The Duck Curve: One Picture Explains the Rise of Solar + Storage

Kerim Baran teaches our new “Solar Entrepreneurship” course. Last week we had our first live, interactive lecture. It was lightly attended, fun, and I learned something really interesting: The Duck Curve.

Here’s how Kerim explains The Duck Curve:

Net metering makes a lot of sense in the early stages of solar, I would say until probably five to 10% of homes have solar. So about up until about five, 10% penetration in the grid, net metering is something that utility companies are willing to do without much issues. And that’s because solar production, you know, consumption usually goes up from 6:00 AM till about eight, 9:00 PM in the evening, and then goes down over after people go to bed And when solar production happens, which is usually between 9:00 AM, and let’s say 5:00 PM.

That increasing demand is offset by the solar production. And that starts, you know, when you have 1% penetration in the grid, no problem. But when you have 10% or more, then it starts creating this Duck Curve, meaning you have way more production then consumption. And at some point. When you have, you know, 20, 30, 40% of the homes on the grid producing with solar, you can create some major imbalances and frequency issues and high volt, you know, you’re producing more than you can store.

And that, that causes a balancing issue for the grid. And at that point, you need to integrate lots of batteries to store that excess production.