[glamp]

On the grid there are lots of different types of producers (solar, diesel, wind, nuclear, etc.). Each has its strengths/weaknesses. A big weakness of nuclear plants is that it's very expensive to turn them off. So much so that when electricity demand temporarily goes down (and with it prices), it is actually more profitable for them to continue keep the plant running but pay someone to offset their excess production.

There are people that arbitrage this--moving water up a hill is actually how many of them do it.

This stuff is really confusing. My brother trades electricity and has explained it to me numerous times and it's still a little fuzzy.

[dv_dt]

The problems are also not always technical. In CA I've read articles with descriptions of similar moments where power needs to be shutoff from renewable sources and/or offloaded from the grid, but in part because contracts locked in priority for some fossil-fuel peaking plants over renweable sources.