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Present status and future prospect of geothermal energy development in Japan
ice cad other applications of CO,, the sale of this gas would bring in a much higher return than all other applications of the hot water field. After this recital of the principal characteristics of a wet steam field and the variety of the different natural resources involved, it will be appreciated that, in suitable locations and conditions, the multipurpose development of a wet steam field may have higher economic significance and profitability than a dry steam field. It may be useful at this stage to compare within the limits of comparability dry steam fields and wet steam fields from the point of view of productivity. Such comparisons need care because one should compare equals - - in other words, a good dry steam well should only be compared with a good hot water well, an average well with an average well and a low productivity well with another low productivity well. It is also essential to compare wells with equal temperature and diameter so that the technical parameters are fairly equal. If we do this, we will reach a conclusion that a good hot water well will produce three to five times the weight of hot water at approximately the same temperature as compared to a steam well. As the heat content of a ton of steam is approximately two to three times that of a ton of hot water, it nevertheless leads to the conclusion that on a comparative basis a hot water well has a total heat output of about double or more than that of a dry steam well. As a result, even if only 20% of the hot water of a wet steam field is flashed into steam, a hot water well has approximately the same electric generating capacity as a comparable dry steam well. A hot water well, therefore, can generate the same quantity of electricity as a dry steam well, but in addition, large quantities of heat in the form of hot water. Depending on the circumstances, this hot water can represent an additional heat source of greater magnitude than the heat used for electricity generation. The utilization of hot water, given its limited transportability, is basically a local problem, but in the right region and under the right conditions the utilization of such hot water may contribute in a variety of forms to the solution of energy problems in a given area. First let us properly understand the great energy savings, cost reductions and reduction in thermal pollution we can obtain wherever we can apply hot water directly. Let us compare air conditioning. We can use geothermal steam to ~enerate electricity and then use such electricity for air conditiopin~. In this case, as the efficiency in using steam for electricity f,en. eratin~ is less than 30%. 70% of the heat is discarded. Tho electricity thus ~enerated entails further energy losses in r~roriding, air conditioning - - so that as a result perhans only 20% of the energv content of geothermal steam is utilized in air conditioning. The direct, one step use of hot geothermal w;,ter for air conditioning_, using standard eouipment, may onerate at about 80% efficiency - - thus allowing, lower cost. hi~her energy utilization and smaller heat relection. The efficlencv and cost advantages of the direct use of hot geothermal wmer anoly to a wide range of agricultural processes, includln~. refri~.eration, drying, he~tinq otc. Here in the Imperial Valley. with its need for a~zricult, r,~l nrocessing, for air eonditionirm, for refri~,eration and for desalinated water, is the re~ion for the multirmrnose develonment of hot water fields. The full develor~ment in the Imperial Vail---, could become a model for trio world for the efficient utilization of the terse heat content of hot water fields. It should be noted here that geothermal water for direct applications tin air conditioninm refrigeration, etc.) does not need the high temnerature reouired for electricitv ~eneratimz. Furthermore. a full mnhirgurpose develorment of a hot water field with its much hi~ber economic return would also Justify deeoer drilling in regions where the demand for hot water exists and o-ola,,ic and hvdro~eologie conditions apoear favnurahle All this annears to be anDlicable to the lmDerial Valley. At *he suggestion of the United Nations. the Governmerit of Nicaraqua is now considering the central air cor~ditionin~ of Manamm and the nrovision of refri~eratlnn in the ind,,atri~l part of the city - - all based on geothermal hot water. This ormortunitv and challenge of a muhipurnose develor~ment of hot water fields poses, however, serious institutional r~roblems. Pnwer comnanies in many states are not nermitted to deal with water desalination mineral e~traction and. in some cases, they are not allowed to provide hot water for Mr conditioning, heating, refrigeration, etc. On the other hand,
