With wind and especially with solar power, the variable output is always pushing the frequency one way or the other, and that creates a great need for costly balancing services.

Speaking as a flashlight enthusiast…there’s many different ways to get a constant and consistent current. Sure we’d need to scale it up from a pocket-sized device to a whole fucking power grid, but with a big enough driver with the right arrangement of capacitors and all that, you’d easily be able to get a totally consistent current out of wind or solar