Sustainable Energy

Powering a factory… with potatoes

Anmar Frangoul | Special to
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Boil them, mash them, stick them in a stew. Potatoes, as a hungry hobbit once noted, can be incredibly versatile. And now, in the north of England at least, they are being used as a source of energy.

The 2 Sisters Food Group – one of the UK's biggest food manufacturers – has just opened a new bio-refinery at its Carlisle food processing plant. The facility is powered by potato waste from the facility's pie and mashed potato manufacturing lines.

The plant won't be short of resources: the humble potato is used in roughly 10.14 billion meals every year, according to AHDB Potatoes, a division of the U.K.'s Agriculture and Horticulture Development Board.

"The reason we went for Carlisle was purely because it had a consistent waste stream that was easily manageable," Andrew Edlin, group sustainability director for 2 Sisters Food Group, told CNBC in a phone interview. Edlin went on to describe the bio refinery as a, "next generation anaerobic digester."

Edlin explained that the Carlisle plant makes around 80 million ready meals every year, with potato topped dishes – everything from shepherd's to Cumberland pies – its primary product.

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According to a release, the bio-refinery will generate 3,500 megawatt hours (MWh) per year in electricity and a further 5,000 MWh per year in steam.

The plant's launch is part of an overall sustainability plan that 2 Sisters hopes will add up to 35,000 tonnes of carbon savings annually, helping to cut its carbon footprint by 20 percent come 2018.

As well as helping to save CO2 emissions, Edlin said that the plant had other benefits, including the potential to produce around 20,000 liters of water that could be used in the plant.

The choice of potatoes as a power source might seem strange to some, but this is not the first time that food and drink have been used to produce energy.

Earlier this year CNBC spoke to Celtic Renewables and Bio-Bean, two U.K. companies using the by-products of whisky and coffee respectively to create energy.

For Edlin, plans are afoot for similar plants at the company's other sites. "We have committed to look at all 40 of our factories to see where it's viable (and) we currently have identified 10… (where) we think it is," he said.