the sate of electricity is reserved for power companies. In this dHficuit situation wnere the power companies have a monopoly posiu~,n on tlae one hand and a very narrow area of activities - - racy arc one commodity companies - - the only way out appears to me to grant to multipurpose geothermal companies tnc r~ght to produce and market all ot their products, ~lJcluclirtg eJcc,r~c]ty, this suggestion may appear in the context o, the present institutional structure to be a novel idea - - to me, ~t is a necessary ana a traditional idea. In the history of ,~merican electricity development, shortcomings at each historic stage have led to new institutional arrangements, from rural power co-operatives to municipal power systems, to governmentowned generating and transmission systems and now, with the advent o~ geotiaermal energy, we have a new set of problems. oeothermal wmer and steam are location-bound - - unlike coal, oil and all diner tuels. A geothermal power station must be built near the geothermal field. Now, if the power company possessing the monopoly for power sales is not willing to build such a station or is unwilling to pay a fair price for steam, the owner of the geothermal field is practically helpless. Moreover, if a hot water field is involved, the power company may legally not be able to undertake a multi-purpose development which may economically and nationally be the best type of developlnent. A iree hand for geothermal developers for a broad development is clearly neecled. "Ibis might also have been in the mind of Congress when iL provided in the Geothermal Steam Act of 1970 that governmental units, including, without limitation, municipalities, may acquire geothermal leases. The freedom for geomermal developers may in some cases reintroduce an element of competition - - perhaps at the wholesale level and at the retail level - - in such a vital service industry as the supply of electricity. Such a competition at this stage of the electricity industry can have only beneficial effects, both for the development of a local energy resource and for the economy as a whole. 1 believe that the expansion of the freedom of geothermal developers may, for all concerned, be more acceptable than delays and deformation which in the end may force the government to step in as it has in the case of river basin development in order to achieve multipurpose development. Geothermal energy is too important a natural resource to be considered only a steam source. Hot water fields are bound to become the most important part of the geothermal industry in this country. If the full potential of these hot water fields is to be fully developed, all parties concerned must co-operate in a spirit of new approaches and new initiatives.
United Nations Geothermal Exploration in Kenya Exploration drilling sites were selected last December in the Olkaria prospect located south of Lake Naivasha A thirteen-kilometer long, 6-inch pipe line is now being constructed from Lake Naivasha to the first site in order to provide water for drilling. In April, the United Nations awarded the drilling contract to Foramines. The contract calls for the drilling of 4500 meters distributed among four holes. Drilling is scheduled to begin in August or September of this year. (j. r. m.)
Present Status and Future Prospect of Geothermal Energy Development in Japan A n o t e by the IAPAN NATIONAL NATURAL RESOURCES DEVELOPMENT COMMITTEE - M a y 1973 Geothermal
Energy
D e v e l o p m e n t in J a p a n Y e s t e r -
day and T o d a y History The utilization of hot spas in Japan for purposes of ceremonial ablution, therapeutical treatment for injuries and illnesses, or plain bathing, has always been a popular practice, and 77
its earliest recorded description dates from as early as 729. This tradition with more than a thousand years behind it may be regarded as an example of a popular form of geothermal energy development. It was not until quite recently that positive efforts came to be made for an organized scientific and technological development of this natural energy. In 1924, Dr. Heiji Tachikawa made the first experiment to utilize it for power generation, at Beppu, Kyushu. It was a successful experiment which yielded 1 kW of electricity. It was supplied to actual electric lamps. Three years later, in 1927, the same scientist conducted the boring of a geothermal well with a view to realizing a commercial development, at Otake, Kyushu, but the attempt proved abortive, and all further pursuit of his research was abandoned. In the 1940s, however, larger-scale experiments were conducted anew at Naruko, Miyagi Prefecture, and also at Beppu, and several other places. Power in t h e range of a little less than 10 k W to some 30 kW was obtained, with rather bright promise for a future commercial development. In the 1950s, full-scale explorations for geothermal resources were begun in the Tohoku District and Kvushu. Work was started in the 1960s on the construction of geothermal power stations for commercial operation at Matsukawa in the Tohoku District and at Otake, Kyushu. Present situation A successful commercial operation of a 20 M W geothermal power station was launched at Matsukawa in 1966, and another. with an output of 13 MW at Otake, Kyushu in 1967. Both of them are in excellent operating condition. The first, named the Matsukawa geothermal power station. furnishes power to the Tohoku Electric Power Company, and the latter, the Otake geothermal power station, to the Kyushu Electric Power Company, as commercial electric service. Both these stations boast an operation rate of approximately 90%, a rate considerably higher than in the case of steam power generation by fossil fuels. These geothermal power stations were built by, and belone to, private commercial firms (the Matsukawa station was built by lanan Metals and Chemicals Co., formerly Azuma Kako Co.; the Otake station, by Kvushu Electric Power Co.). Research on development of geothermal energy and the construction of power stations utilizing this energy are in !