The U.K. electricity system is resilient to blackouts and “ahead of the game” in facing cyber threats, the Department of Energy and Climate Change said after a third power station was hit by fire this year.

“Looking at the historical parallels, the system has steadily got more reliable,” Sarah Rhodes, head of energy resilience at the department, told the House of Lords Science and Technology Committee today. “There have been increases in resilience across the whole piece.”

Fires at RWE AG’s Didcot B power station two days ago, at SSE Plc’s Ferrybridge on July 31 and at EON SE’s Ironbridge on Feb. 4 have squeezed the U.K.’s spare capacity when the margin was already narrowing. The gap between supply and peak demand may fall to as low as 2 percent in the 2015-2016 winter from about 5 percent now, the market regulator Ofgem said in June.

“This cluster of events is really unusual,” Rhodes said. “You don’t usually see three fires so close together, so there are all sorts of questions to ask around that. But there is no reason to suspect that there is anything particularly sinister behind this or that it’s any more than just a simple conjunction of events.”

The spare capacity margin predicted by Ofgem compares with more than 30 percent in 2012, according to Credit Suisse Group AG. Four of Electricite de France SA’s nuclear reactors have been shut since August for safety investigations. National Grid Plc, the network manager, is hiring mothballed plants to provide back-up power this winter to boost security of supply.

RWE’s unit 5 at the Didcot B gas-fired plant is due start on Oct. 27, according to the company’s website. The fire affected the separate cooling towers and not the generating part of the plant, company spokeswoman Kelly Brown said yesterday.

Given the predicted low outage time, the effect on earnings and repair cost should be low, UBS said today in a note. The effect on earnings per share should be less than 1 percent, it said.

Cyber Attacks

Power networks and utilities face threats including bad weather, accidents, fires, hostile attacks and technical failures, according to Rhodes. The U.K. system is “pretty resilient when we compare it to international comparators.”

The U.K. is prepared in the event of cyber-attacks from countries such as Russia or China, she said.

“The industry doesn’t start from a position of being unprotected -- quite the opposite,” Rhodes said. “The industry is probably ahead of the game. We are ensuring that there are audits done by the security services of the resilience of each critical piece.”

The energy department, security services and companies are all working to establish the degree of vulnerability and protection of different parts of the electricity system to cyber threats, according to the official.

“It’s like the layers of an onion: you start with the center and you work your way out,” she said. “A lot of mapping is going on as to how the system operates and where all the leaks are.”

To contact the reporters on this story: Alex Morales in London at amorales2@bloomberg.net;

Rachel Morison in London at rmorison@bloomberg.net

To contact the editors responsible for this story: Reed Landberg at landberg@bloomberg.net Tony Barrett, Alex Devine