In some cases, churches had banded together to use their collective buying power to secure green energy tariffs from companies that bought or produced at least 80 per cent of their electricity from renewable sources, said Tim Gee, campaigns leader at Christian Aid.
A number had saved money but in certain instances this was because the churches had not switched suppliers in a long time, he said.
“The very cheapest electricity supplier is still fossil fuels,” he said, but the churches had still been able to obtain the cheapest available renewable energy tariffs.
The overriding reason for acting, he added, was to send a message to governments and investors that there needed to be a shift away from fossil fuels if the world were to avoid dangerous levels of climate change.