~art aided by government subsidies. Currently. construction work is in l~ro~ress on geothermal power plants in three places, and at a fourth site exploration is being conducted. One of them is a r~roiect of Mitsubishi Metal Mining Co. The power-generating unit is already comoleted at Hachimantai-Onuma, with an outnut of 10 MW. The eauipment is under installation now. and the whole works will be in operation by the end of this year. The r)ower ~enerated at this station will be transmitted to Mitsubishi's Akita factories for their private consumption. Another r~lant under construction is at Onikobe, also in the Tohoku District, a project of Dengen Kaihatsu (, Electric Power Develooment Co. ~). Already some ten production wells have been drilled, and the actual plant construction work was begun at the beginning of this year. It is scheduled to be completed and start operating in 1975. In this particular area, the geological characteristics are such that shallow wells, not more than 300 deep, yield slightly overheated steam only. Facilities with a 25-MW capacity will first be installed. The eventual expansion of the works to follow the first phase is being studied at present. The third, a oroject of Kyushu Electric Power Co., is situated at Hatchobaru, Kvushu, not far from the site of the afore-mentioned Otake geothermal power station. Already some seven production wells have been drilled, about 1000 m deeD. each of which emits steam accompanied by heated water. It is estimated that, from one or two production wells, steam in the order of approximately 100 t/t each will be obtained. This area has great oromise for the future as a source of ~eothermal energy. The works should be completed by 1975, with a scheduled outl~ut capacity of 50 MW. The ext~loration from the research conducted in this area show that it is not impossible to foresee the operation of plants yielding an output ranging from 150 to 200 MW. Kyushu
78
Electric Power Co.'s plan for the post-phase-one period calls for further expansion of the operation. Fourthly, there is the project of developing the Katsukonda area that lies between the above-mentioned Onikobe and Matsukawa, in the Tohoku District. The Katsukonda area had for some time been closely examined as a promising site, and fullscale exploration has been in progress since last summer. Already a n u m b e r of experimental wells have been bored; at the same time, exploration by several methods are being conducted. The first phase of the work here aims at obtaining 50 MW of electricity. With further phases of the development in order. it is expected that 150 to 200 MW will be secured in this area. In the development of this area, lapan Metals and Chemicals Co. (which operates the Matsukawa Geothermal Power Station) will develop the securing of steam, while, utilizing this steam, Tohoku Electric Power C o will be in charge of the construction and operation of the completed station, a cooperative relationship similar to that between Union Oil and Pacific Gas and Electric Co. at The Geysers in America. Given the exnertise of both these enterprises in the field of development of steam and construction of thermal power plants, there is great expectation that their plans will successfully materialize in due course of time. Side by side with these four projects in progress, there exists a strong interest shown by mining companies in the development of geothermal energy. Indeed, one could say that the la,aanese archipelago sits on a network of belts blessed with a b u n d a n t geothermal energy, and in many eases in the past, mining enterprises were at a loss as to how to cope with the geothermal energy belts that would block their galleries. Abreast with the recent extensive research into the possibilities of developing geothermal energy conducted on a worldwide basis, these mining companies have begun to turn their attention to positively utilizing this energy which heretofore has been a troublesome problem for them. Such companies are scattered all over the country, from Hokkaido in the north. through the Tohoku and Chubu districts, down to Kyushu. Though none of them has vet come out of their blue-print stage, there is every reason to believe that they will he launching their preliminary explorings in the not too distant future.
Need for d e v e l o p m e n t of g e o t h e r m a l resources In answer to the energy crisis
Iapan faces a serious energy crisis. Statistical data for 1971 show that lapan's yearly demand for energy accounts roughly for what corresponds to 300 million kiloliters in terms of oil. Of this, a mea~er 15% is domestically supplied, the rest, 85%, denending on importation. This heavy dependence on imported oil is showing a steadily rising tendency year after year, and the fear is even voiced among the circles concerned that by 1975 the percentage of imported energy resources will have soared to something like 87.4. On the other hand, the deposit of geothermal energy available in lapan may be said to be inexhaustible. Although the technology available now still reauires the use of water as medium, scientists and experts believe that it is possible to develop electric energy in the order of 30 to 50, or even 60 million kW. Some scientists claim that, when the distribution of the geothermal deposit has been sounded out and relevant technological know-how is comt~leted, a potential ~eneration of nower in the order of some 140 million k W will he no unrealistic estimation. A non-pollutant source o/ energy One great social oroblem today is environmental "oollutionl In particular, the problem of polluted air is a very difficult one to solve. With very scarse natural resources of energy, tapan is comnelled to import huge quantities of oil and coal, But these are indeed the major environmental pollutants. The steam produced by geothermal energy and utilizable for power generation has been verified as not containing elements that would pollute the air. Thus, it may be said that geothermal energy is a non-pollutant type of energy. Economical In terms of production cost, the utilization of geothermal energy in all probability will prove to be more economical than any other electrlcity-generating formula.
