The intense heatwave almost caused widespread power cuts, analysts have warned, as grid operators struggled to supply sufficient power to meet demand.
National Grid’s 1-hour forecast for de-rated margin (the difference between available generation and demand) was negative for two hours on 18 July – (this means demand was forecast to outstrip supply). This saw two Capacity Market Notices (CMN) issued – which are automatically issued when the de-rated margin falls below 500MW. These were subsequently cancelled, as the market responded by increasing the level of available generation during the evening peak.
Close to the edge
Analysts at Cornwall Insight said “demand [was] very close to overtaking supply” during July 18 during the extreme heat. The unprecedented temperatures impacted the level of available generation due to lower combined cycle gas turbine (CCGT) efficiency as well as the heat swelling transmission lines – lowering their ability to carry power.
Over the course of two hours last Monday, grid operators were forecasting a 70% chance that demand would outstrip supply, an outcome that would have caused blackouts across the network.
“Crisis averted”
The crisis was averted, as coal plants fired up and interconnector cables began sending electricity from abroad before power cuts could occur. But experts say the UK needs to prepare better for extreme heat.
Here at Priva, we echo Cornwall Insight’s worry that rising temperatures across GB and Europe are a real concern as climate change threatens to make these weather occurrences more frequent.
In response, Priva’s UK & Ireland team believes a focus on energy efficiency and demand reductions is now a national emergency. We are doing all we can to support the built environment market in reducing its demand on the grid – if overall demand is lower, the risk of blackouts is mitigated.
