Europe’s energy security threatened by cloudy and windless days
Europe’s energy security is being threatened by prolonged periods of low wind and solar output, something that’s also driving extreme market volatility, according to Wood Mackenzie Ltd.
Bouts of cloudy and windless days – conditions known as “Dunkelflaute” – are most common in Europe between November and January, typically fueled by high-pressure weather patterns that bring cloudy skies and low wind speeds. Curbed renewables generation during these periods has forced the region to turn to coal or costly gas-fired plants to meet its power needs.
Europe’s energy markets will be exposed to 1.6 Dunkelflaute events on average a year, according to a study by consultant Wood Mackenzie. Northern regions, particularly those reliant on offshore wind, face the greatest threat, it said.
It’s a reminder of the risks faced by Europe’s shift to clean energy to meet climate targets, and the volatility it brings. Because solar and wind farms are dependent on weather, unfavorable conditions can sometimes drastically cut electricity output, meaning fossil-fuel plants are needed to meet demand. But at other times, renewables can produce too much power, causing negative prices.
The critical vulnerabilities are among the issues policymakers should look at, Wood Mackenzie said.
“What should really focus policymakers’ minds is our finding that the coldest days are disproportionately associated with low wind output,” said Matthew Campbell, a senior power analyst at Wood Mackenzie. That’s “raising the risk of tight supply during periods of increased demand and highlighting the increasingly essential role of targeted capacity mechanisms in market design.”
The study found that prices seen in Germany during two Dunkelflaute events last year were enough to generate more than 50% of the wholesale revenues of gas plants that fire up when demand exceeds supply.
During a single Dunkelflaute event in November, coal and gas generation boomed dramatically, with German imports averaging 10.5 gigawatts over three days and intraday prices spiking to $937 a megawatt-hour, it said.