Biomass – the natural alternative to fossil fuels…
Biomass boilers burn logs or wood pellets to provide all your heating and hot water needs, replacing oil, gas or electricity. This can save you money – and is kinder to the environment, since growing wood for fuel forms a closed carbon cycle (the CO2 released by combustion is balanced by the absorption of CO2 required for new growth). Wood pellets are a widely available fuel sourced from sustainable forestry.
Wood pellet boilers are in many ways similar to an oil or gas boiler. They stop and start automatically in response to your heating controls and thermostats. Whilst the boiler itself may often be not much larger than a floor standing oil boiler, some extra space will be required to store the wood pellets, which are delivered by the tonne (split into 10Kg bags) on pallets.
Most people are glad to be rid of the dreaded oil tank, and are fine with loading 10Kg bags into the boiler’s integral pellet hopper (the annual fuel requirement is often 2-3 tonnes per year, and pellets are approximately £260/tonne), though large auto-feed pellet silos can be installed which are refilled perhaps once a year from a delivery vehicle.
Wood pellet stoves (which are optionally available with integrated boilers) make a stylish addition to a living space, providing a warming focal point in a kitchen.
The Government’s Renewable Heat Incentive (RHI) encourages householders to choose biomass boilers rather than fossil fuelled alternatives, and payments received by householders from the scheme often exceed the installed cost of the boiler.
If you would like to benefit from the RHI scheme but would prefer to use logs rather than pellets, then you might wish to consider a log gasification boiler.
These highly efficient appliances are designed to be run unattended for 24 hours or more. Light some kindling, load the boiler chock full with wood, and walk away – returning perhaps one or two days later to repeat the process. The boiler automatically controls the rate of burn to maintain the water temperature in a large ‘accumulator tank’, which in turn supplies heat to your heating and hot water system. These systems take up more room than a pellet boiler – they are usually located in a garage or outbuilding – and can make incredibly good financial sense if you have your own supply of wood.
Dry wood (20% moisture or less) must be used in all log burning appliances. In practice this will usually mean that wood has been dried outside (under cover) for at least a year, or kiln dried. A moisture meter can be used to check. Wood pellets should conform to the European EN plus A1 standard. Finally, it is important to have your appliance installed and maintained by a qualified and accredited installer, so that you can be assured it will provide warmth safely and efficiently, as well as naturally, for many years to come.
Celtic Renewable Energy is a family-run MCS accredited renewable energy installer operating from off-grid premises near Launceston, which has been installing renewable energy systems since 2001.