Himachal Pradesh is a hilly state and, due to the undulating topography and wide variation in climatic conditions, there is a restriction in propagation of all the approved biogas plants for the whole of the state. Of the approved models, fixed-dome-type biogas plants, Janta and Deenbandhu, have been propagated since 1982. In recent years, KVIC has been installing drum-type biogas plants in the lower parts of the state. About 35 647 of these biogas plants have been installed since 1982 by the Department of Agriculture, the main agency in the state. There is potential to install nearly 0.332 million family size (2 m(3)) biogas plants which could produce 0.515 million cubic metres of biogas per day with energy equivalent to about 1801.1 tonnes of fuel wood. In addition, these plants could provide nitrogen-rich manure equivalent to 133.0 tonnes of N, 91.4 tonnes of P2O5 and 66.4 tonnes of K2O daily. The functioning of plants in the state is, however low due to lack of technical know-how, improper selection, poor supervision, defective components, lack of a suitable model, non-involvement of private entrepreneur/non-government organisations, poor planning and inadequate monitoring. (C) 1997 Elsevier Science Ltd.