Severn Trent Green Power – Food Waste Recycling Partnership

In partnership with Oxfordshire County Council, STGP transforms Oxfordshire’s food waste into green electricity to power homes and bio-fertiliser to restore soil health.

16,600 t
Est. annual reduction in carbon
emissions (tonnes CO2 eq)

9,000
Est. number of people
who benefit directly

Cassington anaerobic digestion facility constructed in 2010
Converting food waste into enough green energy to power 9,000+ homes
Wallingford anaerobic digestion facility commissioned in 2013

Our story

Severn Trent Green Power (STGP) is one of the UK’s largest combined food waste recycling and composting businesses, supporting local authorities and commercial organisations across the UK. We partner with Oxfordshire County Council to treat 25,000 tonnes of food waste collected from the county’s residents every year at our Cassington and Wallingford anaerobic digestion (AD) facilities. These two AD facilities convert food waste into green gas and energy as well as producing a nitrate-rich PAS110 certified biofertiliser that supports local farming.

Oxfordshire County Council was one of the first local authorities in the country to recognise the benefits of food waste recycling and our 20-year contract sees STGP supporting Oxford City Council, Vale of White Horse, Cherwell, South Oxfordshire, and West Oxfordshire District Councils. These services account for over 28% of the recycling and composting achieved across the county.

Our AD facilities process food in a similar way to the human body. Food waste is received and macerated before entering digestion tanks where biogas is released and captured. This green gas is upgraded and injected back into the national gas grid or converted into electricity to be exported to the national electricity grid, helping to reduce carbon and increase the availability of green energy.

Recycling food waste keeps it out of landfill disposal or incineration, produces renewable energy, and returns valuable nutrients back to land (which are lost through incineration). It reduces the environmental impact of the commercial food production lifecycle through renewable energy generation and supports the production of fertiliser that effectively supports local agriculture.

Our Cassington and Wallingford facilities have a combined capacity of 97,000 tonnes per annum and, in addition to food waste from local authorities, we treat solid and liquid food waste from local commercial waste collectors, food producers, and retailers. We are committed to sustainable practices across our facilities and recycle some of the heat produced from the engines to warm our tanks, pasteurisers, and welfare facilities, allowing our sites to be self-sustainable. STGP has very high operating standards and we run our facilities at 99% availability, achieving almost 100% recycling and recovery levels.

As part of the same contract, STGP treats Oxfordshire’s garden waste at in-county composting sites. These sites are designed to convert thousands of tonnes of garden waste from the county’s residents into high-quality compost for use as fertiliser on local agricultural land.

Our ability to deliver high quality services was recognised at the Awards for Excellence in Recycling and Waste Management 2021. We were delighted to win both Organics Recycling Business of the Year, along with the overall Recycling Business of the Year award, with judges impressed by our achievements throughout the duration of the pandemic.

Our advice

Start planning today – The Environment Act – which will shortly come into effect – will mandate separate food waste collections across the country, so it’s important for local authorities to start planning for and securing capacity at anaerobic digestion treatment facilities now.

Talk to us – We are always happy to provide advice and support to any local authority or organisation who wants to improve their access to environmentally sustainable food waste treatment. We can not only help you to process your food waste but also provide logistics services to transport it for processing. STGP arranges site tours, provides educational materials, and organises promotional activities in local communities.

Secure end markets – It’s important to choose a treatment provider who produces a reliable PAS110 accredited digestate product which can be safely spread back to land and who has markets already established for their product.

Consider service reliability – When it comes to food waste, it’s essential that you can always rely on your treatment service provider.

Community engagement – STGP engages in activities to increase and promote recycling such as site tours and video production. One of the most effective initiatives we have supported was a bin sticker campaign with West Oxfordshire District Council. The campaign resulted in a fourfold increase in requests for food waste caddies and food waste volumes increased by 15%.

Participation rates – The five district councils within Oxfordshire, in partnership with STGP, have achieved above-average collection rates of over 2kg per household, per week (WRAP state a national average of 1.5kg). Letsrecycle.com's local authority recycling league table recently announced South Oxfordshire District Council as having the second-highest recycling rate in England in 2021 at 63.6%, with Vale of White Horse coming in fourth at 62.6%. In fact, four of the five highest performing local authorities for recycling in England are STGP customers.

Our metrics

  • Our two Oxfordshire plants generate enough energy to power 9,000 homes for a whole year.
  • This specific contract saves over 3,000 tonnes of CO2 emissions per year compared with incineration. This figure rises to over 16,600 tonnes when compared to landfill.
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