The UK has committed to reaching a target of net-zero greenhouse gas emissions by 2050. The focus and use of renewable energy consumption has been increasing at a steady pace over the last decade. In 2017 alone, the UK achieved (for the first time) over 10% of total renewable energy consumption, making it more popular than traditional oil and coal.
Renewable resources include wind, hydroelectric, tidal and wave, geothermal and biomass.
Biomass energy
Biomass is a renewable energy source that is used to generate electricity. Biomass energy is the UK’s largest renewable resource, accounting for almost 40% of the country's energy consumption from waste and renewable sources.
How does biomass energy work?
Organic matter (from trees and plants) is burned to heat water, creating steam. The steam then puts pressure on a turbine, causing it to turn, powering a generator and creating electricity.
Alternative ways to utilise biomass energy includes:
The use of biodiesel
Burning solid waste
Fermenting alcohol to create bioethanol
Biogas from agricultural and sewage waste
Though this article concentrates on the burning of organic matter.
Why is biomass considered a renewable resource?
The process of defining whether an energy source is renewable or nonrenewable involves analysing the rate of exhaustion, the costs involved and the impact on the environment.
Although considered a renewable resource, the process of generating electricity through biomass does cause greenhouse gas emissions. Depending on the type of biomass that is burned, these emissions may be higher or lower than those generated from some nonrenewable fossil fuels (like gas or coal).
However, plants and trees actively remove and store greenhouse gasses from the atmosphere as part of their natural process. Therefore, it is considered a renewable resource as it can be used as a tool to reduce carbon emissions, so long as it is sustainably maintained and managed.
Biomass energy advantages and disadvantages
Advantages of biomass energy
A renewable resource
The sun is a free resource and plays an active role in the biomass energy collection process. Plants are renewable as they can be regrown, so long as new plants and trees are planted hand-in-hand with the electricity generation process.
Reduced environmental impact
By utilising plant and animal waste, biomass energy is reducing the environmental impact this waste would have if they were simply left at landfill sites.
Steady access to biomass materials
Access to biomass materials will continue to be steady, so long as we are actively replanting and replenishing our stock, unlike fossil fuels such as coal; which are finite.
Lower costs compared to nonrenewable fossil fuels
The cost of collecting biomass materials is lower than the cost of collecting nonrenewable fossil fuels such as oil.
Disadvantages of biomass energy
Not an entirely clean process
Wood pellets are a large source of biomass being burnt in UK-based power stations. In 2018 it was estimated that 7.2 million tonnes of wood pellets were burned as part of the electricity generation process.
Over 80% of wood pellets that were imported into the UK were from Canada and the US in 2018. It is argued that certain aspects, including the creation of emissions during import, is in direct contradiction of reducing greenhouse gas emissions.
Whilst trees and plant life reduce the amount of carbon dioxide in the atmosphere, biomass energy is not an entirely clean process. Burning the waste does release other emissions into the atmosphere.
Higher costs compare with other renewable resources
Whilst the costs are indeed lower than those involved with the collection and use of fossil fuels, they are still higher than other forms of renewable energy, such as wind and water.
Potential deforestation
Biomass is only renewable if stocks are replenished. If this step does not take place, there is the risk of deforestation which will result in the extinction of wildlife.
Biomass energy is a fantastic method of utilising naturally occurring materials and making use of waste. As a renewable resource, it is a far more viable option than relying on finite resources such as coal or oil, however, there are more cost-effective solutions available such as wind or water energy.