In Japan, the construction of geothermal power plants, as things stand at present, costs more than steam power plants of fossil fuels, and more or less as much as hydro power plants. It will become necessary to look into the whys and wherefores of this fact, as in certain other countries there seems to be a more economical way to approach the matter. If, furthermore, we consider the problem from the standpoint of output, the cost for operating a small-scale geothermal plant of 10 to 20 MW roughly corresponds to that for operating a 600 MW, heavy-oil-type generator, the largest of the kind used in lapan. This is considerably costlier than in the case of The Geysers (USA), Larderello (Italy), or Wairakei (New Zealand). It is possible to reasonably forecast that the cost for the construction of geothermal plants and, therefore, the cost of power itself, will eventually be considerably lowered. On the other hand, it is predicted that the prices of oil, coal, uranium and other energy sources for which Japan depends on importation will be rising in response to the growing demand for them throughout the world. Under the circumstances, it goes without saying that Japan will have to turn to more economical energy resources available at home. This, however, is most probably not a case peculiar to lapan only. Sooner or later, it will be the same story throughout the world.
build a large number of small plants on condition that production cost can somehow be curtailed. Thirdly, japan does not yet possess sufficiently advanced techniques for exploring work. It will be necessary to develop new techniques and apparatus that would facilitate precise exploration work. Fourthly, little research has been made into the possibilities of the afore-mentioned multi-purpose utilization of geothermal energy. There is ample room for active research in this field too. What
is happening
In certain cases, steam extracted from geothermal resources is accompanied by large quantities of heated water. Such has been the case, in Japan, at Otake and Hachimantai. By putting this heated water to some other uses, the value of geothermal energy could be further elevated. One could immediately think of such possibilities as utilizing it for heating, domestic green-houses on farms, drying and other purposes on dairy farms, and so on.
Lately Japan has also seen rather conspicuous moves on the part of parties concerned with such problems as energy crisis, environmental pollution, regional development, etc., towards a concerted effort to see the development of geothermal energy realized, presumably spurred on by the many advantages that this natural energy oilers, overshadowing certain of its demerits. The Japan Geothermal Energy Association ( I . G . E . A . ) (founded in 1960) is encouraging investigation and studies of geothermal energy. Through such activities as lectures, inspection tours and seminars, the ]. G. E. A. arouses public interest. A Geothermal Resources Development Conference composed of Diet members who are interested in geothermal energy is taking the initiative in having it incorporated in the government's policy and has recently succeeded in securing the government's active cooperation in policy making, and a budget for basic investigation of geothermal energy. In accordance with the spirit with which the above-mentioned conference was organized by members of the Diet, mining companies also interested in this matter organized their own conference, where they could study the problem together, cooperate with one another and exchange information.
