{"id":2761,"date":"2026-09-16T08:54:13","date_gmt":"2026-09-16T08:54:13","guid":{"rendered":"https:\/\/reports.electricinsights.co.uk\/?p=2761"},"modified":"2026-09-16T08:54:14","modified_gmt":"2026-09-16T08:54:14","slug":"extreme-heat-puts-pressure-on-the-electricity-system","status":"publish","type":"post","link":"https:\/\/reports.electricinsights.co.uk\/?p=2761","title":{"rendered":"Extreme heat puts pressure on the electricity system"},"content":{"rendered":"\n

Britain has been scorched this summer. June saw more days reach above 30\u00b0C than the whole of the 1980s<\/a>. Kew Gardens recorded a full month without a single drop of rain<\/a> for the first time in its 150-year history. Britain\u2019s infrastructure is feeling the strain from extreme summer heat, and the power system is no exception. June\u2019s heatwave (the second of five so far this year) saw temperatures peak at a record 37.7\u00b0C<\/a>, which sent wholesale prices soaring, and left the grid worryingly short of supply.<\/p>\n\n\n\n

On 23 June, wholesale prices surged above \u00a3500\/MWh, then the next day NESO issued its first ever summertime Electricity Margin Notice<\/a>, asking the market to make additional capacity available for the evening peak. Winter is no longer the only season in which Britain must worry about system reliability.<\/p>\n\n\n\n

Cooling is one source of pressure. Requests for home air conditioning installations more than quadrupled<\/a> during the heatwave. Cooling is rapidly becoming a necessity, as hot weather is already costing Britain \u00a31.2 billion a year<\/a> in lost productivity and 4% of annual learning time<\/a> in England\u2019s schools. If global warming reaches 2\u00b0C, more than one-fifth of Britain\u2019s housing stock<\/a> will require active cooling to protect people from dangerous indoor temperatures. That would only add 2% to today\u2019s annual electricity demand<\/a>, so cooling will have little impact on carbon emissions. But as that demand is concentrated in just a few days a year, it can put a serious strain on meeting it at its peak.<\/p>\n\n\n\n

Extreme heat also reduces the maximum output of power stations and the carrying capacity of network assets. Britain\u2019s networks are the most vulnerable part of the energy system, with local grid faults doubling when temperatures exceed 35\u00b0C<\/a>. Climate change could see temperatures in southern England regularly breach 40\u00b0C<\/a>, pushing transformers, cables and switchgear beyond their design conditions. Gas turbines and solar panels become less efficient as air temperatures rise, while nuclear stations can lose efficiency or reduce output as cooling water warms<\/p>\n\n\n\n

Most parts of the electricity system operate less effectively when it is hot. Their maximum power rating falls by around 5 to 15% when it is 35\u00b0C compared to 25\u00b0C.<\/em><\/strong><\/p>\n\n\n\n

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Low wind generation adds to the pressure. Britain\u2019s wind farm output falls sharply during hot, still weather. During the June heatwave, weak wind generation<\/a> tightened margins just as cooling demand was rising.<\/p>\n\n\n\n

Solar offers some relief, supplying much of Britain\u2019s cooling demand during hot, bright afternoons. The tricky period arrives towards sunset, when solar production falls quickly while buildings retain heat and occupants require air conditioning. Other flexible resources must then ramp up quickly to fill the gap.<\/p>\n\n\n\n

During the June heatwave, gas-fired power stations stepped in as solar output faded, earning around \u00a310 million from balancing the grid <\/a>over four days. Interconnectors provided less support than usual because extreme heat was straining electricity systems across Europe. The handling of that week is now under review following whistleblower allegations about operational decisionmaking and record-keeping. NESO<\/a> maintains that the system remained secure, while Ofgem<\/a> is overseeing an independent investigation.<\/p>\n\n\n\n

Britain\u2019s peak demand will continue to occur in winter for the time being<\/a>, but cooling could create local pressures where household uptake is concentrated and network capacity is already constrained. Better shading, ventilation, insulation and reflective materials can reduce cooling needs, although active cooling will be required as heatwaves become longer and more intense. A growing need to cool homes could exacerbate existing energy poverty, as the people most vulnerable to overheating live in homes that are difficult to cool<\/a> and are less able to afford the upfront and running costs of air conditioning units.<\/p>\n\n\n\n

The ultimate fix is to limit warming itself, because every fraction of a degree avoided will make Britain\u2019s summers less extreme. But the need to adapt to our changing climate is now unavoidable, and the electricity system is no exception.
Futureproofing will require more flexibility, interconnection and heat resilient infrastructure<\/a> to meet a growing demand for summertime cooling.<\/p>\n\n\n\n

The average capacity factor of Britain\u2019s renewables is strongly affected by temperature during the summer months. Data covers the last ten years, and runs to 17 August of this year.<\/em><\/strong><\/p>\n\n\n\n

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Britain has been scorched this summer. June saw more days reach above 30\u00b0C than the whole of the 1980s. Kew Gardens recorded a full month without a single drop of rain for the first time in its 150-year history. Britain\u2019s infrastructure is feeling the strain from extreme summer heat, and the power system is no exception. June\u2019s heatwave (the second […]<\/p>\n","protected":false},"author":11,"featured_media":2778,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[71],"tags":[41,72],"class_list":["post-2761","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-q2-2026","tag-electric-insights","tag-q2-2026"],"acf":[],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t