Ofgem’s E-Serve arm is back in the headlines over its oversight of another green energy scheme in Northern Ireland.

It faced criticism over its performance and role during the inquiry into the Renewable Heat Incentive.

Now E-Serve is in the firing line again thanks to a BBC File on Four programme and articles that allege that companies granted renewables obligation certificates (ROCs) for output from anaerobic digester plants gamed the system, over-claimed and in some instances were paid for non-existent plants.