Problems awaiting solution
Technical cooperation w i t h o t h e r countries
There are clearly definable reasons for the slow progress being made in lapan on the further pursuit of the development of geothermal energy, despite the many advantages that it offers. For one thing, the lack of basic data on geothermal resources keeps the enterprises sceptical and uncertain of the economic merits of investment in its development. With this red signal before them, they prefer to stay safe; and, even if it is known that Japan abounds in rich geothermal resources, there is no assurance that one can find them anywhere. It is thus necessary to compile a , geothermal resources distribution map >, based on the findings of large-scale exploring expeditions across the country. Such a map with basic data would be of use in selecting a development site. Up till now. it was always the developing enterprises themselves that conducted the preliminary study and explorings in and around the area they had selected. This explains why geothermal resources development in Japan has come to be rather costly. Secondly, we cannot overlook the rather modest size of the geothermal plants that have been pioneered in Japan. True, in certain cases, this fact may prove advantageous in developing countries, but in the situation prevailing in Japan in which annually we have to keep adding plants capable of yielding some 8000 MW of power to satisfy the explosively growing demand, it is not a correct solution to have plants equipped with a small number of generators of the conventional type, each with a maximum output of some 50 MW, On the other hand, however, we can also say that, while it will undoubtedly become necessary to build larger generators and larger scale power plants, one valid solution may be to
Although Japan does not have a long experience in the field of geothermal energy development, she is equipped with a considerable number of scientists and specialists who have been studying this problem. They have lent valuable assistance not only to lapanese enterprises, but also to overseas parties interested in promoting geothermal energy development. The International Group Training Course in Geothermal Energy organizes every year a 9-week seminar to contribute to the training of attendants from developing countries in geothermal energy development. This seminar is jointly sponsored by the UNESCO National Committee, the Overseas Technical Cooperation Agency and Kryshu University, with the cooperation of the lapan Geothermal Energy Association. All expenses of the attendants, including travel, living expenses, etc., are covered by the [apanese Government and UNESCO. Three seminars have been held so far. A fourth session is forthcoming this year (1973). The countries represented at the seminars in the past three years were: Bolivia, Burma, Chile, Egypt, El Salvador, Ethiopia, Guatemala, India, Indonesia, Iran, Korea, Mexico, Nicaragua, The Philippines, Taiwan, Thailand, Turkey.
Multi-purpose development and regional development
Dispatch o/ technicians Japanese technicians were dispatched abroad, at the request of either the United Nations or specific countries, to conduct research on prospective sites for geothermal energy development. Some of them stayed for one full year, others for several months, or several weeks. They have covered the following countries: Ethiopia. Guatemala, Taiwan, etc.
ERRATUM In the p a p e r Thermal Problems in the Siting of Reinjection Wells by G. BODVARSSON, Geothermics, l u n e 1972, Vol. 1, No. 2, p a g e 64, e q u a t i o n (1) due to t y p o g r a p h i c a l e r r o r one t e r m is missing. Thus
h
=--k
V T+sT
(1)
V T + sTq
(1)
should read
h
= --k
79
the sate of electricity is reserved for power companies. In this dHficuit situation wnere the power companies have a monopoly posiu~,n on tlae one hand and a very narrow area of activities - - racy arc one commodity companies - - the only way out appears to me to grant to multipurpose geothermal companies tnc r~ght to produce and market all ot their products, ~lJcluclirtg eJcc,r~c]ty, this suggestion may appear in the context o, the present institutional structure to be a novel idea - - to me, ~t is a necessary ana a traditional idea. In the history of ,~merican electricity development, shortcomings at each historic stage have led to new institutional arrangements, from rural power co-operatives to municipal power systems, to governmentowned generating and transmission systems and now, with the advent o~ geotiaermal energy, we have a new set of problems. oeothermal wmer and steam are location-bound - - unlike coal, oil and all diner tuels. A geothermal power station must be built near the geothermal field. Now, if the power company possessing the monopoly for power sales is not willing to build such a station or is unwilling to pay a fair price for steam, the owner of the geothermal field is practically helpless. Moreover, if a hot water field is involved, the power company may legally not be able to undertake a multi-purpose development which may economically and nationally be the best type of developlnent. A iree hand for geothermal developers for a broad development is clearly neecled. "Ibis might also have been in the mind of Congress when iL provided in the Geothermal Steam Act of 1970 that governmental units, including, without limitation, municipalities, may acquire geothermal leases. The freedom for geomermal developers may in some cases reintroduce an element of competition - - perhaps at the wholesale level and at the retail level - - in such a vital service industry as the supply of electricity. Such a competition at this stage of the electricity industry can have only beneficial effects, both for the development of a local energy resource and for the economy as a whole. 1 believe that the expansion of the freedom of geothermal developers may, for all concerned, be more acceptable than delays and deformation which in the end may force the government to step in as it has in the case of river basin development in order to achieve multipurpose development. Geothermal energy is too important a natural resource to be considered only a steam source. Hot water fields are bound to become the most important part of the geothermal industry in this country. If the full potential of these hot water fields is to be fully developed, all parties concerned must co-operate in a spirit of new approaches and new initiatives.
United Nations Geothermal Exploration in Kenya Exploration drilling sites were selected last December in the Olkaria prospect located south of Lake Naivasha A thirteen-kilometer long, 6-inch pipe line is now being constructed from Lake Naivasha to the first site in order to provide water for drilling. In April, the United Nations awarded the drilling contract to Foramines. The contract calls for the drilling of 4500 meters distributed among four holes. Drilling is scheduled to begin in August or September of this year. (j. r. m.)
