Biomass, in the energy production industry, refers to living and recently dead biological material which can be used as fuel or for industrial production. Most commonly, biomass refers to plant matter grown for use as biofuel, but it also includes plant or animal matter used for production of fibres, chemicals or heat. Biomass may also include biodegradable wastes that can be burnt as fuel. It excludes organic material which has been transformed by geological processes into substances such as coal or petroleum. It is usually measured by dry weight.
Biomass is grown from several plants, including miscanthus, switchgrass, hemp, corn, poplar, willow and sugarcane. The particular plant used is usually not very important to the end products, but it does affect the processing of the raw material. Production of biomass is a growing industry as interest in sustainable fuel sources is growing.
The least costly, most common, and simplest method is direct combustion or burning of the biomass which produces energy for activities such as heating or cooking. Currently, numerous technologies exist that convert organic material to commercial energy.
Biomass is part of the carbon cycle. Carbon from the atmosphere is converted into biological matter by photosynthesis. On decay or combustion the carbon goes back into the atmosphere or soil. This happens over a relatively short timescale and plant matter used as a fuel can be constantly replaced by planting for new growth. Therefore a reasonably stable level of atmospheric carbon results from its use as a fuel. It is commonly accepted that the amount of carbon stored in biomass is approximately 50% of the biomass by weight.