The cost of heating remains a major issue across the UK and fluctuations in the price and supply of fossil fuels are adding to the already substantial energy costs.
As homeowners look to save money and with government incentives available to encourage the use of renewable energy, installing biomass boilers into off-gas properties is a now a realistic, practical and cost effective proposition.
In fact, biomass technology can be installed into buildings with many different uses including schools, children’s nurseries, village halls, leisure centres as well as those buildings that were traditionally heated by fossil fuel appliances. Biomass boilers provide a cleaner, more sustainable form of energy compared to the fossil fuel appliances they replace. While biomass boilers are commonly used in off-gas rural locations, they can be easy to live with and models like the Grant Spira require little maintenance.
Biomass boilers are fuelled by wood, and so burn wood pellets, chips or logs to provide an environmentally friendly and convenient way of heating a building, whether a home or commercial building. The fuel is made using waste products from sawmill industries or wood from managed forests (where trees are planted to replace the ones cut down). Increasingly, the most popular type of biomass boiler burns wood pellets.
Wood pellet boilers, such as the Grant Spira, use advanced controls, which regulate the amount of fuel being fed to the burner to match the heat demand of the boiler. The fuel is fed to the burner via an auger connected to the adjacent pellet hopper. This can, in turn, be automatically supplied from a bulk pellet store, which can vary in size. Bulk storage systems provide greater pellet capacity, and purchasing pellets in volume is cheaper than by the typical 10 to 15kg bags. If auger fed, the store needs to be sited close to the boiler. Alternatively, for installations where an auger fed hopper arrangement is unsuitable due to space restrictions, a vacuum system can be used.
Grant Spira units are available in outputs of 6 to 26kW and 9 to 36kW. They come complete with a pellet hopper and feed auger, which automatically supplies the Spira with fuel. There is also the option of increasing the output by utilising two boilers (separately flued) and a central hopper/twin auger arrangement. Models include 12 to 52kW, 15 to 62kW and 18 to 72kW. Using two boilers to achieve higher outputs is very cost effective. When the units are combined their precise electronic burner controls allow both units to modulate as one, down to just 25% of maximum load when the full output is not required.
While many modern pellet boilers will lose up to 20% of the energy produced through waste gases exhausted by the flue system, appliances such as the Spira are condensing and have a secondary heat exchanger designed to capture some of this lost heat energy. Importantly, the Spira is DEFRA approved under the Clean Air Act and also listed on the MCS (Microgeneration Certification Scheme) database.
There is another consideration: Biomass technology is eligible for the Renewable Heat Incentive (RHI). The RHI financially rewards end users for generating and using renewable energy to heat their properties. For example, on a quarterly basis (for 20 years from the date of installation, but paid over a 7 year period), the domestic RHI will pay a tariff of 12.2p per kWh for biomass boilers.
To access RHI payments both installers and products have to be registered with the Microgreneration Cetification Scheme. Installer certification includes assessing the supply, design, installation, set-to-work, and commissioning of renewable microgeneration technologies.
Wood pellet boilers produce ash and do require cleaning and maintenance, however wood pellet boilers, such as the Grant Spira, have a self-cleaning function which, when used with EN Plus A1 grade pellets with low ash content, reduces the need for regular maintenance.
We believe manufacturers of renewable heating technologies should offer comprehensive training and support for installers and end users of these innovative products. This would ultimately improve knowledge in the market place and encourage uptake. Grant UK, for instance, supports installers with the Accredited Installer Scheme, called G-One, as well as free of charge product courses. The training is accessible nationwide, with training centres in Wiltshire and North Yorkshire. Our biomass technical forum, www.grantbiomassforum.com is also an easily accessible place where installers can find answers to technical queries and have discussions with other installers about the technology.
In addition, we offer support for homeowners with a “Living with Biomass” guide. This explains how the technology works and how the customer should look after the appliance, allowing homeowners to make an informed choice when purchasing a wood pellet boiler. The easy-to-follow document can be downloaded here. To make life even simpler we have also produced a series of short films available from our You Tube channel which will tell you all you need to know about biomass, how it works and what you need to consider when servicing and commissioning the Grant Spira boiler.