At least five Westcountry church schemes to install solar panels have been put on hold and one finished job is set to lose thousands in revenue after a costly blunder by the Government.
Churches have not been designated as community buildings by the Department of Energy and Climate Change (DECC) and therefore do not qualify for the higher rate of Feed-In-Tariff (FiT) – the amount paid per unit of electricity supplied into the national grid.
Friends of the 13th-century St Peters Church, in Mevagissy, the Church of England Diocese of Truro and Cornwall and the Renewable Energy Co-operative (R-ECO) have all criticised the decision as a glaring "oversight".
Abraham Cambridge, a systems designer at R-ECO, said it was puzzling because churches are exempt from needing an energy performance certificate (EPC) when being bought and sold.
He said the ruling had left five of the company's Cornwall schemes, including St Eval church near Newquay, in limbo.
"It does not surprise me one bit," he said. "Sometimes I wonder if they have a clue of the disruption they cause to small businesses like ours when their mistakes come out in the wash."
In August DECC amended the rules for receiving solar energy payments to require an EPC rating of band D and above, a massive task for inefficient old buildings unsuited to cavity wall insulation. An exception was made for community buildings and schools as they are notoriously hard to treat and have greater social benefit than private ones.
Garth Sheppard, a campaigner, said it was "only sensible" for the Government to exempt hard-to-insulate buildings such as the Mevagissey church.