Anaerobic digestion plant opens in England

By Wessex Water | December 04, 2012

Bristol, England’s first food waste recycling plant, which will produce enough renewable energy to power around 3,000 homes, has officially been opened.

The plant, operated by Wessex Water subsidiary company GENeco, will treat 40,000 metric tons food waste from homes, supermarkets and businesses across the south west—preventing it from going to landfill.  

Based at Bristol sewage treatment works in Avonmouth, the plant can produce 10 GWh of energy a year from biogas generated through anaerobic digestion treatment—a process in which bugs break down biodegradable material to produce methane gas. 

Today the food waste plant was officially opened by Defra minister David Heath.

“We see here the ideal balance between good business sense and environmental protection. The GENeco plant is unique by being the first food waste anaerobic plant in Britain to be built in a sewage treatment works. Water companies using their expertise in treating sewage can provide a significant boost to the expansion of waste food anaerobic digestion in this country,” said Health. “This could potentially create thousands of new jobs, generate significant amounts of renewable energy, while solving a major environmental issue in the disposal of waste food.”

We have operated anaerobic digestion at Bristol sewage treatment works for many years and generate around 30 GWh of renewable energy from sewage sludge and produces 250,000 metric tons of high-nutrient fertilizer which is used by farmers instead of expensive inorganic fertilizers. 

The amount of energy produced allows Bristol sewage treatment works—the largest in the south west—to be carbon neutral and self-sufficient from an energy perspective, which helps to drive down operating costs—benefiting Wessex Water customers. 

The GENeco food waste investment will produce even more energy which can be fed in to the national grid. “The opening of the food waste plant builds on the success and experience of using anaerobic digestion to treat sewage sludge and generate power,” said Mohammed Saddiq, GENeco general manager. “Through this investment we will produce significantly more renewable energy, while also providing a sustainable solution for dealing with food waste which traditionally goes to landfill. Dealing with food waste in the this way is better for the environment as it prevents greenhouse gases, by capturing methane which can be used to produce power.”

It is the first time a food waste plant has been located at a sewage treatment works in the U.K.  The plant was built in less than a year and local companies and organizations have contracted to use the facility.

“Anaerobic digestion of sewage sludge is an important part of turning waste material into useful by-products,” said Colin Skellett, Wessex Water chairman. “We are building anaerobic digestion plants at other sites in our region due to the environmental benefits they offer and because they help tackle the problem of growing electricity and waste disposal costs. GENeco provides the opportunity to extend this to food waste so that what we all produce—whether in the form of sewage or food—Is being put to good use and helping to generate renewable energy.”

Bristol treatment works treats waste from around 1 million people living in Bristol, South Gloucestershire and North Somerset.