The research and development programme undertaken since 1979 by the Energy Technology Support Unit (E.T.S.U.) on behalf of the Department of Energy is reviewed. It has resolved many of the original uncertainties concerning on-farm production of biogas. It has also demonstrated that in number of pilot and commercial farm-scale the digestion of animal wastes and other feedstocks from plant material is technically feasible.
However, the economic viability of a typical farm installation (based on either the traditional stirred-tank digester or more advanced designs) is likely to be poor, resulting in long or even infinite payback periods. The national benefit from agricultural anaerobic-digestion system is therefore likely to be insignificant unless credit can be given for resulting environmental improvements.
In some circumstances, an individual farmer may well be advised to invest in an anaerobic-digestion plant if he has a specific environmental problem (rather than as the major objective of producing an on-farm energy supply). However, the biogas produced could be used to offset the costs involved in controlling the problem.
Because the current British environmental regulations are unlikely to be made more stringent in the foreseeable future, there appears to be little need for further research and development into on-farm biogas. Consquently the E.T.S.U. programme has been conducted, but a watching brief will be maintained should future developments occur which might make biogas production more attractive.
Copyright © 1990 Published by Elsevier B.V.