Present Status and Future Prospect of Geothermal Energy Development in Japan A n o t e by the IAPAN NATIONAL NATURAL RESOURCES DEVELOPMENT COMMITTEE - M a y 1973 Geothermal
Energy
D e v e l o p m e n t in J a p a n Y e s t e r -
day and T o d a y History The utilization of hot spas in Japan for purposes of ceremonial ablution, therapeutical treatment for injuries and illnesses, or plain bathing, has always been a popular practice, and 77
its earliest recorded description dates from as early as 729. This tradition with more than a thousand years behind it may be regarded as an example of a popular form of geothermal energy development. It was not until quite recently that positive efforts came to be made for an organized scientific and technological development of this natural energy. In 1924, Dr. Heiji Tachikawa made the first experiment to utilize it for power generation, at Beppu, Kyushu. It was a successful experiment which yielded 1 kW of electricity. It was supplied to actual electric lamps. Three years later, in 1927, the same scientist conducted the boring of a geothermal well with a view to realizing a commercial development, at Otake, Kyushu, but the attempt proved abortive, and all further pursuit of his research was abandoned. In the 1940s, however, larger-scale experiments were conducted anew at Naruko, Miyagi Prefecture, and also at Beppu, and several other places. Power in t h e range of a little less than 10 k W to some 30 kW was obtained, with rather bright promise for a future commercial development. In the 1950s, full-scale explorations for geothermal resources were begun in the Tohoku District and Kvushu. Work was started in the 1960s on the construction of geothermal power stations for commercial operation at Matsukawa in the Tohoku District and at Otake, Kyushu. Present situation A successful commercial operation of a 20 M W geothermal power station was launched at Matsukawa in 1966, and another. with an output of 13 MW at Otake, Kyushu in 1967. Both of them are in excellent operating condition. The first, named the Matsukawa geothermal power station. furnishes power to the Tohoku Electric Power Company, and the latter, the Otake geothermal power station, to the Kyushu Electric Power Company, as commercial electric service. Both these stations boast an operation rate of approximately 90%, a rate considerably higher than in the case of steam power generation by fossil fuels. These geothermal power stations were built by, and belone to, private commercial firms (the Matsukawa station was built by lanan Metals and Chemicals Co., formerly Azuma Kako Co.; the Otake station, by Kvushu Electric Power Co.). Research on development of geothermal energy and the construction of power stations utilizing this energy are in !~art aided by government subsidies. Currently. construction work is in l~ro~ress on geothermal power plants in three places, and at a fourth site exploration is being conducted. One of them is a r~roiect of Mitsubishi Metal Mining Co. The power-generating unit is already comoleted at Hachimantai-Onuma, with an outnut of 10 MW. The eauipment is under installation now. and the whole works will be in operation by the end of this year. The r)ower ~enerated at this station will be transmitted to Mitsubishi's Akita factories for their private consumption. Another r~lant under construction is at Onikobe, also in the Tohoku District, a project of Dengen Kaihatsu (, Electric Power Develooment Co. ~). Already some ten production wells have been drilled, and the actual plant construction work was begun at the beginning of this year. It is scheduled to be completed and start operating in 1975. In this particular area, the geological characteristics are such that shallow wells, not more than 300 deep, yield slightly overheated steam only. Facilities with a 25-MW capacity will first be installed. The eventual expansion of the works to follow the first phase is being studied at present. The third, a oroject of Kyushu Electric Power Co., is situated at Hatchobaru, Kvushu, not far from the site of the afore-mentioned Otake geothermal power station. Already some seven production wells have been drilled, about 1000 m deeD. each of which emits steam accompanied by heated water. It is estimated that, from one or two production wells, steam in the order of approximately 100 t/t each will be obtained. This area has great oromise for the future as a source of ~eothermal energy. The works should be completed by 1975, with a scheduled outl~ut capacity of 50 MW. The ext~loration from the research conducted in this area show that it is not impossible to foresee the operation of plants yielding an output ranging from 150 to 200 MW. Kyushu
78
Electric Power Co.'s plan for the post-phase-one period calls for further expansion of the operation. Fourthly, there is the project of developing the Katsukonda area that lies between the above-mentioned Onikobe and Matsukawa, in the Tohoku District. The Katsukonda area had for some time been closely examined as a promising site, and fullscale exploration has been in progress since last summer. Already a n u m b e r of experimental wells have been bored; at the same time, exploration by several methods are being conducted. The first phase of the work here aims at obtaining 50 MW of electricity. With further phases of the development in order. it is expected that 150 to 200 MW will be secured in this area. In the development of this area, lapan Metals and Chemicals Co. (which operates the Matsukawa Geothermal Power Station) will develop the securing of steam, while, utilizing this steam, Tohoku Electric Power C o will be in charge of the