Temperatures in the UK recently soared into the high 80s, increasing demand for cooling across Britain and prompting energy company National Grid to call for a restart of a coal-fired power station.

Uniper, the German-based energy group, on June 12 said National Grid called for Uniper’s Ratcliffe-on-Soar coal-fired power plant in Nottinghamshire to begin supplying electricity as extra power is needed during a period of higher-than-normal temperatures. The National Grid Electricity System Operator (ESO) published a market notice Monday calling for additional power to be available to help balance electricity supply and demand.

One unit at the Ratcliffe plant was restarted early Monday, with a second unit brought online later in the day, according to reports.

Monday’s action ended 46 consecutive days in which coal had not been used to generate electricity in Britain. The past weekend marked the first time this temperatures topped the 30C mark. Meteorologists are forecasting a hotter-than-normal summer across the UK, which would push up demand for electricity to power air conditioning.

Market Notices

The ESO has previously issued market notices during periods of increased demand for power, and has contracted with some coal-fired plants to supply more electricity. But additional generation has rarely been needed outside of colder winter months.

Britain wants to close all its coal-fired power plants by October of next year, part of its efforts to meet a 2050 target of net-zero emissions from its energy sector.

Natural gas-fired power plants were providing about 41% of the UK’s electricity on Monday. The heat wave also is impacting wind power, which was providing just 7% of the country’s power. Wind power during the first three months of this year on average supplied about one-third of the country’s electricity, according to government data.

Britain’s power supply has been reduced recently because a subsea power cable—the North Sea Link interconnector—connecting the country with Norway has been limited to half its normal capacity of 1.4 GW due to a problem at an onshore facility in Norway. Norwegian grid operator Statnett said the 450-mile cable could return to full capacity on June 13.

Darrell Proctor is a senior associate editor for POWER (@POWERmagazine).