Well the grid needs the most help late afternoon. Which is right when solar starts to ramp down and when people get home and load starts to ramp up.

During solar hours, prices sometimes even turn negative. Literally paying people to take your energy, since solar is so plentiful.

The issue is those late afternoon, early evening hours.

And it’s actually more difficult on power plants. Solar is great when the sun is out, but when it goes away, you need all your power plants running. Issue is, a lot of power plants don’t like to turn on and off. They’d prefer to just run at one speed, all the time. But when the sun is out, we have to turn off power plants, since we’d make too much power. And turning them back on can be a long and expensive process.

And that’s where some of this rhetoric comes from. From a power plant perspective, we go from no-load in the afternoon (all solar), to full load in the late-afternoon/early-evening (no solar). The grid was never designed for this, and it’s having a hard time adapting so rapidly.

Batteries are totally a solution but the technology is super green and not really at a grid scale yet.