Biomass Heating

What is biomass heating?

Simply put, biomass boilers are just big boilers that burn wood rather than gas or oil. You can also get boilers that burn biogas. Funnily enough, these are very similar to normal gas boilers, it’s just that the gas comes from anaerobic digesters and are really only suitable for farms as you need a constant and steady supply of food waste.

How they work

Biomass heating systems generally burn wood pellets, chips or logs to power central heating and hot water boilers. As such, you can install a boiler and connect it to your central heating and hot water system.

For those lucky enough to have a source of biogas (for example from a digester on a farm), there are also models available that run on biogas (like the one illustrated at the bottom of the page).

Models are also now becoming available which also generate electricity from the heat of the boiler. These are called Combine Heat and Power (or CHP) units.

Alternatively, you can fit a standalone stove, burning logs or pellets, to heat a single room. Some can also be fitted with a back boiler to provide water heating as well.

Biomass stoves can also be a convenient means of disposing of forestry by-products or waste wood that might otherwise be sent away for disposal.

Where they work best

Before we get onto where it works best, you will need to ensure that your property is well insulated and draught proof if solar thermal is going to work most effectively.

For a wood fuelled system, you will need a large dry area close to the boiler to store your fuel. Ideally this should be close to where the fuel arrives to simplify delivery. Both pellets and wood chips can be piped directly into the store. Many boilers also have mechanisms to refuel chips and pellets automatically

If you are heating the whole house with a biomass boiler, the internal space you needed is typically rather larger than a domestic boiler, and should be close to the fuel store.

You will need a vent which is specifically designed for wood fuel appliances, with sufficient air movement for proper operation of the stove. Your existing chimney can be fitted with a lined flue, which is relatively inexpensive.

Safety and building regulations may be an issue if you live in an old or unusual home.

You may also need planning permission if the flue will extend 1m or more above the height of your roof, or your home is in a Conservation Area or World Heritage Site and you plan to install a flue on the principal elevation visible from a road. You must also check to find if you live in a smokeless zone.

How much energy they produce

Biomass boilers are usually designed to meet the total heat requirement of your house. They can be used in conjunction with solar thermal systems in which case fuel usage is reduced. Individual room stoves typically supplement traditional heating systems.

What maintenance they need

Biomass boilers do require some maintenance and this includes ash removal, though modern systems may only need this after several days. Obviously you also need regular fuel deliveries, and we have Partners able to ensure that your fuel supplies are maintained.

We do recommend a service visit every twelve months to check on the performance of the system.

Tariff levels

The government has proposed the following tariffs in its consultation on the Renewable Heat Incentive (see here). It proposes that tariffs for biomass heating systems will continue for 15 years.

Government has not said if it will introduce degression for any of the heat technologies, but these tariff levels should continue at least before April 2012.