Biomass and wood
Biomass energy is generated from decaying plant or animal waste.
It can also be an organic material which is burned to provide energy, eg heat, or electricity.
An example of biomass energy is rapeseed (yellow flowers you see in the UK in summer), which produces oil.
After treatment with chemicals it can be used as a fuel in diesel engines.
Most electricity generated from biomass is produced by directly burning it.
Animal dung or human sewage can also be collected in oxygen-free tanks called digesters.
Here, the material is If a substance decomposes, it breaks down into simpler compounds or elements. by bacteria that produce methane to form a renewable natural gas, which can then be purified and burnt to generate electricity.
Wood is obtained from felling trees, and is burned to generate heat and light.
Biomass and wood are renewable if the plant material or trees used are replanted and regrown.
Advantages of biomass and wood
- A cheap and readily available source of energy.
- If replaced, they can be a long-term, A sustainable resource can be replaced once used. As a tree is chopped down, many more can be planted to ensure the use of trees can be sustained. energy source.
- They absorb the same amount of CO2 from the atmosphere while growing as they release when they are burned, and so there is no increase in overall CO2 levels.
Disadvantages of biomass and wood
- When burned, they give off atmospheric pollutants.
- Greenhouse gases such as carbon dioxide and methane are released.
- Trees absorb CO2 over many years but this can be released very quickly when burned.
The Lisahally Biomass plant in Londonderry, uses recycled wood to generate electricity.
The power plant was the first of its kind in Ireland.
Over its lifetime the project is expected to save over two million tonnes of wood from landfill sites.