28 



systems so that the farmer or an individual in the rural communi- 

 ty could generate a good deal of their own gas needs. 



Mr. AuCoiN. Would it be a good idea to expand that research, 

 and see if you could have nonrural application, nonfarm applica- 

 tions? 



Mr. Adams. I think that we will be able to have — I do not have 

 the answer to that right now, but I think that 



[The following was received for the record:] 



Question. How practical are small waste digesters for urban dwellers? 



Answer. Single, urban families do not generate sufficient waste to make small 

 digesters practical. Furthermore, small urban digestors are not practical for most 

 areas in the United States because they require heating to 95° F. This heating 

 capacity is provided by the mild climate in many of the so called Developing 

 Countries where small digestors are used, for example, India, Southern China, 

 Taiwan, and the Philippines. 



Question. Would it be a good idea to expand research on small scale digestors for 

 non-rural, non-farm applications? 



Answer. The DOE has an extensive program in anaerobic digestion of animal and 

 agricultural wastes. Both large scale and small scale digestors for farm application 

 are being developed to advance the technology. Work is going on at Cornell Univer- 

 sity and other universities and agricultural stations. This work is in collaboration 

 with the U.S. Department of Agriculture. In fiscal year 1980 intensified efforts are 

 being directed to improve the designs for small scale use, in order to provide off the 

 shelf equipment and simplified technology. 



DOE efforts are also being expended on the potential of using agricultural wastes, 

 for example straw, as gas producing commodities. While technical improvements 

 have been made, costs will remain high for the value of gas produced. 



Further work has been proposed by Cornell University on an innovative anaero- 

 bic digestion system developed by the Chinese. The Chinese effort is a national one, 

 using ponds constructed in communes. It works and is effective in the Chinese 

 culture, but is directed more toward pollution control of villages and communes. 

 The program is to direct more efforts to producing systems that can be applied to 

 smaller communities, up to ten thousand population for the purposes of both pollu- 

 tion control and for production of gas that can be used to substitute for fossil fuel. 



Mr. AuCoiN. You do not know if that would be a good idea? 



Mr. Adams. I think that I would like to get back to an answer to 

 you, after the public meetings, that we are having on October 28 

 and 29, looking specifically to answers about solar energy applica- 

 tions in the cities. That is specifically the focus of DOE public 

 forum which we are having, and that is one of the panels that will 

 be held, and I am extremely interested in the results of that panel 

 work, because so many of the renewable technologies seem to work 

 extremely well in the countryside, but we also have to do some- 

 thing about problems in the cities, where people live. 



Mr. AuCoiN. But you are unable to tell me whether it might be a 

 good idea, until that meeting is held? 



Mr. Adams. I would like to have the input from that 



Mr. AuCoiN. You mentioned in your statement that the bacterial 

 digestion process produces both methane and carbon dioxide. 



Has the Department determined how much impact this would 

 have on carbon dioxide problems in the atmosphere, and does the 

 amount of carbon dioxide released in the manufacturing and use of 

 biomass methane compare with the amount of carbon dioxide re- 

 leased in the comparable amounts of coal? Have you made any 

 comparable comparisons on that question? 



Dr. San Martin. On the specific level that you are asking, I am 

 not aware of any definitive studies that have been undertaken. 



If I could have the liberty to answer a more general type of 

 question. 



