European Power Prices Turn Negative as Heat Wave Breaks Records
(Bloomberg) -- The first major heat wave of the season broke temperature records across northwest Europe, triggered water shortages in the UK and sent power prices into negative territory.
Driven by a persistent high-pressure heat dome, the scorching conditions raised average temperatures by 9C to 15C above the norm across the region. London hit a May record of 35C (95F) on Tuesday, according to the Met Office.
The system pushed away cloud cover across a wide swath of the UK, leading to unusually sunny skies that intensified the heat while also boosting solar power generation. At its peak around midday on Sunday, solar met almost half of the UK’s electricity demand — the highest ever, according to NESO data. The surge in renewable output weighed on Europe’s power market, pushing hourly prices in France below zero around 1 p.m. Tuesday on Epex Spot.
The searing early season heat is raising concerns about the impact of extreme weather as summer temperatures climb. Longer-term forecasts for the world’s fastest-warming continent show more heat waves in the months ahead, especially as high temperatures drain moisture from soils, meteorologists say.
Month-ahead power prices jumped as much as 12% on Tuesday to the highest since March in EEX data on concerns about hydro availability and nuclear curtailments this summer as temperatures climb in key rivers used for cooling French reactors.
In Italy, where air conditioning is more common, power demand is also rising, with consumption on Tuesday expected to reach 46 gigawatts, the highest since April 7, according to Terna.
While the clear skies under the heat dome have been a boon for solar, they’re having the opposite effect on wind speeds. Below-normal wind generation is forecast this week in Germany, Spain, Italy and France, where generation slumped to about 0.5 gigawatts around 1pm, according to RTE data. It has averaged 7.4 gigawatts so far this year.
The heat is expected to peak Tuesday, before slowly easing toward the end of the week.
“A very hot start to the week,” said Greg Dewhurst, a meteorologist with the UK Met Office. “Record-breaking by day and by night, but a cooler end, especially by Sunday.”
Over the weekend, increased water demand triggered system failures that left about 800 households in Kent and Sussex without water or experiencing low pressure. A burst pipe in the Cotswold village of Bourton-on-the-Water also left nearly 200 households with low pressure. Thames Water is still investigating the cause, but heat waves can damage pipes as demand surges and high temperatures shrink and move soil near buried pipes.
France recorded its hottest May day on Monday, with temperatures in Paris forecast to reach 33C on Tuesday, according to Météo-France.
In France, the heat wave has been directly linked to at least two deaths, government spokeswoman Maud Bregeon said Tuesday on TF1 television. At least five people died from drowning, while others died from heat-related causes during sporting events, she said.
Daytime highs are forecast to reach as high as 39C in Languedoc in the south on Thursday, according to Météo-France. There are amber alerts in 13 departments in the west of the country.
“Before 1989, heat waves occurred on average once every five years in mainland France. Since 2000, at least one heat wave has been recorded every summer,” Météo-France said in a statement.
Amber warnings for high temperatures are in effect for western Spain, where temperatures could reach 38C on Tuesday. Similar alerts are also active for parts of the UK through Thursday, including London, east and southeast England, and the Midlands.
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