Every year millions of tonnes of food from factories, restaurants, shops and homes ends up in landfills across the country. Here the discarded waste produces a greenhouse gas, which is 30 times more damaging to the environment than CO2. But if one UK company gets its way, we will be turning this rubbish into a valuable resource.
GENeco runs a modern food recycling plant in Bristol. More than 40,000 tonnes of food waste from across the southwest is diverted from landfill and delivered to its plant in Avonmouth every year.
Here the food waste is macerated, then liquefied. The liquefied food waste is pasteurised, and then digested for 20 days to release biomethane, which is burnt in a combined heat and power plant to generate renewable electricity.
Another product of this process is a liquid rich in nutrients that is ideal as an organic fertiliser.
GENeco also produces fertiliser in the form of a solid cake that farmers can store on site and apply to the land when it is best able to take in various nutrients, including nitrogen, sulphur and magnesium. When used as part of an integrated soil-conditioning plan, biofertiliser stimulates microbial activity and improves the condition of the soil and crops.
In addition to providing energy for the recycling plant, any spare biogas can either be injected into the national gas grid or used to run the company's famous Bio-Bug.
The Bio-Bug is the UK's first VW Beetle to be powered by human waste. The waste flushed down the toilets of just 70 homes produces enough biogas to power the Bio-Bug for a year – with, GENeco says, no loss of performance compared with a petrol car. Though it is early days for the UK in the use of this technology, in Sweden more than 11,000 vehicles already run on biomethane produced from its sewage plants.
GENeco's trial of the Bio-Bug has so far proved successful, for biogas supplied both from sewage sludge and from food waste. If the results of the trial continue to look promising, the company hopes, in future, to convert some of its fleet of vehicles to run on biogas. The company sees this green fuel as key to achieving its long-term ambition of being able to transport biofertiliser to farms in trucks powered by fuel generated from the food waste itself.
GENeco was created five years ago to help Wessex Water to become a zero-waste and carbon-neutral company by 2020.
Within two years, in treating half of Wessex Water's sewage sludge, the company was putting no waste in landfill and was carbon-neutral in terms of its energy usage. The company has also worked with the Prince's Trust to create six positions for young, long-term unemployed people to work in the field of renewables. A number of years later, five of these young people are still with the company.
Nicolette Fox is part of the wordworks network.
The Guardian Sustainable Business Sustainability Case Studies contain articles on all the initiatives that met the criteria for the GSB Awards.
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