Last week’s late winter cold snap, which coincided with low wind energy, saw the British and French grid operators just a few steps away from declaring a power-supply crisis.
On March 7, the UK was scheduled to export electricity to France at peak evening demand. National Grid Plc issued a rare warning to the market about a shortage that could not be solved by traditional measures such as asking plants for more electricity or cutting consumption.
The company requested Reseau de Transport d’Electricite in France to return some of the exports due to flow to alleviate the situation. However, slides published Wednesday showed that the French grid refused. RTE stated that it required power and would need to request Emergency Assistance, which is a rare status.
RTE stated that it could not send power unless Britain declares an emergency alert. Slides showed that National Grid instead turned on its reserve coal-fired power plants to help ease the situation.
The fragility of Britain’s energy system was highlighted last week by the closing down of old nuclear and coal plants. The key component of Britain’s energy security strategy is electricity imports via large cables that run under water to European markets like France and Norway. This winter, the UK’s grid was unable to balance when wind output was lower due to cold weather.
Grid data shows that Ireland also limited exports to the UK because it was under the exact same pressure.
National Grid stated in its winter outlook report, that the base case assumed that power imports from Europe were available when demand is met. But that was not the case last week.
Later, on March 7, intraday trades were conducted on the interconnector with France in order to import British goods. The coal reserve was also stopped.
This was the first time that the grid operator had used coal-fired power reserves it was asked to purchase to deal with an historic energy crisis. National Grid stated that it was asked by the government for a reserve extension for next year. However, Electricite de France SA and Uniper SE, as well as Drax Group Plc, all claimed their units wouldn’t be available in winter 2023-24.
This could lead to more government intervention, particularly since the coal reserve was required this winter, according the slides.