construction and operation of the completed station, a cooperative relationship similar to that between Union Oil and Pacific Gas and Electric Co. at The Geysers in America. Given the exnertise of both these enterprises in the field of development of steam and construction of thermal power plants, there is great expectation that their plans will successfully materialize in due course of time. Side by side with these four projects in progress, there exists a strong interest shown by mining companies in the development of geothermal energy. Indeed, one could say that the la,aanese archipelago sits on a network of belts blessed with a b u n d a n t geothermal energy, and in many eases in the past, mining enterprises were at a loss as to how to cope with the geothermal energy belts that would block their galleries. Abreast with the recent extensive research into the possibilities of developing geothermal energy conducted on a worldwide basis, these mining companies have begun to turn their attention to positively utilizing this energy which heretofore has been a troublesome problem for them. Such companies are scattered all over the country, from Hokkaido in the north. through the Tohoku and Chubu districts, down to Kyushu. Though none of them has vet come out of their blue-print stage, there is every reason to believe that they will he launching their preliminary explorings in the not too distant future.
Need for d e v e l o p m e n t of g e o t h e r m a l resources In answer to the energy crisis
Iapan faces a serious energy crisis. Statistical data for 1971 show that lapan's yearly demand for energy accounts roughly for what corresponds to 300 million kiloliters in terms of oil. Of this, a mea~er 15% is domestically supplied, the rest, 85%, denending on importation. This heavy dependence on imported oil is showing a steadily rising tendency year after year, and the fear is even voiced among the circles concerned that by 1975 the percentage of imported energy resources will have soared to something like 87.4. On the other hand, the deposit of geothermal energy available in lapan may be said to be inexhaustible. Although the technology available now still reauires the use of water as medium, scientists and experts believe that it is possible to develop electric energy in the order of 30 to 50, or even 60 million kW. Some scientists claim that, when the distribution of the geothermal deposit has been sounded out and relevant technological know-how is comt~leted, a potential ~eneration of nower in the order of some 140 million k W will he no unrealistic estimation. A non-pollutant source o/ energy One great social oroblem today is environmental "oollutionl In particular, the problem of polluted air is a very difficult one to solve. With very scarse natural resources of energy, tapan is comnelled to import huge quantities of oil and coal, But these are indeed the major environmental pollutants. The steam produced by geothermal energy and utilizable for power generation has been verified as not containing elements that would pollute the air. Thus, it may be said that geothermal energy is a non-pollutant type of energy. Economical In terms of production cost, the utilization of geothermal energy in all probability will prove to be more economical than any other electrlcity-generating formula.
In Japan, the construction of geothermal power plants, as things stand at present, costs more than steam power plants of fossil fuels, and more or less as much as hydro power plants. It will become necessary to look into the whys and wherefores of this fact, as in certain other countries there seems to be a more economical way to approach the matter. If, furthermore, we consider the problem from the standpoint of output, the cost for operating a small-scale geothermal plant of 10 to 20 MW roughly corresponds to that for operating a 600 MW, heavy-oil-type generator, the largest of the kind used in lapan. This is considerably costlier than in the case of The Geysers (USA), Larderello (Italy), or Wairakei (New Zealand). It is possible to reasonably forecast that the cost for the construction of geothermal plants and, therefore, the cost of power itself, will eventually be considerably lowered. On the other hand, it is predicted that the prices of oil, coal, uranium and other energy sources for which Japan depends on importation will be rising in response to the growing demand for them throughout the world. Under the circumstances, it goes without saying that Japan will have to turn to more economical energy resources available at home. This, however, is most probably not a case peculiar to lapan only. Sooner or later, it will be the same story throughout the world.
build a large number of small plants on condition that production cost can somehow be curtailed. Thirdly, japan does not yet possess sufficiently advanced techniques for exploring work. It will be necessary to develop new techniques and apparatus that would facilitate precise exploration work. Fourthly, little research has been made into the possibilities of the afore-mentioned multi-purpose utilization of geothermal energy. There is ample room for active research in this field too. What
is happening
In certain cases, steam extracted from geothermal resources is accompanied by large quantities of heated water. Such has been the case, in Japan, at Otake and Hachimantai. By putting this heated water to some other uses, the value of geothermal energy could be further elevated. One could immediately think of such possibilities as utilizing it for heating, domestic green-houses on farms, drying and other purposes on dairy farms, and so on.
