Ourpower Guides - Biomass - Details

Wood ChipBiomass is produced from organic or plant-based materials, either directly from plants or indirectly from industrial, commercial, domestic or agricultural products and by-products.

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Biomass falls into two main categories:

• Woody biomass includes forest products, untreated wood products, energy crops and short rotation coppice (SRC), which are quick-growing trees like willow.
• Non-woody biomass includes animal waste, industrial and biodegradable municipal products from food processing and energy crops. Examples are rape, sugar cane, maize.

Uses

Domestic biomass systems and those suitable for small businesses are used for:

• Producing heat to warm the room in which the appliance is sited.
• Supplying heat and hot water throughout a building.
• Biomass systems that produce electricity are currently not available at a domestic level.

How do Biomass systems work?

There are two main ways of using biomass to heat a domestic property or small business:Pellet Stove

• Stand alone stoves providing space heating for a room. Logs or wood pellets may be used as fuel but only pellets are suitable for automatic feed. Generally they are 6-12 kilowatts in output, and some models can be fitted with a back boiler to also provide water heating.
• Boilers connected to central heating and hot water systems. These are suitable for pellets, logs or chips, and are generally larger than 15 kW.

There are many domestic log, wood chip and wood pellet burning central heating boilers available. Log boilers must be loaded by hand and may be unsuitable for some situations. Automatic pellet and wood chip systems can be more expensive. Many boilers will dual fire both wood chips and pellets, although the wood chip boilers need larger hoppers to provide the same time interval between refuelling. Some systems will also burn energy crops such as wheat.
For small-scale domestic applications of biomass the fuel usually takes the form of wood pellets, wood chips or wood logs.

The benefits - why install?

• Biomass is a sustainable fuel that typically has both environmental and economic advantages.
• Unlike other renewable energy sources, biomass must be sourced and most often bought. It is most cost effective when a local fuel source is used, which results in cheaper delivery and also minimises transport miles to your home.
• Burning biomass for heat and hot water is carbon neutral since the CO2 released when burnt is equal to the CO2 absorbed during the growth of the biomass fuel.

Is it suitable for my home?

Factors that need to be considered are typically the following:

• Fuel can often be bulky - suitable space is needed for storage and for automatic loading if required.
• Local fuel supplies can be an important factor in minimising cost.
• An appropriate chimney or flue is required which may require planning permission. In smokeless zones, appropriately exempted systems must be used.
• Building regulations must be adhered to.
• Smaller systems installed within the home or office that may, with a back boiler, provide hot water and central heating are typically, may not be suitable for use all year round. In summer, too much heat would be produced in the room. External systems however remain useable all year round, although often other hot water systems - such as Solar Thermal systems - are employed in summer.

An accredited installer or supplier will help you plan the best system for your circumstances and budget.

Installation, maintenance and costs

Stand alone room heaters generally cost around £3,000 installed.
The cost for boilers varies depending on the system choice; a typical 15kW (average size required for a three-bedroom semi detached house) pellet boiler would cost around £5,000 - £11,000 installed, including the cost of the flue and commissioning. A manual log feed system of the same size would be slightly cheaper. A biomass powered boiler could save you up to £350 a year in energy bills and 6 - 7 tonnes of C02 per year.
Grants are available: automated pellet stoves fitted internally can command up to £600 or 20% of installed cost maximum; biomass fuelled boiler systems can be eligible for up to £1,500 or 30% of installed cost maximum.
Where can I find out more?
The DTI funded low carbon buildings programme provides grants to help with the costs of installing Biomass technologies.
To be eligible for a grant you will need to use a certified installer and products.
Or visit the following sites:

Visit: Energy Saving Trust

Visit: Centre for Alternative Energy

Look for Ourpower Pioneers in the Ourpower Community who have fitted Solar PV systems near you so you can ask and read about their experiences. Then use the Ourpower Directory to find local installers and suppliers - reading about what they can offer and what they have done, before asking a number to consider your situation and to quote. Always, get at least 2 quotes - more if possible.

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