Biomass can save energy and money
Have my neighbours done this?
What is it?
Biomass is a solid fuel (logs, wood chip or pellets)
What will it save me?
Biomass is considered carbon neutral so it saves on carbon emissions
How do I get it?
You buy it by weight (kg or tonnes) from a local fuel supplier
What does it cost?
Costs around 6-7p per kWh (2013) depending on moisture content
What are the technical details?
Energy from biomass is the oldest and globally probably the most widespread form of fuel. It is essentially derived from plant material, typically trees, but also from plants grown specifically to use for fuel.
In its basic form, it‘s been used in most homes for many years on open fires as a cheap form of heat, burning waste wood to produce heat. More recently it’s become a very desirable focal point for sitting rooms, particularly when logs are burned in an enclosed stove. Whilst open fires waste most of the available heat through the chimney, modern enclosed stoves are particularly efficient.
Biomass also includes other processes that convert to the basic plant material into a more convenient and usable form. Through a process called anaerobic digestion, plant material and food waste can be turned into a biogas which is used directly to power a generator or in a boiler to create steam to produce electricity from a generator.
Plant material is also used to produce a type of oil used as an alternative to petrol and oil. In some cases a workable fuel oil can be produced from the reclaimed vegetable oil discarded from restaurants.
Some types of modern central heating boilers have been designed to burn wood products such as wood chip and wood pellets in a very efficient and controllable way. They burn the fuel at high temperature to create a clean exhaust gas to satisfy the requirements of the Clean Air Act so they can be used in “Smokeless Zones”.
The fuel is contained in a hopper in the boiler or in a large adjacent hopper with a screw feed into the combustion chamber. They are temperature controlled with fan assisted combustion and can even be automatically ignited. Efficiencies are comparable to modern high efficiency gas and oil boilers.
Biomass isn't carbon free since plants are largely made up of carbon and hydrogen and when they burn they release carbon dioxide and water vapour the same as fossil fuels. However, they are termed “carbon neutral” because the carbon dioxide produced is largely absorbed by new plant growth which becomes the next biomass fuel.
Replacing a solid fuel heating boiler with a biomass boiler will reduce your carbon footprint considerably with no appreciable increase in fuel cost and a lot less inconvenience.