Lately Japan has also seen rather conspicuous moves on the part of parties concerned with such problems as energy crisis, environmental pollution, regional development, etc., towards a concerted effort to see the development of geothermal energy realized, presumably spurred on by the many advantages that this natural energy oilers, overshadowing certain of its demerits. The Japan Geothermal Energy Association ( I . G . E . A . ) (founded in 1960) is encouraging investigation and studies of geothermal energy. Through such activities as lectures, inspection tours and seminars, the ]. G. E. A. arouses public interest. A Geothermal Resources Development Conference composed of Diet members who are interested in geothermal energy is taking the initiative in having it incorporated in the government's policy and has recently succeeded in securing the government's active cooperation in policy making, and a budget for basic investigation of geothermal energy. In accordance with the spirit with which the above-mentioned conference was organized by members of the Diet, mining companies also interested in this matter organized their own conference, where they could study the problem together, cooperate with one another and exchange information.
Problems awaiting solution
Technical cooperation w i t h o t h e r countries
There are clearly definable reasons for the slow progress being made in lapan on the further pursuit of the development of geothermal energy, despite the many advantages that it offers. For one thing, the lack of basic data on geothermal resources keeps the enterprises sceptical and uncertain of the economic merits of investment in its development. With this red signal before them, they prefer to stay safe; and, even if it is known that Japan abounds in rich geothermal resources, there is no assurance that one can find them anywhere. It is thus necessary to compile a , geothermal resources distribution map >, based on the findings of large-scale exploring expeditions across the country. Such a map with basic data would be of use in selecting a development site. Up till now. it was always the developing enterprises themselves that conducted the preliminary study and explorings in and around the area they had selected. This explains why geothermal resources development in Japan has come to be rather costly. Secondly, we cannot overlook the rather modest size of the geothermal plants that have been pioneered in Japan. True, in certain cases, this fact may prove advantageous in developing countries, but in the situation prevailing in Japan in which annually we have to keep adding plants capable of yielding some 8000 MW of power to satisfy the explosively growing demand, it is not a correct solution to have plants equipped with a small number of generators of the conventional type, each with a maximum output of some 50 MW, On the other hand, however, we can also say that, while it will undoubtedly become necessary to build larger generators and larger scale power plants, one valid solution may be to
Although Japan does not have a long experience in the field of geothermal energy development, she is equipped with a considerable number of scientists and specialists who have been studying this problem. They have lent valuable assistance not only to lapanese enterprises, but also to overseas parties interested in promoting geothermal energy development. The International Group Training Course in Geothermal Energy organizes every year a 9-week seminar to contribute to the training of attendants from developing countries in geothermal energy development. This seminar is jointly sponsored by the UNESCO National Committee, the Overseas Technical Cooperation Agency and Kryshu University, with the cooperation of the lapan Geothermal Energy Association. All expenses of the attendants, including travel, living expenses, etc., are covered by the [apanese Government and UNESCO. Three seminars have been held so far. A fourth session is forthcoming this year (1973). The countries represented at the seminars in the past three years were: Bolivia, Burma, Chile, Egypt, El Salvador, Ethiopia, Guatemala, India, Indonesia, Iran, Korea, Mexico, Nicaragua, The Philippines, Taiwan, Thailand, Turkey.
Multi-purpose development and regional development
Dispatch o/ technicians Japanese technicians were dispatched abroad, at the request of either the United Nations or specific countries, to conduct research on prospective sites for geothermal energy development. Some of them stayed for one full year, others for several months, or several weeks. They have covered the following countries: Ethiopia. Guatemala, Taiwan, etc.
ERRATUM In the p a p e r Thermal Problems in the Siting of Reinjection Wells by G. BODVARSSON, Geothermics, l u n e 1972, Vol. 1, No. 2, p a g e 64, e q u a t i o n (1) due to t y p o g r a p h i c a l e r r o r one t e r m is missing. Thus
h
=--k
V T+sT
(1)
V T + sTq
(1)
should read
h
= --k
79