The sun had a busy day last week. On Saturday, for a few hours around noon, Germany (the entire country) managed to meet half of its total demand for electricity from solar power alone. That's 22 gigawatts, or about the capacity of 20 nuclear reactors.
Nuclear reactors may not be the best milestone for German power output. Germany is currently in the process of shutting down all of its nuclear power plants, with eight going offline immediately and the remaining plants scheduled to be decommissioned within ten years. In order to keep the lights on, the country is having to invest more in other power sources, like solar. The 22 gigawatts of solar that Germany hit last week is actually a world record: no other country has ever produced so much solar power all at once. This should perhaps not be too surprising, considering that Germany has nearly as much installed solar capacity as the rest of the world combined.
While this is certainly a huge milestone, it also highlights one of the problems with solar power: Germany hit this number at noon (when the sun is the strongest) when virtually the entire country was free of clouds, and how often does that happen. As appealing as solar, wind, and water power are, it's still necessary to have some stable sources that can produce electricity continuously, and so far that's meant either nuclear or fossil fuels. Realistically, this is probably going to be the way that it has to stay, at least until we get those space-based solar power stations up and running.