Many agricultural and forest product residues can provide feedstock for energy conversion without increasing land requirements.
To name a few, the biomass can be any carbonaceous materials similar to the following:
- Agricultural residues: maize, rice and peanut husks or cow manure
- Forest residues: wood chips, coal, shrubs or sawdust
The quality, type and amount of raw material fed into the gasifier (feedstock) determines the amount of electricity produced. Respectively different types of gasifieres are designed for different feedstock.
Hence the appropriate feedstock has to be chosen according to:
- Availability: quantity of available biomass, sustainability of biomass supply, costs for its collection, transport, and conditioning
- Appropriate quality, moisture, composition, homogeneity purity
To give an exapmle of the, in Germany, mainly cow manure and energy crops are used as feedstock. About 2 livestock units (Großvieheinheiten (GV): 1 GV corresponds to about 1 cow or 6 rearing pigs) plus 1 ha of maize and grass yield a constant output of about 2 kW. For the South Asian context ESMAP calculates with a typical specific input-output relation of about 14 kg of fresh cattle dung (approx. produced by one cow on one day) plus 0.06 l diesel fuel to produce 1kWh electricity.