January 9, 2025

What Is Dunkelflaute?

Dunkelflaute is a German word meaning “dark wind lull” referring to a period of winter weather with low light and little to no wind. It’s a fairly common phenomenon in Northern Europe, occurring between 50 and 100 hours each November, December and January. While these cold, dark windless spells aren’t necessarily anything new, they’re all the more concerning due to the growing popularity of renewable energy.

As daylight and wind become increasingly limited, solar power and turbines won’t be able to produce as much electricity. To compound the issue, dunkelflaute events coincide with times when people are likely to use more energy. Buildings must turn up the heat to prevent freezing and ruptured pipes, and people will run their lights for longer periods in the absence of sunlight.

Because wind and solar systems can’t generate electricity on demand, with this lack of reliability being demonstrated last November when wind farms could only meet 3-4% of the UK’s power requirements during the morning and evening peak times. Instead, gas-fired plants met around 60% of the demand while the remainder was covered by nuclear and biomass power plants, solar farms and imports.

With coal powered plants now closed and the surge in demand for renewable green energy expected to exacerbate the situation, blackouts may become more likely, and electricity bills may rise. On top of their effect on residents, these changes may hinder public favour of renewable power.

How Dunkelflaute Could Revitalise the Renewable Surge

Dunkelflaute is a concerning prospect for renewables, but it doesn’t have to stand in their way. On the contrary, these events and their potential impact could give new life to renewable power research, which must advance to mitigate dunkelfaute’s worst effects.

Renewables must become more reliable to support wide-scale usage, and fears over dunkeflaute-driven outages may spur that change. They could stimulate operators to install smart transformers across the grid, especially in areas mostly powered by renewables. These technologies would distribute energy according to in-the-moment needs, conserving power and preventing outages.

Dunkelflaute-related concerns could also drive improvements in solar and wind technologies themselves. Some studies have already suggested the possibility of solar panels that work at night, and further research could make them a reality. Similarly, the need for more resilience could drive innovations in other alternative energy sources like nuclear and hydrogen power.

The Role of Flexible Generation in Surviving Dunkelflaute

One particularly crucial technology for surviving dunkelflaute is flexible generation. Regardless of other innovations that may emerge, nature-dependent power sources are intermittent and flexible generating assets such as peaking plants are perfectly positioned to step in and maintain security of supply to the National Grid.

Poor Weather Is a Challenge but Not the End of Renewables

Dunkelflaute poses a significant obstacle, but that challenge can also be an opportunity. These weather events could help extend the clean power surge if governments, businesses, and consumers take it as inspiration to drive renewable energy development.

Renewable power is a complex but necessary issue. Enabling it nationally will require addressing challenges like dunkelflaute, but success in that endeavour will enable needed long-term improvements.