Low Energy House - What is Biomass? - Wood Burning Stoves
Biomass is living and recently dead biological material that can be used for fuel. It consists of plant matter, animal by-products and general waste products. If biomass originates from a sustainable source then it can be considered as a renewable energy
Biomass - Fossilised Fuels
Biomass excludes any organic material which has been transformed by biological processes into fossilised fuel, such as coal and petroleum. Although fossil fuels were originally created from biomass, they are not generally considered to be biomass because they contain carbon that has been outside the carbon cycle for a considerable length of time.
Biomass - Wood Fuel for Wood Burning Stoves
Wood fuel is one of the most environmentally friendly ways of heating individual rooms or a whole house, because timber is carbon neutral fuel. Wood fuel is readily available as logs, wood chips, bark, sawdust and wood pellets. Wood can also be obtained by coppicing, whereby wood is removed in rotation from young willow and poplar trees.
Biomass - Wood Burning Stoves
Wood burning heaters are typically sealed units manufactured from either cast iron or steel. They operate at around 75 per cent efficiency whereas an open fire operates at only 15 to 20 per cent efficiency. Wood burning heaters require regular feeding with good quality, clean, dry wood.
Biomass Boilers - Domestic Heating
To provide heating and domestic hot water a log fired stove with a combined boiler is required. Wood burning stoves with back-boilers can provide most of the required domestic hot water in a house. Larger models are capable of supporting domestic central heating systems and are very cost effective. Wood burning stoves will usually have an output of 6-12 kilowatts. Wood burning stoves connected to central heating and hot water system are generally bigger, at 15 kilowatts.
Biomass - Wood Pellet Boilers
Wood pellet boilers are a recent development for wood fired pellet heating and range in output
from 15 kilowatts to over 500 kilowatts outputs. The wood pellets themselves are made from the by-products of saw mills. The domestic boiler systems are computer controlled to optimise combustion and achieve efficiency levels of around 90 per cent. To overcome the problems of wood storage and regular feeding most pellet boilers incorporate automatic pellet feed hoppers which only require re-filling every 2 to 3 days.
Biomass Burners - Smokeless Zones
Wood burning stoves can be used in areas that are not smokeless zones. In areas that are smokeless zones, wood can only be burnt on wood burning stoves that are exempted under the Clean Air Act.
Planning Permission for Biomass Burners
Planning permission may be required for a new chimney or flue. In these circumstances it is advisable to discuss the proposals with the
local planning authority before having a wood burning stove installed.
Building Regulations and Biomass Burners
Wood burning stoves, wood burning boilers, chimneys and flue installations must all comply with the Building Regulations. It may therefore be necessary to consult the Local Authority, Building Control Service.
In most circumstances, where a competent person such as a HETAS (Heating Equipment Testing and Approval Scheme) registered installer is employed to carry out
the work, it may not be necessary to involve the Building Control Service. This exemption will usually apply where the building is less than three storeys and where the solid fuel burning appliance is less than 50 kilowatts. It may also apply where heating and hot water service systems are connected to a wood burning stove.
Biomass Burners - Installation Costs
The cost of a wood burning heater generally depends on the size and type of system chosen. The installed cost of a stand alone room heater is generally between £200 and £4,000. A wood pellet boiler to serve an average sized three bedroom semi-detached house will be about 20 kilowatts and will typically cost between £5,000 and £14,000.
Biomass Burners - Running Costs
Fuel costs are largely dependant on the distance from the wood supplier. Wood is typically up to 30 per cent cheaper than oil or gas and there are considerable environmental benefits if the wood is sourced locally.
The length of the payback period will depend on the fuel being replaced and the type of wood fuel being used. Payback will be more favourable in an area that does not have a natural gas supply network
About Biomass? - Biomass Burners - Biomass Boilers