Biomass is one of the easiest renewable technologies to install onto a heating system in the UK, due to the high grade heat the boilers can produce. There is a debate about sustainability of biomass as a renewable fuel source, however as an alternative to burning oil and LPG, biomass is definitely a far more ecological and financially beneficial solution.
The ‘Biomass Cycle’ is very close to being carbon neutral and so the UK Government has targeted people off the gas grid by offering incentives such as the Renewable Heating Incentive (RHI) schemes. It is often said that biomass is not a sustainable option however through the use of managed forests and waste fuels, householders and businesses off the gas grid can move to a far more sustainable fuel and reduce their carbon emissions by up to 90%. With gas prices rising higher and higher, even people with mains gas could potentially see a financial saving with some fuel types. Below is the typical biomass cycle where it can be seen that the only carbon added is during the processing and delivery of the fuel.
When we talk about biomass heating in the UK, the fuel supply for this is predominantly from wood, a solid biomass fuel. However, there are also systems that will burn other forms of biomass, such as wheat, straw, grain and rape meal (bio-product left over from pressing rapeseed to extract oil). A biomass system is not eligible for the RHI if you are burning liquid bio-products or other grains grown for fuel. This is to avoid competition with food production.
The characteristics of the solid biomass fuel play a major part in how the heating system performs. All boiler types require a good quality fuel to operate efficiently and effectively. The key considerations when qualifying the fuel are; size, moisture content, calorific value, density and for wood pellets, mechanical durability. The UK government has adopted the European standards for solid biofuels and solid recovered fuels, which has been published as technical specifications. These have been developed to aid the trading of fuels, not to provide any specific quality for the fuel.
As a rule of thumb, the owner of the boiler should identify the sources of fuel available to them and then decide on the correct appliance that can handle that fuel type. However, flexibility in fuel usage by the appliance is particularly important for wood chip boilers.
The UK biomass market is roughly split into 3 sections, which some blurring between them;
Installed inside the living room in the form of a pellet stove with integrated boiler or a small boiler in a utility room designed to be quiet while running. More info
Small Commercial Biomass Boilers
Predominantly for the small commercial market, ranging from 5kW (for use in highly efficient buildings) through to 200kW for small district heating networks, but most commonly 30-90kW these boilers run on a range of fuels with woodchip, pellet or log boilers in some cases. More info
Large Biomass Boilers
Usually fully automated from fuel store to de-ashing (optional) and can be controlled remotely. This makes them ideally suited for commercial, public sector, multiple occupancy and mixed use developments and community/district heating systems. More info
Accumulator tanks (thermal store)
All biomass systems require the addition of an accumulator tank, which acts as an in-line heat storage battery. They range in size and shape greatly, typically from 200 litres to 5000 litres, and are highly insulated. Click here for further information