Solving renewable energy’s sticky storage problem

When the Sun is blazing and the wind is blowing, Germany’s solar and wind power plants swing into high gear. For nine days in July 2023, renewables produced more than 70 percent of the electricity generated in the country; there are times when wind turbines even need to be turned off to avoid overloading the grid.

But on other days, clouds mute solar energy down to a flicker and wind turbines languish. For nearly a week in January 2023, renewable energy generation fell to less than 30 percent of the nation’s total...