ALSO SEE England Woodfuel Pages
Q: What is woodfuel heating?
A: This is a type of heating that involves burning biomass such as wood pellets or chips in a ‘boiler’ unit to produce heat. In domestic settings, these units can be space heaters such as stoves but higher output boilers can also provide hot water or central heating via radiators. Boilers are quite sophisticated now, and can be fed automatically by screw drives from fuel hoppers. Electric firing and automatic de-ashing are also available.
These heaters can be almost any size, ranging from a small 15kw unit that will heat a private house, to large scale units suitable for heating factories or large buildings, such as the 700kw boiler that heats Worcestershire County Hall.
Q: Why use woodfuel heating?
A: Most renewable energy production is focussed on producing energy in the form of electricity. Heat is also a form of energy. Heat currently accounts for 49% of the UK's final energy demand (BERR 'Energy Trends' December 2007, HMSO), most of which is used to heat households.
By producing your own heat from burning wood, not only are you are using biomass in a highly efficieny way, but you can reduce central heating bills, avoid rising gas or electricity prices and reduce your carbon emissions.
Woodfuel is carbon-lean and it's benefits include:
a) Its potential role in helping to prevent dangerous climate change. That's because it can result in lower nett emissions of greenhouse gases than those emitted by burning fossil fuels. Unlike fossil fuels such as oil, coal and gas, woodfuel produced in sustainably managed forests is 'carbon lean', so the only nett emissions are those caused by the harvesting, transport and processing of woodfuel. That's because the next crop of growing trees reabsorbs the same amount of carbon that is emitted by the current crop being burned, in a balanced, 'carbon-out, carbon-in' cycle. No such balanced carbon cycle exists for fossil fuels, whose emissions are all one-way traffic from the Earth's crust to the atmosphere.
b) It's renewable: Unlike fossil fuels, it is a sustainable, endlessly renewable source of energy - we need never run out of it if it is sourced from constantly replanted trees. In contrast, once fossil fuels have been used, they are gone forever.
c) It's good for the woodland environment: Sustainable management of woodlands for woodfuel production is good for wildlife, biodiversity and woodland health, because the thinning, harvesting and coppicing of trees for woodfuel opens up the woodland floor to the sunlight. This encourages a greater range of plants, animals and insects to flourish than if the woodland were left to become rank, dark and overgrown - a state that foresters call "over-mature" or "under-managed" - and boosts woodland health and vigour.
d) It encourages woodland conservation: Foresters have a saying: "the woodland that pays is the woodland that stays". This means that the prospect of earning an income from woodfuel can give a woodland owner an incentive to keep the woodland in good condition and protect it from dying of old age and neglect. This might involve, for example, keeping out the browsing and grazing animals that would prevent young trees from regenerating.
e) It's good for business and jobs: Woodfuel can generate new business and employment opportunities, often in economically fragile rural areas, and it can offer woodland owners an extra source of income from their trees.
f) It's good for fuel security: Woodfuel reduces our dependence on unsustainable and declining fossil fuel resources, and people who use locally produced woodfuel are shielded from the vagaries and fluctuations of the international oil, gas and coal markets.
g) It can relieve fuel poverty: Woodfuel can help to combat fuel poverty by providing an alternative source of energy in areas that are off the gas grid.
h) It's convenient and simple to use: Modern, wood-burning boilers and stoves can compete on ease of use, cleanliness, efficiency, convenience and maintenance with the fossil-fuelled alternatives, especially if they burn chips or pellets.
i) It's competitively priced: Woodfuel can compete on price with the fossil fuel alternatives.
Q: Can I use biomass heating in a smokeless zone?
A: Yes: Biomass appliances with an exemption certificate can be used in smokeless zones, and the majority of woodfuel boilers are fine to install in smoke free areas.
See www.uksmokecontrolareas.co.uk for a full list of exempt appliances.
Q: Why can I use a biomass boiler in a smokeless zone?
A: Wood fuel boilers run at a very high efficiency (90%+), which means that the wood fuel is converted into heat with very few smoke particles produced.
Q: Are there any grants available?
A: Grants are available to install biomass boilers. Different grants are available depending on your situation. The most appropriate grant for domestic biomass boilers is called the Low Carbon Buildings Gran, for information see: www.lowcarbonbuildings.org.uk/home
Q: Do I need planning permission to install a domestic biomass system?
A: If the building is listed or in an area of outstanding natural beauty (AONB), then you will need to check with your Local Authority Planning Department before a flue is fitted.
Q: What is the cost of installing a biomass boiler?
A: The cost for boilers varies depending on the system choice; a typical 15kW* pellet boiler would cost around £5,000 - £14,000 installed.
15kW is the average size required for a three-bedroom semi detached house
Q: How much do the pellets cost?
A: Unlike other forms of renewable energy such as wind or solar power, biomass systems require you to pay for the fuel. Pellets typically cost between £120 - £180 /tonne and pellets cost less at £50 - £80 /tonne. Fuel costs also depend on the distance from your supplier and whether you can buy in large quantities.
Q: How much woodland do I need to heat my building?
A: If you have a biomass boiler project in mind and you would like to estimate how much woodland might be required to provide fuel for it, this How much land spreadsheet.xls might help.
Combined Heat & Power (CHP)
Q: How efficient is CHP?
A: Because CHP systems make use of much of the heat produced during the electricity generation process, they can achieve overall efficiencies in excess of 70%.
In contrast, the efficiency of conventional coal-fired and gas-fired power stations, which discard heat produced during electricity generation, is typically around 38% and 48% respectively.
Q: What is district heating? How does it work?
A: District heating (sometimes called community heating) is where one central boiler provides heat to several buildings. These might be blocks of social housing, local council offices, a school, etc…
District heating can be provided using the co-generated heat from electrical power generation in a Combined Heat and Power (CHP) installation. This can increase the overall efficiency of power generation by a factor of three or more.
Hot water or steam is transferred around the site in a highly insulated heating main. Each building then has an individual heat exchanger to draw off the heat into the building as required.
District heating is much more common in some European countries than in the UK. In Denmark for instance district heating provides around 60% of heating.
See case studies.