, and 38 in 2006. The amount harvested is affected not only by the climate of the year, but also shows a biannual behaviour pattern (except for 2006). The unexpected harvest of 2006 is discussed in Chapter 5. I am pretty sure that NZ can grow rice well. In terms of efficient land use, I don’t need to use any other crop while the paddy is out of rice growth. All the old roots were left in autumn 2005 after the harvest, covered with black plastic sheets to suppress couch grass. However the 2006 year harvest was very bad. I think this was caused by the covering sheets not allowing enough sun light and oxygen to reach the roots in spring. This result is discussed in the chapter 2.
A vegetable garden for a four member family needs at least 100m2 of land. My aim is that to always have something with the proper nutrient balance growing throughout the year. I grow two kinds of soybeans, one is a NZ variety and another is from the edamame species. I have harvested these for three years. The edamame grows more and larger pods. A black sesame produces a sprout. Vegetables were sown a bit earlier in the middle of September and many of them flowered. Shifts in sowing should be done.

Mini knowledge primer for fertilizers: 16 elements are necessary. C, H2, O2 are taken from air and the ground. The other 13 are from soil. N2 for leaves, phosphoric acid for fruits and plenty of potassium for the roots. Calcium for root tops, magnesium for chlorophyll and sulphur for protein must be added appropriately. Seven trace elements are required - iron, manganese, zinc, copper, boron, molybdenum and chlorine.
The liquid in the last section of the Ozeki septic tank is composed of non-organic substances after all the organic matter is decomposed. It must include the above elements - especially the trace elements. It is said to having good soil gives a good environment for microbes. For farm work, some books in Japanese language, for instance, one by M. Fukuoka, one by G. Tokuno etc, were used for reference.

Recent harvest of crops

As of July 2005, the following crops are grown and harvested. See Fig.2-2-2 in chapter 2.
rice (Yukihikari from Hokkaido), potatoes (Maori, red and white), Kumara (sweet potato), buckwheat, soybeans (NZ, edamame): they are possible to grow from the middle of Oct. to the middle of Dec, broad beans, red beans, kidney beans, sweet corn.
endive, mibuna, mizuna, pak choi(2 species), kale, komatsuna, a variety of lettuces, cucumbers(three species), tomatoes(14 species), chicory, melon, water melon, broccoli, cauliflower, Brussels sprouts, Spinach beet, silver beet, spinach, zucchini, cabbage (green, purple), snow peas, pumpkin (2 species), Egg plant (2 species), leek, green pepper, Japanese pepper, okra, nira (garlic chive),
Beetroot, radish, daikon (2 species), turnip, burdock, carrots (3 species), onion, yacon, asparagus, Japanese shallot, Japanese taro, Japanese yam,
Hot chilli, shungiku, parsley, labiate,
Gourd, loofah.
Passionfruit, grapefruit, lemon, fig, apples (Fuji and Golden delicious), kiwi, cherry
plums (2 species), apricot, peach (yellow), mulberry, olive, strawberry, persimmon
chestnut, hazelnut, almond
Fruit and nut trees not yet harvested
nashi pear, citrons, macadamia, avocado, walnut etc

As listed above, quite a number of crops are harvested at the site and I continue to learn. Though I have to suppress kikuyu and improve the soil quality, if I plan and work better according to the season, the mild climate will help me. However the present crops alone give me rich nutrients and a healthy diet. Planning is important - when crops should be planted and harvested, and what quantities are necessary. Weeding must be done frequently, because weeds are so energetic. Using the smallest area required means less weeding is necessary. Potatoes continue to grow on and on and hinder planned work. I bought a few sackfuls of sheep manure from a boy scout. I also got manure from my sheep later on, but he died because of facial eczema. Chickens could be a replacement source. Some crops need their growing plans changed now to harvest them longer. When a new branch comes out between a stalk and an established branch, it should be taken off for tomatoes, egg plants, peppers etc. In order to make the stalk healthier, first fruit should also be removed. After a vegetable garden is established, I want to apply Fukuoka's natural farming with no cultivation and no fertilizer.

A few views of my vegetable gardens and rice paddy are given in figures.

The whole view of the rice paddy at harvest time
The water drained rice paddy is ready for harvest
The seed corner covered with black plastic sheet for suppressing couch grass The seedling corner covered with a black plastic sheet

Fig.1-4-1 Scenes of the rice paddy.

Upper vegetable garden 1
Upper vegetable garden 2
Golden delicious apples Kiwi fruits Olives

Fig.1-4-2 Sceneries of the vegetable garden and fruits trees.

About cooking and dishes

Now, the production of crops alone does not give you any food. Cooking is the next issue. In the beginning of summer 2003 with the help of a few young people we started concreting the ponds in the greenhouse. I cooked for them my brown rice and stir-fried the vegetables of the day. The latter dish was cooked only with pepper and salt as seasonings. Every dish used tomatoes and zucchinis, and it looks like the ratatouille from Province, South France. I call it Kaiwaka ratatouille of the day.
Though I have not yet produced food such as oil, salt and grapes for wine, I received a good confidence boost about food production as I was able to serve every day so many wonderful dishes to hungry young people. Oil will be squeezed from olives and black sesames, salt will be made from sea water being boiled in the solar cooker. The water left after crystallising salt will be used to fix the protein of soybeans into a tofu. fermentated soy beans, i.e. natto and brown rice with red beans are highly essential foods for me. They are said to be good against thrombosis and have many health benefits. I want to grow mushrooms and shitake mushrooms.
Cooking tools should be energy saving as well as able to cook well. I mentioned earlier a cooking tool which uses the thermal insulation of vacuum called Shuttle Chef, one which does not waste the flame heat giving a skirt around the pot called Hakase Nabe, and our handmade thermal insulation box with fleece. Avoiding Teflon treated frying pans, I got an enamel processed one made in France. Because it is heavy and keeps heat well after cooking, the taste is improved. If we look at daily cooking, we would be able to find a lot of areas to improve.
Dishes that I have learnt to make with ingredients grown at the Experimental House are:
tempura, vinegar pickles of sliced turnips and radishes, salad leaves of turnips and radish squeezed with salt, pickles of Japanese shallots, sukiyaki, fried rice, stir-fried vegetables, noodle soup, schnitzels of meat and fish, cucumber squeezed with salt, salted Chinese cabbage, baked potatoes and sweet potatoes by the solar oven and so on.
How to make tofu; soak 1 soybean in 3 water over night, crush it with a blender, and boil it for 5 to 6 minutes. Stir it so as not to burn on the bottom and get rid of foam. Keep at 70 degrees and mix in bittern to fix the protein. 9gr of bittern to 100cc of soy milk is what is needed.

Summary of this chapter

Collecting a variety of energy given by the sun, constructing a house of comfortable indoor climate using local materials, not contaminating the house surrounds in order to blend into nature, and being self-sufficient based on organic farming, we are able to use leisure time freely. Finally, one is liberated and becomes free. I have been doing my best to establish the sustainable way of living as soon as possible.

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