Electricity and heat cogeneration from biomass fuels: A case study in Fiji

Electricity supply to rural and remote areas in developing countries is a major problem because of the large costs, population distribution, and inaccessibility of remote communities to grid extension. In Fiji, less than 40% of the rural population has access to grid electricity, most of these in the two major islands. The potential for the generation of electricity through burning biomass fuels such as sawmill and crop wastes is substantial, particularly for areas close to sawmills and forest logging sites. After establishing the availability and costs of various biomass fuels in Fiji, a system for the utilization of such wastes is described. The 25 kW rural area power supply (RAPS) system consists of a simple, low-cost furnace/boiler to generate steam which powers a simple, reciprocating steam engine to drive an alternator to supply the load. With the existence of an adequate thermal load (such as for crop drying or for hot water), an electricity/heat cogeneration system can be installed with the engine exhaust steam supplying the heat load. The advantages of such a supply system are discussed along with problems and system economics in comparison to an existing wood-fired cogeneration system.