Market sources told Utility Week that power prices softened following the news reports, which has eased concern that further delays to the full return of the fleet might tighten supply margins and raise the risk of blackouts this winter.
The nuclear operator lost 2.5GW of nuclear capacity over the summer after a crack was found in a boiler at Heysham-1. As a safety precaution all units of the same design were removed from service for safety inspections.
EDF Energy initially gave a mid-October restart date for its Heysham-1 and Hartlepool nuclear power plants but later delayed the returns saying it would instead opt for a “phased return” between the end of October and the end of December 2014.
In addition to the nuclear outages, the UK lost SSE’s fire-damaged Ferrybridge coal-fired power plant earlier this year, prompting National Grid to take extra measures to guard against the increased risk of blackouts, and causing market prices to rise.
Further delays to the nuclear fleet return could have pushed prices higher on the power market, and further losses are still expected should the inspections continue on schedule, UK power traders said.
The outages will still cause EDF Energy heavy earnings losses of around £150 million for this year, according to analysts.
EDF Energy chief executive Vincent de Rivaz said in Paris the company would take a hit of 4-5 per cent on its nuclear output for the year, in line with analyst expectations, but that the units would return with no negative implications for future lifetime extensions, according to reports from Bloomberg.
A spokesperson for the company said that no new update is currently available.