Summer Heatwaves Are Rewriting the Rules for Britain's Power Grid

Summer Heatwaves Are Rewriting the Rules for Britain's Power Grid By City A.M - Jul 10, 2026, 2:00 PM CDT Neso has warned of a possible 1.2 gigawatt shortfall during Thursday evening's peak demand, its second such warning in two months. Wind power supplied just 6.6 percent of Britain's electricity Wednesday, pushing the grid to lean on gas, nuclear and imported power. France has cut nuclear output as reactor cooling water runs too hot, threatening the emergency supplies the UK relies on.