The wind farm which contributed to a massive blackout was awarded nearly £100,000 in compensation after being ordered to reduce its output the day immediately after the power cut, the Telegraph can reveal.
Nearly one million homes and businesses were left without electricity last Friday when Hornsea Wind Farm and Little Barford gas-fired station went off grid within minutes of each other.
After getting back online, National Grid ordered Hornsea to reduce the electricity it supplied the network on Saturday night and Sunday morning entitling its owners, Orsted, to compensation.
Although National Grid, a private FTSE 100 company, insisted the decision to cut Hornsea’s supply was not related to any role it may have played in the earlier outage, the restrictions were the first to be imposed on the plant since it went live in February.
National Grid, which owns the country’s electricity infrastructure, makes millions of pounds of so-called “constraints compensation” payments every year. The system pays out if a supplier with a contract to produce a certain amount of power is then told less is required. While this affects home and business owners’ bills, National Grid insists it is the most effective way of cutting costs because it avoids the need to build more energy infrastructure.
The payout has emerged as National Grid prepares to reveal to energy regulator Ofgem and ministers what triggered the blackout.
The report is expected to focus on how the failure of the generators – one offshore in the North Sea and the other in Bedfordshire – unleashed such a massive power failure across huge swathes of the UK.
An energy expert claimed it is a “striking coincidence” that Hornsea was told to reduce supply in the two days immediately after it apparently contributed to the once in a decade power cut, particularly having never been asked to cut power before.
Dr John Constable, director of the Renewable Energy Foundation, a charity which analyses the green energy market, said “This compensation raises important questions about the way wind farms receive payment for reducing output, particularly so soon after being involved in a blackout which is still under investigation.”
“Our analysis shows there was a drop in system frequency to below normal operating limits on Saturday night, just before Hornsea was told to reduce output. It raises the further question of whether this event was another near-miss.”
A National Grid spokesman said it continuously “balances the system second by second”, adding how limiting Hornsea’s supply was “business as usual” and not related to any involvement in the blackout.
“There are physical constraints on the network and to manage these we can ask generators to reduce their output, in order to maintain stability and manage the flows on the network.
“Generators are compensated via a constraint payment, which is the most economical way to run the system, keeping costs as low as possible for consumers.
“Hornsea One received constraint payments on Saturday and Sunday as part of our business as usual operation of the system. These payments were not related to Friday’s power cut.”
An Orsted spokeswoman confirmed Hornsea was asked over the weekend to reduce production, adding it was a condition of its Ofgem licence intended to guarantee efficiency, security and value for money.
“To put this into context, on Saturday the National Grid made over 1600 such requests to generators of all kinds.”
The National Grid was said to have experienced three “near-misses” in as many months before Friday’s blackout. However, a spokesman denied this and the system had remained in safe limits since.
Duncan Burt, operations director for National Grid, refuted the suggestion that renewable energy made the UK’s energy supply unstable or contributed to Friday’s outage.