Biomass is a form of renewal energy derived from organic sources such as plants and animal bi-products. This can include crop residues, garden waste and manure. Agricultural products grown for biomass use include corn and soybeans, wheat, rapeseed, sugar beet and sugar cane. These can be used in a system of anaerobic digestion to produce biogas. Second generation biofuels include straw, timber, manure, food husks, food waste and sewerage. Biomass fuel usage contributes to waste management as well as preventing further global warming. Landfill sites are an excellent source of biomass, producing methane gas which can be harvested and used for heating and transport fuels. Solid biofuels include timber, charcoal, sawdust, grass cuttings, domestic waste and agricultural waste. Use of biomass ensures the growth of sustainable local woodland management, and feeds into the local economy.
Biomass boilers are easy to maintain and operate. Working on wood chips and wood pellets, fuel is easy to source and can be delivered into a fuel store which automatically feeds into the boiler. A special boiler and storage space are required. Fuel storage is determined by the distance from the boiler and access to the property, and can be in the form of an underground or above ground tank. Storage space is by far the most costly part of converting to biomass. Wood combustion produces ash which can be automatically removed or removed manually. It is safe for use as a garden fertiliser. Manually operated boiler systems need to be cleaned out every 6-12 months, although there are automatic cleaning boiler systems available. As chimney flues collect deposits of tar and soot, these too require regular cleaning every one or two years. Motor and auger bearings require greasing annually.
Domestic biomass systems provide heat and water. Boilers that connect to central heating systems are usually larger than 15kw. Stand alone wood burning stoves provide heating for one room, with an output of 6-12kw, and can be connected to a back boiler for hot water provision. An appropriate chimney or flue is needed and may require planning permission. In smokeless zones, exempted systems must be used. Biomass systems are impractical for hot water production in summer as they produce unwanted heat in the house. However, they work well in combination with solar energy systems
The cost of installation varies according to requirements. A stand alone room heater costs around £3,000 to install. A boiler costs £5,000-11,000 installed, including flue and commissioning, with a manual loading boiler costing less.
A biomass powered boiler system can save a household up to £350 per year, with carbon emission savings of 6-7 tonnes per year. Grants are available, but to be eligible a certified installer and products must be used. Biomass provides savings for the household and environment and is an economical way of heating space and water.