Biomass resources already represent just under 85% of UK renewable energy supply.* This is equivalent to approximately 1.4% of total UK primary energy use and there is scope for considerable further development.

 

Biomass is a low carbon fuel source because the carbon dioxide released when biomass is converted for energy purposes is largely offset by that absorbed by the organic material during its growth. With the appropriate management this can be recaptured with new growth.

 

However, other energy inputs may affect this carbon balance, for example via the energy used by vehicles harvesting or transporting the biomass to its point of use. Combusting biomass fuels such as wood, straw or energy crops (for example, willow coppice or specific types of grasses) to raise heat or steam for space or process heating is one of the most cost-effective applications for biomass from a cost-of-carbon point of view at the present time.

 

Biomass heating plant can come in a wide range of sizes from a few KW's to many MW of heat. For biomass CHP (combined heat and power), sizes tend to range from around 1MW to many MW of electrical generation capacity. At the smaller sizes, fuel is usually supplied as wood pellets or wood chips. Hand-fed, log-based systems are rare outside the domestic sector. At the larger scale, wood chip is one of the most common fuels at present.

 

To install a biomass boiler or CHP plant, a reliable and accessible source of fuel must be located, as well as a suitable supplier. Biomass is a particularly attractive generation option for businesses that produce a by-product that can be used as a fuel, either alone or in combination with bought-in biomass fuels.

 

Adequate space is also necessary to accommodate fuel storage and delivery. For example, a 20kW thermal boiler typically consumes 0.6m3 of wood chip daily in winter, and the volume of one tonne of dried wood is about 6m3. If possible, the fuel-transfer distance should be minimized.