Making power generation companies responsible for insulating homes was always a bit of a leap, given they don't have a direct relationship with customers.

Perhaps it is not too surprising, then, that three of the four independent generators subject to the government’s Cesp targets failed to deliver. The honourable exception was Yorkshire-based coal generator Eggborough. 

You might have expected them to try a little bit harder than Intergen, however. The US-based firm, which owns three UK gas-fired power stations, met a paltry 6.5 per cent of its obligation. The firm refused to comment on the figure.

GDF Suez and Drax Power didn’t exactly cover themselves in glory either, each meeting less than 40 per cent of their respective targets by the December 2012 deadline.

A GDF Suez spokesperson said the company had belatedly completed the programme by the end of March.

Meanwhile, Drax is considering legal action against Carillion Energy Services, formerly known as Eaga, which it paid £17 million to take on 100 per cent of its Cesp target. Intergen and Scottish Power were also using Carillion for some of their Cesp work. Nobody at Carillion could be reached for comment.

Drax chief executive Dorothy Thompson said when the deal was announced in January 2010: “Working with Eaga means our obligation can be managed in a very efficient way in what is very unfamiliar territory for us.

“With almost 20 years’ experience of improving the energy efficiency of UK housing stock, we believe Eaga is well placed to assist us in meeting our carbon emissions reduction obligation under Cesp.”

The company is now realising its faith was misplaced. A spokesperson said: “Drax’s competence lies in the generation of electricity… Drax has no direct relationship with domestic consumers and no expertise in delivering energy efficiency schemes to households so we outsourced this service but our chosen provider failed to deliver our obligation.

“We entered into further agreements with additional third parties in order to rectify this shortfall so far as was practicable, but for various reasons we were not able to fully comply by the end of the obligation period.”

The regulator can fine companies up to 10 per cent of annual turnover for their failures, or attempt to negotiate redress for consumers. While the generators await Ofgem’s verdict, they can breathe a sigh of relief on one score: responsibility for the next round of energy efficiency schemes, Eco and the Green Deal, is all on suppliers.