The steam first powers an electric generator and subsequently is used for heating, refrigeration or manufacturing processes. Biomass energy is energy produced from organic materials. These materials include wood, bagasse, crop residues, solid waste, animal wastes, sewage, and waste from food processing. Energy derived from biomass includes gas, electricity, liquid fuels, dry heat, and steam. Wood fuel, energy from waste, and alcohol fuels are the three main forms of bioenergy.
Alcohol fuels are a means of harnessing bioenergy.
It is produced from a variety of sugar and grain crops via the processes of fermentation. Another alcohol, methanol, can be produced from wood and agricultural wastes, natural gas and coal. It is a potential replacement motor fuel, although its main use today is as an industrial chemical. Active solar heating of space and water is accomplished by collecting sunlight through solar collectors, using pumps or fans, to heat liquid or air. Active solar cooling technologies include refrigerant-based systems which use a heat pump to produce a cool flow of air.