As coal power stations around the UK close their doors, some are trying out a new technique; mixing coal with biomass.
MIX IT UP
Co-firing is the process used when two different energy sources are burned (combusted) at the same time; in this case, coal and biomass.
By mixing these two sources, it means that we use less coal, which is the dirtiest of all the fossil fuels, giving off large amounts of greenhouse gases and air pollutants, which is bad for the environment and our health, and use more of a cleaner source to make up the difference.
Biomass can come in the form of crops, sewage, wood pellets and other natural sources of energy. Find out more about biomass here.
It’s not as simple as swapping some of the coal we would normally use with some biomass. There are benefits and drawbacks to co-firing with coal and biomass.
PROS AND CONS
- Mixing two energy sources such as these means we are using less of the dirtier energy source (coal), because we are substituting the amount needed with cleaner, renewable biomass.
- We don’t need to build new biomass power stations, which saves time, money and space, as we can use the coal power stations that are already up and running. There might be some changes needed depending on the type of energy source, but nothing to as big a scale as a whole new station.
- Using biomass allows the UK to meet its targets for renewable energy, alongside solar, wind and hydro.
- A lot of biomass needs to be brought in from other countries (imported) because of the large amounts needed. This obviously takes away some of the benefit of using a renewable energy source, as emissions are produced from the transportation of the biomass to the power stations from abroad, not to mention the cost of imports.
- Another con to this co-firing process, is that ideally we would be rid of coal completely, rather than cutting down how much we use. However this way acts as a move towards the right direction. Especially for countries who are continuing to use large amounts of coal in the near future, this is one way of transitioning.
- Using land for growing appropriate biomass means that that land cannot be used for other agriculture uses like grazing for animals or growing food crops. This process could be more sustainable if land that cannot be used for food or grazing is used, and that the land farmed is replanted and regrown. We could also use waste wood chips from industry rather than growing new crops.