Inside the Biogas Boom: Why the UK Is Betting on Anaerobic Digestion
- Jyothi Dondero
- Oct 20
- 3 min read
In recent years, biogas production, achieved via a process of anaerobic digestion, has gained increasing momentum as a sustainable means of creating renewable energy from the vast piles of garbage generated daily across the U.K. According to the Anaerobic Digestion & Bioresources Association (ADBA), there are approximately 756 operational anaerobic digestion plants across the country, together processing around 36 million tonnes of organic waste each year. These facilities have helped transform discarded food, crop residues, and animal by-products into clean, renewable energy that reduces the nation’s reliance on fossil fuels.
How Anaerobic Digestion Works
The process of anaerobic digestion involves multiple biochemical stages, each of which successively breaks down plant and animal waste matter into its most basic elements, including sugars, alcohol, and fatty acids, all in an oxygen-free environment. The final stage of anaerobic digestion occurs when methanogens, a class of methane-producing microorganisms, work to convert the remaining component elements of the waste material into a biogas composed primarily of methane and carbon dioxide. Biogas in this form typically also contains trace amounts of other contaminant gases such as hydrogen sulfide and needs to be further refined before it can be used in natural-gas applications (IEA Bioenergy, 2024).
Reducing Methane and Landfill Waste
The impressive benefits of converting biodegradable waste into biogas are hard to overstate. The waste material that is used in biogas production includes plant and animal food waste as well as animal by-products that would normally end up in a landfill, creating vast amounts of methane gas, whose greenhouse impact far outweighs that of carbon dioxide. Biogas production makes a significant dent in the amount of rubbish that is sent to landfills, thereby reducing the levels of methane that is off-gassed into the atmosphere (ADBA Policy Report, 2024). According to the International Energy Agency (IEA), methane is responsible for roughly 30% of global warming since the pre-industrial era, making its reduction through biogas capture a critical step toward meeting the U.K.’s net-zero targets.
A Self-Sustaining Source of Energy
Most biogas plants are also designed to use at least some of the fuel they produce to run their own processing systems, thereby reducing the demand placed on the regional power grid and making the facility self-sustainable. Many biogas plants also upgrade their product into pure methane gas for sale to electric companies, providing a clean, renewable source of energy that can be used in lieu of traditional fossil fuels (UK Government, 2024). As of 2024, biomethane generated from anaerobic digestion supplies the equivalent of power for nearly one million U.K. homes annually (ADBA, 2024). In addition to electricity generation, upgraded biomethane is also used to fuel public transport fleets and agricultural machinery, further reducing the carbon footprint of multiple sectors (IEA Bioenergy, 2024).
Digestate: The Fertile By-Product
When organic waste is converted into biogas, a residual material called digestate is left behind, composed of the elements that could not be digested as well as dead bacteria and other mineral-rich and nitrogen-rich components. High in nutrients, this leftover material is a powerful and effective organic fertilizer that can be used in place of chemical fertilizers, which can easily contaminate the water table as well as the surrounding soil (ADBA Policy Report, 2024). Farmers across the U.K. are increasingly using digestate as a low-carbon alternative to synthetic fertilizers, helping cut agricultural emissions while improving soil health. According to ADBA’s 2024 policy report, greater use of digestate could help reduce U.K. agricultural greenhouse-gas emissions by up to 6%, highlighting its importance within the circular economy model.
Looking Ahead: Powering Homes with Rubbish
Biogas has long been recognized as an effective and viable alternative to fossil fuels, and in recent years there has been a marked increase in the number of biogas plants across the U.K. However, despite these advances, recent industry reports warn that many facilities face financial uncertainty or even risk closure due to shifting government policies and reduced subsidy support. This contradiction underscores one of the key impediments to the growth of the U.K.’s green energy sector: while innovation continues to thrive, the industry’s heavy dependence on consistent investment and favorable policy frameworks renders the nation’s renewable energy transition plan somewhat precarious. Despite the hurdles, the ongoing expansion of biogas technology reflects a growing recognition that the energy of the future may well come from the very waste we throw away today.
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