Converting biomass to electricity on a farm-sized scale using downdraft gasification and a spark-ignition engine

The search for renewable, CO2-neutral sources of electricity has prompted a surge of interest in ways of converting coppice willow and poplar into electricity. The fall in farm revenues and the rising cost of excess food production make generation of electricity from biomass on a farm-scale attractive. Work has been undertaken to demonstrate that gasification of coppice-grown comminuted wood and the subsequent conversion of the gas into electricity is feasible on a farm-sized scale. This work has been done on an experimental downdraft gasification plant and engine system capable of producing 30 kW electrical (kWe) and 60 kW of heat. The work has shown that gasification of wood-chip on this scale is possible and that it would be feasible to generate and export the electricity produced, although there are still problems to be resolved. No attempt has been made here to address the economic feasibility of the system, since the capital costs of the equipment installed are still subject to commercial confidentiality, and are artificially inflated by the costs of producing individual units. Economics will be a part of later work as firmer data are acquired.