How does anaerobic digestion generate biogas?
At Good Energy, we use biogas both in our 100% renewable electricity supply, and as part of our green gas product.
But what is biogas and how is it generated? Read on to find out.
What is biogas?
Biogas is different from ‘natural gas’ which is extracted from rock via drilling or fracking.Instead, biogas is generated from organic matter and contains around 60% methane and 40% carbon dioxide.
It is made from a process called anaerobic digestion (AD), where microorganisms break down plant and animal products in a sealed, oxygen-free tank.
Refining the biogas and removing the carbon dioxide creates biomethane, which can be pumped into the public gas grid and used in the same way as natural gas. 10% of Good Energy’s green gas product comes from biomethane.
Biogas can also be burnt to generate renewable electricity. This currently makes up over 40% of our renewable electricity fuel mix.
How does anaerobic digestion work?
Organic waste including plants, food waste and manure is fed into a sealed tank, where it can be broken down by bacteria in an environment with no oxygen. The bacteria produce methane amongst other gases, which gets pumped off as biogas.
Solid or liquid material left over from the process is called digestate. This can be used by farms as crop fertiliser, livestock bedding or as enrichment for soil due to the high nutrient content. In this way, anaerobic digestion becomes part of a circular renewable system.
Good Energy’s position on sourcing biogas
We aim to source biogas in as sustainable a way as possible, by buying from generators with high environmental standards. We follow five key principles, which you can read about further in our biofuel procurement policy. These include:
- The biofuel must be either renewable or from waste, with transportation kept to a minimum.
- Ue of energy crops must be kept to a minumum, and only from managed, sustainable sources
- Where animal waste is used, high welfare standards must be met.
Is biogas an important part of the UK fuel mix?
Biogeneration is a hugely important part of the UK fuel mix, and is a key part of the UK’s strategy to have a 95% low carbon electricity grid by 2030. This is because, unlike wind and solar electricity which vary with the weather, biogeneration can provide a consistent low carbon power baseline.
At Good Energy, we match the power used by our home and business customers with renewable electricity from our community of generators in over 90% of hourly periods. Having around 40% of our electricity sourced from biogeneration helps us to achieve such a high hourly matching score, and proves that the UK as a whole can move away from fossil fuel generation and fully embrace renewable energy.
