The number of anaerobic digestion (AD) plants delivering green gas to the grid has doubled in the past year to almost 90 sites, according to the latest figures from the Anaerobic Digestion and Bioresources Association (ADBA). The industry group’s annual Market Report revealed that in addition to a surge in the number of facilities injecting biomethane into the grid the total number of AD plants in the UK has risen from 424 to 540 in the past year. The group said AD technologies have already reduced UK greenhouse gas emissions by nearly one per cent annually. The investment in new capacity has been achieved despite changes to the Renewable Heat Incentive and wider policy environment, which some within the industry have accused of hampering the expansion of the sector. Charlotte Morton, chief executive of ADBA, said the growth of the sector, in particular in terms of the number of grid connections, demonstrated that “green gas has gone mainstream” over the past two years. “Biomethane [is] now heating around 170,000 homes in the UK without the householder needing to do anything differently themselves,” she said. “Biomethane to grid is a real success story for the Renewable Heat Incentive, and we look forward to the government setting out its plans for the next phase of the support scheme.” The report comes just days after National Grid Gas Distribution announced it has secured £4.8m of funding from Ofgem to support a pilot project designed to boost the use of green gas across the grid. The three-year pilot study aims to update the way gas bills are calculated, to take into account more of the green, lower carbon alternatives to natural gas that are increasingly coming online.