Potato-powered food factory

One of the UK’s largest food manufacturers, 2 Sisters Food Group, is implementing an ambitious ‘Feeding Our Future’ sustainability plan with aim of delivering 20% carbon footprint savings. Part of this plan involves starting up a potato-powered energy plant.

The new biorefinery at 2 Sisters’ Cavaghan & Gray chilled-food factory, based in Carlisle, is said to be the first waste-powered plant of its kind in the world to be used in food manufacturing. It uses four patented anaerobic digestion processes which are linked to extract gas. When fully operational it will produce 3500 MWh/year in electricity, equivalent to the average annual electricity use of around 850 UK homes, and generate around 5000 MWh/year in steam.

The energy and steam will be used to help power the Carlisle factory and slash its carbon footprint as the first step in an energy transformation project which will see biorefineries developed at up to ten 2 Sisters factories over the coming three years. Following these initial installations, the energy-from-waste plants could be installed at all 43 factories owned by the 2 Sisters Food Group.

The four-storey-high biorefinery at Carlisle will be powered using potato waste arising from the plant’s mashed potato and pie manufacturing lines. Diverting this waste to power production will help 2 Sisters meet its goal of ensuring zero waste to landfill by 2017. The residual waste left after the biorefining process has been completed can also be re-used as fertiliser — completing a circular journey that could take it back to one of 2 Sisters’ 700 farms and away from landfill.

When all the biorefineries are installed, the group expects to make 35,000 tonnes of carbon savings a year. It will also cut 20,000 lorry journeys that would have been used in removing waste, which will now be reprocessed to generate energy.

The biorefineries are being run by renewable energy expert H2 Energy in partnership with 2 Sisters Food Group.