For a given area, these can fix more CO 2 than higher plants. The biomass that is produced can be used for energy, chemicals or food and the wastes can be converted or recycled into useful by-products. Energy and heat production from energy crops is likely to become competitive following further technical development. However, biomass may be limited by the low energy density, and associated high transport costs. Wood crops, wind and solar PV have interesting opportunities as significant suppliers of electricity in the medium and longer term.
Renewable sources can contribute energy with little or no carbon emissions.
One type of renewable fuel which has been studied by the IEA GHG Programme is biomass. Used as a fuel source, biomass has the attraction that carbon emitted on combustion has all been, previously, absorbed from the atmosphere by growing plants. Providing little other energy is used in the processing of the biomass, net emissions over the life-cycle should be small. However, with increasing scale of production, the number of biomass power plants will necessarily rise faster than would be the case for fossil fuel plant and issues such as availability of land and biomass supply may become of greater concern. The results show that biomass would be available in quantities sufficient to supply several percent of national electricity demand.