Biomass, also known as bioenergy, biofuel or wood fuel, is quickly becoming one of the most cost effective renewable energy options; projects have been developed in schools, heating systems, hotels and greenhouse systems. Biomass refers to recently living dead biological material that can be used as fuel or for industrial production. It most commonly refers to plant matter grown for use as biofuels, but it does include plant or animal matter used for the production of fibres, chemicals or heat.
Bioenergy does not include fossil fuels, which have taken millions of years to accumulate. The emissions from the combustion of biomass are cleaner than the emissions created by burning fossil fuels, as biomass will only release CO2 absorbed when growing. However, biomass can only be classed as truly renewable or carbon neutral when the rate of planting equals or exceeds the rate of use. Most modern biomass boilers have efficiencies of around 90% and a near zero carbon footprint however carbon savings are dependant on the type of fuel replaced.
There are two main categories of biomass energy: woody biomass and non-woody biomass. Woody biomass refers to forest products, untreated wood products, energy crops and short rotation coppice (SRC). Non-woody biomass is animal waste, industrial and biodegradable municipal products from food processing and high-energy crops.
There are 3 main ways to heat a domestic property using biomass:
- Stand alone stoves providing pace heating for a room can be fuelled by logs or pellets
- Boilers that can be connected to a central heating system and hot water systems
- On industrial scales, large gasification boilers can be used to generate electricity
Biomass is not just burned as fuel; it can be used in a number of different ways.
Low -tech processes include:
- Composting – to make soil conditioners and fertilisers
- Anaerobic digestion – decaying biomass to produce methane gas and sludge as a fertiliser
- Fermentation and distillation – both produce ethyl alcohol (ethanol) used in paint, solvents, nail varnish remover etc.