The UK will need to increase biomethane production around tenfold by 2050 if it is to meet projected demand under future net zero scenarios, according to a new briefing from the Parliamentary Office of Science and Technology (POST).
The briefing highlights anaerobic digestion (AD) as a key technology for reducing emissions from both the waste and agricultural sectors by capturing methane from organic waste streams and converting it into renewable gas.
The UK currently has around 750 municipal, commercial and agricultural AD plants producing an estimated 21 TWh of biomethane each year, with roughly 7 TWh upgraded and injected into the national gas grid.
However, one of the National Energy System Operator’s Future Energy Scenarios projects biomethane production will need to reach 64 TWh by 2050 to support the UK’s decarbonisation pathway.
The publication comes as the House of Lords Environment and Climate Change Committee calls on the Government to assess whether AD infrastructure is expanding quickly enough to handle increasing volumes of separately collected household food waste following the introduction of mandatory weekly collections across England.
At the same time, the Committee has urged ministers to strengthen oversight of fugitive methane emissions from digesters and storage tanks, including considering mandatory leak assessments across all AD sites.
The need to expand the UK biomethane sector was outlined , when a European study showed that, despite biomethane capacity growing by 37% in the EU between mid-2023 and mid-2024, the UK has stagnated in comparison.
Trade group the Anaerobic Digestion and Bioresources Association (ADBA) was prompted to call for the UK government to confirm a timetable for including biomethane in the UK Emissions Trading Scheme to unlock investment.
Under the scheme, biomethane supplied directly to industrial sites receives a zero-emissions factory. However, biomethane injected into the gas grid is treated as standard fossil gas. This means corporate buyers cannot claim it as a net-zero fuel to lower their reported carbon footprints.
At the time, ADBA Chair Chris Huhne said he was “mystified” that the government was being so slow to address the situation.
Example of an AD plant configured to produce energy and biofertiliser from biowaste feedstock from the 2011 Anaerobic Digestion Strategy and Action Plan. ©Department of Energy & Climate Change
For the industrial gas sector, the expansion of biomethane production could also increase supplies of biogenic carbon dioxide (CO2).
Upgraded biogas consists primarily of biomethane and CO2, with the separated CO2 offering a renewable feedstock for food, beverage and industrial applications where captured biogenic carbon is increasingly sought as an alternative to fossil-derived sources.
Alongside renewable gas, AD plants produce digestate, a nutrient-rich biofertiliser that can reduce reliance on conventional nitrogen, phosphate and potassium fertilisers. The briefing notes that digestate can help recycle nutrients back into agricultural soils, although environmental performance depends on feedstock quality and appropriate management practices.
Food waste remains one of the largest untapped feedstocks. According to the briefing, households generate 58% of UK food waste, while between 80 kg and 100 kg of food is wasted per person annually.
Processing food waste through AD produces much lower greenhouse gas emissions than landfill or incineration while recovering both renewable gas and fertiliser.
However, POST also outlines several challenges facing further deployment. Biomethane production remains more expensive than natural gas, creating uncertainty over the most effective policy framework for accelerating investment.
Researchers cited in the report point to ongoing debate over whether expansion should rely on stronger state support through a circular economy model or a more market-led approach focused on renewable gas production.
The briefing also highlights concerns raised by charities and environmental groups that incentives for AD could unintentionally divert edible food away from redistribution towards energy recovery.
Others argue that greater use of purpose-grown energy crops may compete with food production or land uses capable of delivering larger climate benefits, such as woodland creation or solar generation.
Many of the risks and opportunities associated with biogas and biomethane will be discussed at the , which commences today (8-9 July).
