Gas produced from a Suffolk brewery's waste is being pumped into the national grid to heat about 235 homes.
The scheme at Adnams brewery in Southwold harnesses methane from malted barley to produce the biogas through a process known as anaerobic digestion.
The plant will also use local food waste, including leftovers from seven nearby supermarkets.
Adnams said waste from brewing 600 pints of beer could generate enough gas for one home a day.
Adnams Bio Energy, which runs the project with British Gas, said in future it hoped to produce enough renewable gas to power the brewery and run its fleet of lorries.
It added that some waste was also spread as fertiliser on farmland to grow barley for Adnams beer.
It is the first time food waste has been used to generate green gas for the grid, and comes just days after Thames Water and British Gas began to inject biogas produced from sewage into the grid.
Climate change minister Greg Barker said: "This has been an excellent week for progress in renewable energy.
"As well as the waste from making beer, Adnams Bio Energy is taking in food waste from local businesses large and small.
"Adnams Bio Energy is setting a fantastic example in bringing the community together to tackle climate change."
Adnams chief executive Andy Wood said: "For a number of years now, Adnams has been investing in ways to reduce our impact on the environment.
"The reality of being able to convert our own brewing waste and local food waste to power Adnams' brewery and vehicles, as well as the wider community, is very exciting."