When the sun shines and the wind blows, Germany’s solar and wind farms start operating. For nine days in July 2023, more than 70 percent of the electricity generated in the country was produced by renewable energy. Wind turbines may need to be shut down to avoid overloading the power grid.
But on some days, clouds weaken the sun’s energy, causing flickering and causing wind turbines to shut down. For almost a week in January 2023, renewable energy generation fell to less than 30% of the country’s total electricity generation, with gas, oil and coal power plants coming back online to fill the gap.
Germans call these periods dunkelfrautenmeaning “dark doldrums” and can last for more than a week. These are a major concern for recession-hit regions such as Germany and parts of the United States, as countries increasingly pursue renewable energy development. solar Wind power and energy combined account for 40% of total energy generation in Germany and 15% in the United States, and as of December 2024, both countries are on track to achieve 100% clean energy generation by 2035. I have a goal.
The challenge is how to avoid power outages without relying on reliable but global warming fossil fuels.
Solving the problem of variability in solar and wind energy requires rethinking how we power the world, moving away from power grids that turn fossil fuel plants on and off to match energy demand, to shifting energy from fluctuating energy sources. need to transition to a grid that converts sources into a continuous electricity supply. The solution, of course, lies in storing energy when it is abundant and making it available when it is scarce.
However, today’s increasingly popular energy storage device, lithium-ion batteries, is cost-effective only for compensating for fluctuations in sunlight or wind, not for days of windlessness. Also, decades-old methods of storing electricity by pumping water upwards and recovering the energy as it flows back down through turbine generators typically only work in mountainous regions. The more solar and wind farms are installed around the world in an effort to move away from fossil fuels, the more mature solar and wind farms that can cover more areas and store energy for at least eight hours at a time and for up to several weeks will emerge. Cost-effective technology is increasingly needed.
