When it's night and the wind don't blow, you use coal and gas as everyone else.
Since this thread is about Germany, and not everyone on HN reads threads in scope, it's worth pointing out that this is not universal.
In most of Texas, for example, the wind blows most fiercely — and regularly — at night. Solar power contributes to the grid during the day, and wind power picks up that generation loss when the sun goes down. I once saw a graph of it from a utility regulator published in a newspaper.
Not every geography is so lucky in this manner. But because this is the global internet, it's important to point out that solar and wind aren't exclusively daytime sources on most of the planet.
What Germany needs is a source of wind that works at night. I've read that Spain imports energy from North Africa. Perhaps a more robust link in that direction is the solution.
Since this thread is about Germany, and not everyone on HN reads threads in scope, it's worth pointing out that this is not universal.
In most of Texas, for example, the wind blows most fiercely — and regularly — at night. Solar power contributes to the grid during the day, and wind power picks up that generation loss when the sun goes down. I once saw a graph of it from a utility regulator published in a newspaper.
Not every geography is so lucky in this manner. But because this is the global internet, it's important to point out that solar and wind aren't exclusively daytime sources on most of the planet.
What Germany needs is a source of wind that works at night. I've read that Spain imports energy from North Africa. Perhaps a more robust link in that direction is the solution.