Severn Trent Water Ltd, a subsidiary of Severn Trent plc one of the largest of the 10 regulated water and sewerage companies in England and Wales has announced that it has started operations at its latest green gas plant in Roundhill near Stourbridge, UK. The new facility uses anaerobic digestion (AD) to turn food waste from local businesses and other customers into biomethane that is then injected into the gas grid.
The site will be able to turn almost 50 000 tonnes of food waste a year into renewable biomethane gas that will be injected into the gas grid network for use in homes and businesses. It is Severn Trent’s second food waste anaerobic digestion plant, following on from the success of the existing plant in Coleshill which has been operating since 2015.
We’re really excited to see the new plant at Roundhill become operational. The process also makes sure that the food waste doesn’t end up going to landfill, with any packaging that we remove at the plant is sent for further energy recovery. We’ve got more than 60 years of experience of turning sewage into clean energy, and we’re now putting that to good use in our food waste plants, said Chris Jellett, from Severn Trent.
The company, which serves eight million people across the Midlands and mid-Wales, has invested heavily in renewable energy in recent years and is now developing this expertise to generate even more clean power. The biogas from the anaerobic digestion is upgraded to biomethane – it is ‘washed’ at high pressure, ‘squashed’ to the same pressure as natural gas and is then ‘tested’ for quality. Finally, an odour is added so it smells like conventional gas.
Testing also includes a review of the energy composition of the gas. Once that has been done, it is finally ‘injected’ into the gas supply network.The new Roundhill site has a permit to recycle 48 500 tonnes of packaged and unpackaged food waste a year.
The plant will produce enough renewable gas to heat 2,700 homes for a year and enough renewable electricity to power 1,700 homes. Renewable energy is a really growing area for us and we currently generate the equivalent of more than a third of the energy we use through renewable sources and have ambitions to increase that to 50 percent by 2020, said Jellet.
Severn Trent is continuing to invest in food waste anaerobic digestion plants, with construction work underway at a third site in Spondon in Derbyshire. That plant is expected to become operational in 2018.
The company generates the equivalent of a third of its energy needs through renewables sources, including more anaerobic digestion plants, small-scale hydro plants, solar farms and wind turbines.
