It's good to see a national gas company taking the lead in renewable energy. British Gas in the UK has announced a new pilot scheme with Thames Water and Scotia Gas Networks to build a plant that will clean biomethane gas harvested from human waste and inject it back into the grid for use in kitchens and heating.
Biomethane is created when bacteria known as anaerobic digesters break down organic material such as human or animal waste, food and household waste to produce a thick, odorless waste plus methane. The waste solids are used for fuel or fertilizer and the process can also be used to generate electricity. In a three-prong approach, spare biogas from the process comprised of methane and a mixture of gases can be cleaned of impurities, upgraded to grid specifications, and an oderant with a natural gas smell applied, before injection back into the gas grid for end use by customers.
Thames Water already harvests raw biogas from sewage processing so the new plant at Didcot sewage works will simply clean the gas and return it to the grid. It's estimated that since the infrastructure is already in place the first flow of gas into the grid could occur in summer 2010 to 130 trial homes in Oxfordshire. The cycle itself could take as little as 23 days from start to finish and British Gas say customers will not be able to tell the biogas from natural gas.
One of five biomethane demonstration projects announced by British Gas, it is likely to be the first in the UK to inject green gas into the grid following Government incentives for companies that pursue renewable energy sources. The UK has committed to 15% of its energy from renewable sources by 2020, and biomethane will make a contribution to decarbonizing the gas grid by delivering renewable heat to households through existing gas infrastructure. A survey by the National Grid suggests that biomethane could contribute at least 15% to the domestic market by this time.
"These five projects demonstrate once again British Gas' leadership in renewable energy," said Gearóid Lane, Managing Director of Communities and New Energy, British Gas. "By making early investments in biomethane we intend to drive forward the opportunity to deliver green gas to our customers."