August 11, 2015


Biomass Energy Powered the Edo Period

Keywords: Newsletter Steady-State Economy 

JFS Newsletter No.155 (July 2015)

Photo: Rural Life in old Japan
Image by Okinawa Soba (Rob) Some Rights Reserved.

The interval of Japan's history between 1603 and 1867 is called the Edo Period. During this era, Japanese society established a unique and sustainable society that operated within the capacity of its domestic resources by properly using plant-based materials without depending on overseas imports including fossil fuels.

The novelist Eisuke Ishikawa, one of Japan's leading researchers on the Edo Period, delivered a keynote speech at the "Kanto Biomass Forum" in 2004 hosted by government-affiliated associations in the Kanto region. The theme of this forum was to consider biomass energy with a perspective spanning three generations -- encompassing Japanese traditional culture and future biomass use. This article will introduce Ishikawa's keynote speech with the permission from both Ishikawa and the Kanto Regional Agricultural Administration Office.

In Japan, it seems to me like this: on one pretext or another, Japanese people stopped following the daily habits that we now call "recycling" and "volunteering," using words borrowed from English. This gave rise to an array of problems, and so we imported the same ideas from overseas and started doing the same things again, using foreign words, as such things were formerly taken for granted and not conceptualized in the Japanese language.

On the other hand, the case of the imported word or idea of "biomass" is slightly different. It seems that the idea of biomass is perceived in Japan as directly analogous to our traditional recycle-oriented lifestyle.

We tend to say, "Let's go back to a recycle-based society," however, this will never be achieved in our current society.

This is because an enormous amount of energy - as much as about 120,000 kilocalories (kcal) - is now consumed per capita every day in Japan. About 100,000 kcal of this is generated from fossil fuels, which cannot be replenished once they are used. Since fossil fuels are necessary even for material recycling nowadays, it is completely impossible to do "true" recycling.

I call our current world a one-way civilization. Resources such as fossil fuels are consumed at a rapid rate while resource replenishment hardly ever occurs. What we call a "recycling-based society" is simply like spinning a top on a one-way conveyor belt.

In this context I think of Japanese society in the Edo Period as a society on a turntable. All the material resources flowed through the society in a cycle we can compare to a turntable spinning a record; it was a truly recycle-oriented society. The turntable revolved 360-degrees over the course of a year, because almost all materials in those days were biomass resources derived from plants.

I define "biomass" here as "biological resources, mostly plant-based materials."

Almost all commodities consumed in the Edo-Period lifestyle were made from fast-growing plants. Anything that wore out was disposed of or burned and the residue would decompose into water and carbon dioxide, which helped grow plants during the following year. This kind of cycle would not increase the volume of carbon dioxide in the atmosphere, while maintaining a stable annual material balance.

Of course, metal products, ceramics and other products not derived from plants were used in daily life. People used biomass resources such as charcoal to refine metal products and to fire ceramics. As long as plant materials are used properly and within certain parameters, they do not become depleted.

Photosynthesis made it possible to operate such a system. Carbon dioxide and water are taken up into plant tissues again and again using energy from sunlight.

The simplest example of biomass use in the Edo Period is rice cultivation. The population in the 1720s was about 30 to 31 million, of which 14 million people - nearly half - were engaged in growing rice. Wet-paddy rice cultivation is the most suitable agricultural practice given growing conditions in Japan. Compared to wheat production during the same period in Europe, wet-paddy rice cultivation in the late Edo Period (1751-1868) could produce enough food for about 10 times more people using the same sized area.

In these former times, people chose to grow rice varieties that would produce as much straw as possible, since rice straw has many uses.

After we eat rice, we produce excreta. In our present modern era, we process human excreta using enormous amounts of energy. However, people in the Edo Period sold human waste as fertilizer. Such fertilizer went back into the soil and never flowed into drainage systems. Therefore, the river water in Edo (present-day Tokyo & vicinity) and Osaka was clean enough to drink. Well water was used for daily housework such as washing clothes and house cleaning. People drank water from the rivers. This was exceptional because no other [urban] river in the world at that time could provide drinking water.

Thus, farm crops consumed in cities ended up as a source of fertilizer. For farmers, it can be said that cities functioned as a device for converting food into fertilizer.

As for rice straw, according to researchers, half of the straw produced was returned to farmlands as fertilizer in the form of compost or barnyard manure.

About 30 percent of straw was used for fuel, and even ash left after burning straw was a useful resource. Ash is an important source of potassium in fertilizer, and so there were ash buyers who collected ash in cities in the Edo Period. Though many cultures throughout the world are said to use ash, Japan is the only country where ash was sold to specialized merchants, as far as my own research shows. Ash was a marketable biomass product.

The remaining 20 percent was used for producing daily commodities. Philip Franz von Siebold, a German physician and botanist, wrote in his diary: "During my travels in Japan, I saw heaps of sandals made from straw everywhere. Tourists change their old sandals for new ones at fixed sites. Local farmers gather the old ones and recycle them into fertilizer." Straw sandals were much less durable than modern shoes. However, end-of-life sandals were easily recycled; they became fuel with ash being so valuable that ash buyers purchased it.

Both rice and rice straw were totally recycled back into the earth within a year. Solar energy alone supported this recycling system. In the Edo Period, more than 99 percent of kinetic power came from human labor, and humans were fed by grain mainly harvested in the previous year. The grain harvest was also the product of human labor and solar energy during the previous year. Therefore, when we consider human resource use, at present we depend on fossil fuel, but our ancestors depended on biomass.

