Here's a little German for you: "dunkelflaute" – it translates to dark doldrums, or literally those windless and sunless moments when renewable energy disappears.
No wind for turbines, no light for solar panels.
As the Germans will tell you, these moments are more common than you might think. And unfortunately, they often happen during periods of peak power demand.
Take the heatwave that blanketed the U.S. Midwest and much of the East Coast in June.
On the MISO electricity grid – which covers parts of 15 central states stretching from Louisiana all the way up through Minnesota – grid operators were forced to declare a maximum generation event. That means they ordered every power plant available – even those scheduled for maintenance – to crank out as much electricity as possible to avoid rolling blackouts.
The system was pushed to its limit. Some power plants met the moment, others simply couldn't.
MISO happens to be home to some of the nation's premiere wind power. In fact, the grid has 30 gigawatts of wind capacity—enough under ideal conditions to meet the electricity needs of 20 million homes.
But on June 24, when demand was peaking from soaring temperatures, the wind simply stopped blowing. Of the 30 GW of wind capacity, those turbines produced just 2.8 GW of power. The doldrums indeed.
So what picked up the slack? You guessed it: The coal and gas power plant fleets.
Dispatchable generation, whether you're in Berlin or Baltimore, remains the critical foundation of our electricity system.
