Organic material contains energy that can be harnessed to produce electricity and/or heat. The energy in organic material is present as chemical energy that has been captured from the sun as organic matter (such as trees and plants) have grown. To be sustainable, the rate of this energy conversion (i.e. the rate of conversion from the sun to chemical energy) needs to align with the rate of any subsequent conversion by man to electrical or heat energy. The organic resource must therefore be grown, managed and used in a sustainable way. Examples of biomass projects involve the combustion of waste wood (arising from the construction and demolition sector) or virgin timber resources (which are often offcuts or felled as part of forest management programmes) in order to produce high pressure steam which can generate electricity in a turbine.
The biomass resource can also be processed prior to its use in order to maximise the energy density of the material, storage and transportation, through making a pellet. A number of coal plants in the UK, such as Drax, have converted one or all of their boilers to run entirely or partially on biomass pellets.
