Holistic approach turns commercial food waste into money

The Holsworthy Biogas power station in Devon, which turns over £5M a year, is proof that a large-scale anaerobic digestion plant can operate economically when commercial food waste is used as the feedstock.

Holsworthy Biogas produces more than 2,200MWh of electricity a month enough to power 8,000 homes. Around 94% of its output is exported to the local grid, with the other 6% powering the plant. The digestate is used as a bio-fertiliser, which is supplied to local farms to avoid the use of chemical fertilisers.

The plant was originally built in 2001, designed to use mostly farm slurry as the feedstock. It was purchased in 2005 by Andigestion: a subsidiary of the Summerleaze group, which quickly recognised that the plant's business model was defective. Commercial food waste could offer markedly greater electricity generation potential and the firm invested to upgrade the plant and its systems accordingly.

Holsworthy can process up to 80,000t of waste a year. This is collected mainly from the south west region, although some comes from further afield. The waste is derived from supermarkets, bakeries, food and juice producers and restaurants. It also includes waste ground grain and sorted domestic waste brought in via an agreement with Viridor and some of Devon's local authorities.

The operation is still growing and the Summerleaze group is still investing in its holistic approach to renewable energy production.

Peter Prior, executive chairman of Summerleaze, said: "The key to optimising performance lies in ensuring that the feedstocks, technology and business model are right. Our research and engineering departments have worked hard to ensure the correct balances are achieved in production and our transport and agricultural departments have established highly effective systems for waste collection and bio-fertiliser storage and distribution. We now have an excellent team working on depackaging out-of-date food."