Electricity results from the movement of electrons that can be generated by moving an alternator. The driving force is generated by an internal combustion engine or a turbine driven by steam, by the combustion of bio-gas or bio-fuel. The driving force that drives the alternator can also be the wind or a stream of water.
Generating electricity with biomass?
Since electricity is derived from a motive force generated with steam or gas, biomass can be a raw material for its production. Any biomass can be used:
- Solid biomass (wood, miscanthus, straw, etc.) can be burned to create steam.
- Fermentable biomasses (agricultural residues, livestock manure) can be converted into biogas or bioethanol which will be used to power the engine or the turbine.
- Oilseed biomass (rapeseed, sunflower) can produce oil (pure vegetable oil or biodiesel) that will be used to power the engine.
Power and Performance
Turbines are used for (very) large installations with power ranging from a few megawatts to several gigawatts. They are found in coal, gas, or nuclear power plants and more recently in wood-fired power plants.
Combustion engines have a lower power ranging from a few kilowatts to 1 to 2 megawatts and require a liquid or gaseous fuel. They are used in small installations and are very suitable for the decentralised production of electricity from biomass (pure vegetable oil, biogas).
Electricity generation yields are in the order of 25-45% depending on the type of fuel, the power developed and the technology used.