I have often said that "Japan was a 'plant-based country' in the Edo Period." In the sense that Japanese people grew the plants on which their daily lives depended, I think the expression "plant-based country" is appropriate. We can also say "biomass-based country" to express the same thing in a trendier way. For some reason I prefer the latter so, I plan to say "Japan was a 'biomass-based country' in the Edo Period" from now on.

Biomass was also used as an energy source for light and heat. In the Edo Period, most people in cities used lanterns as lighting equipment.

Lanterns were very dim - only about one-hundredth to one-fiftieth of the brightness of a 60-Watt bulb. Lanterns also produced black soot, blackening the walls and ceiling of the house. That's why a thorough house cleaning used to be called "susuhaki," which means sweeping the soot out of the house. Thus, as lighting equipment, lanterns had some down sides.

However, the oil used for lighting was mainly from rapeseed and cotton seed sources. Thus, lighting oil was also a product ultimately extracted from the solar energy of the previous year. When oil was burned, it was converted to carbon dioxide and water, which were absorbed by plants in the following year, with oil being produced again from the harvested plants. That is, when burning oil in lanterns, people also promoted circulation in the recycling system. People took good care of plants and led their lives in a society based on biomass.

If you ask whether people led comfortable lives in this kind of biomass society, I would say that life in our current society is much easier. Especially, for people in my generation who spent their childhood during World War II, the biomass-based life of former days seemed frighteningly hard.

But, I don't really think that is true. From the era of our prehistoric ancestors down to the present, the human genome or DNA (deoxyribonucleic acid) sequence has basically not changed much. Therefore, I'm sure that our bodies are designed to be adaptable to difficult circumstances, such as food shortages and cold weather.

Meanwhile, our lifestyles have dramatically changed in only 50 years or so. The easy modern lifestyle does not put so much of a burden on our bodies, but in fact I think it might be forcing us to put a heavy burden on society as a whole.

Why do problems emerge in our present society one after another without surcease, in spite of our affluence? Lots of suggestions no doubt come to mind.

It is impossible for us to go back to a lifestyle that is 100 percent dependent on biomass. But, we might be more comfortable in a real sense, if we could return to a biomass-based life.

As a researcher working on Edo energy issues, I would like to give my opinion on how we can develop our ideas about biomass use.

I don't think we should force ourselves to increase the amount of biomass use. In our present Japanese society, it will be difficult to replace even 10% of fossil fuels with biomass.

I'm not saying that every effort is useless. We just need to do whatever we can do, however small. I think the important thing is that we try many different approaches and gain as much experience as possible.

I believe this because it is doubtful that we can continue to consume as much fossil fuel as we desire. One reason for this uncertainty is that we do not know whether Japan will continue to be an economically powerful nation. Another reason is that we might be entering an era in which we hesitate to use fossil fuels due to environmental deterioration.

One good approach that can lessen our fear of failure is to try using biomass as widely as possible. This works even better if you enjoy doing it.

As one example, Japan's food self-sufficiency is rated at 40% based on calories. At the same time, 40% of kitchen garbage collected in the city of Kyoto is comprised of leftovers, according to one researcher. The percent of leftovers is the same as Japan's food self-sufficiency ratio, meaning that this city is throwing away an amount of food equivalent to its supply of home-grown agricultural products.

According to data published by the Science and Technology Agency in 1999, Japan's gross agricultural production amounted to 12.4 trillion yen (about US$101.64 billion), while the monetary equivalent of discarded leftovers amounted to 11.1 trillion yen (about US$90.98 billion) based on market prices. In monetary terms, this means that we are dumping the equivalent of 90% of domestically-produced food.

This data implies that we are actually living on 60% of the food that is already accessible. At the same time, Japanese people are increasingly suffering from weight gain because of over-supply. So if we ever become unable to import food, 40% of the 60% we are actually living on now could be replaced with home-grown products, on the condition that we don't waste food. Calculating 40% out of 60% gives us 66.666%; this would raise Japan's food self-sufficiency to nearly 70%. And if we try to eat less and import about 10% of the food we consume, it might be possible to live without relying too much on imports.

The same goes for energy. Per capita energy consumption in the Edo period was equivalent to 0 kcal in terms of present standards; however, present, daily per capita consumption of energy from fossil fuels alone is as much as 100,000 kcal. Back in 1970, this figure was only 50,000 kcal. And I, for one, still follow more or less the same kind of lifestyle I did in the 1970s.

This means that half the amount should suffice to maintain our present lifestyle. If the fossil fuel energy supply decreases, the use of biomass will automatically increase whether we like it or not.

I find it very promising that many of you here are promoting biomass energy. I think the use of biomass is already part of our lives. There are still many people adept at making charcoal, which is a good example of biomass-derived energy, as well as those who are creating new energy sources. You don't need to try too hard to increase the use of biomass because society will soon be demanding it. For the time being, we just need to patiently try every available technology.

In the Edo period, there weren't many kinds of energy sources available except biomass, most of which was derived from fast-growing plants. You may think that tree growth would have been too slow to keep up with firewood demand, resulting in insufficient firewood supply. However, Japan's population at that time was only 30 million and only 1,000 kcal of energy from firewood was required per day. This was actually considerably less than percent of tree growth at the time. It was an era when forestry was managed properly.

Life in the olden days was no doubt hard, but you are quite mistaken if you think that people in the past were inferior and we are superior. There are many things that we should learn from their ways of life.

Photo: Edo-Tokyo Open-air Architectural Museum
Image by t.ohashi Some Rights Reserved.

From the website of Kanto Regional Agricultural Administration Office