What is Biomass?

biomass fuel

Biomass is organic matter of recent origin. It doesn’t include fossil fuels, which have taken millions of years to evolve. The CO2 released when energy is generated from biomass is balanced by that absorbed during the fuels production. This is why it is considered to be a carbon neutral process.

Biomass is often called ‘bioenergy’ or ‘biofuels’. These biofuels are produced from organic materials, either directly from plants or indirectly from industrial, commercial, domestic or agricultural products.

Biofuels fall into two main categories:

  1. Wood biomass includes forest products, untreated wood products, energy crops, short  rotation coppice (SRC) e.g. willow.
  2. Non-wood biomass includes animal waste, industrial and biodegradable municipal products from food processing and high energy crops, e.g. rape, sugar cane, maize.


Biomass and your home

There are two main ways of using biomass to heat a domestic property:RED Compact wood pellet boiler

  1. Biomass Boilers connected to central heating and hot water systems. These are suitable for pellets, logs or chips, and are generally larger than 15 kW.
  2. Wood Fire Stoves providing space heating for a single room. These can be fueled by logs or pellets but only pellets are suitable for automatic feed. Generally they are 5-11 kW in output, and some models can be fitted with a back boiler to provide water heating.

Wood Fire Stoves are 80% efficient and are normally used for background heating. They also add aesthetic value in the living area of the house itself. Many wood burning stoves act as space heaters only. But the higher output versions can be fitted with an integral back boiler to provide domestic hot water and central heating through radiators, if needed.

There are many wood pellet, wood chip and log boilers available. Log biomass boilers must be loaded by hand and may be unsuitable for some situations. Automatic pellet and wood-chip biomass boiler systems can be more expensive. Many biomass boilers will dual-fire both wood chips and pellets, although the wood chip biomass boilers need larger hoppers to provide the same time interval between refueling.


Is your house suitable?

You should consider the following issues if you’re thinking about a biomass boiler or stove. An accredited installer will be able to provide more detailed advice.

Fuel: It’s important to have storage space for the fuel, appropriate access to the biomass boiler for loading and a local fuel supplier.

Flue: The vent material must be specifically designed for wood fuel appliances and there must be sufficient air movement for proper operation of the stove. Chimneys can be fitted with a lined flue.

Regulations: The installation must comply with all safety and building regulations.

Smokeless zone: Wood can only be burnt on exempted appliances, under the Clean Air Act. This mainly applies to domestic appliances.

Planning: 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. For more information please see the Low Carbon Building Programmes Permitted Development Rights page.

Costs: Capital costs depend on the type and size of the biomass boiler system you choose. But installation and commissioning costs tend to be fairly fixed. Stand alone room heaters generally cost around £2,000 – £4,000 installed. The cost for biomass boilers varies depending on the fuel choice; a typical 20kW (average size required for a three-bedroom semi-detached house) pellet biomass boiler would cost around £4,000 – £12,000 installed, including the cost of the flue and commissioning. A manual log feed system of the same size would be slightly cheaper.

Running costs: Unlike other forms of renewable energy, biomass systems require you to pay for the fuel. Fuel costs generally depend on the distance from your supplier. As a general rule the running costs will be more favorable if you live in an area that doesn’t have a gas supply.

Payback: This depends on the fuel being replaced and the type of wood fuel being used. It too is more favorable in areas that don’t have a gas supply.

Local benefits: Producing energy from biomass has both environmental and economic advantages. It is most cost-effective and sustainable when a local fuel source is used, which results in local investment and employment. Furthermore, biomass can contribute to waste management by harnessing energy from products that are often disposed of at landfill sites.


Advantages and Disadvantages of biomass


Renewable Energy Source

Biomass energy is generated from organic material, plant or animal waste, which is burned to provide energy, e.g. heat & electricity. Since they come from living sources, these products potentially never run out which makes biomass a renewable energy source.

Better for the environment than fossil fuels

The burning of biomass does release carbon dioxide but captures carbon dioxide for its own growth. Carbon dioxide released by fossil fuel is released into the atmosphere and are harmful to the environment. Many energy sources struggle to control their carbon dioxide emissions as these can cause harm to the ozone layer and increase the effects of greenhouse gases.

Less Dependency on Fossil Fuels

Using biomass as an alternate source of fuel reduces our dependency on fossil fuels which is better for the planet and more cost effective.

Very Easily Available

Biomass is cheap and readily available source of energy. If the trees are replaced, biomass can be a long-term, sustainable energy source.

Reduce Landfills

By burning biomass for energy, we can take waste that is harmful to the environment and turn it into something useful.

Around six million tonnes of wood is wasted by being sent to landfill in the UK each year. This wood could be used in biomass boilers to heat homes and factories etc.

Renewable Heat Incentive

By installing a biomass boiler, you can get paid under the Renewable Heat Incentive, which is a Government-backed financial incentive to promote the use of renewable heat for both the domestic and commercial markets.




The initial cost of a biomass boiler is higher than a regular gas or oil boiler.


Biomass boiler systems are generally larger than gas or oil boilers and require a separate storage area for fuel so therefore a large amount of space is required.



The Renewable Heat Incentive

The Renewable Heat Incentive is a Government-backed financial incentive to promote the use of renewable heat for both the domestic and commercial markets.

The Domestic Renewable Heat Incentive (RHI) is designed to drive forward uptake of renewable heat technologies in homes across Great Britain to cut carbon, help meet renewable targets and save money on bills.

The scheme is open to anyone who can meet the joining requirements. It is for households both off and on the gas grid.

The tariff rate for domestic is set at 12.2p per kWh for biomass boilers. You will receive payment for seven years based on the amount of clean, green renewable heat you make at your domestic property.


The Commercial Renewable Incentive (RHI) payments are for non-domestic biomass heating installations for industry, business and large organizations.

At present the tariff rate for commercial is set at 7.6p per kW/h and lasts for twenty years.