Biomass availability, energy consumption and biochar production in rural households of Western Kenya.

Pyrolytic cook stoves in smallholder farms may require different biomass supply than traditional bioenergy approaches. Therefore, we carried out an on-farm assessment of the energy consumption for food preparation, the biomass availability relevant to conventional and pyrolytic cook stoves, and the potential biochar generation in rural households of western Kenya. Biomass availability for pyrolysis varied widely from 0.7 to 12.4 Mg ha � 1 y � 1 with an average of 4.3 Mg ha � 1 y � 1 , across all 50 studied farms. Farms with high soil fertility that were recently converted to agriculture from forest had the highest variability (CV ¼ 83%), which was a result of the wide range of farm sizes and feedstock types in the farms. Biomass variability was two times lower for farms with low than high soil fertility (CV ¼ 37%). The reduction in variability is a direct consequence of the soil quality, coupled with farm size and feedstock type. The total wood energy available in the farms (5.3 GJ capita � 1 y � 1 ) was not sufficient to meet the current cooking energy needs using conven