Comment by ssl-3

It definitely is sometimes difficult to dump power at scale. That's the source of the surplus and resulting negative price.

But it doesn't have to be big. A negative price is still a negative price, even on a small scale.

So, for instance: At home, I have electric hot water. I have some baseboard heaters in parts of the house (that I never actually use, but which I could use). I have central aircon.

All of these things could stand to be automated just for automation's sake, and that's something I'll probably do some day even with the fixed-rate electricity I buy right now.

With automation and price feeds, it's a programmatic no-brainer to switch on the electric baseboards on during the heating season during negative price events and get paid some non-zero amount to get ahead on the temperature game.

During the cooling season, I can probably stand to get paid to supercool the house for awhile.

And during any season: I normally run my electric water heater at a fairly low temperature because that's more efficient, but I'll cheerfully accept money to temporarily raise its temperature.

Or if I had an EV: Maybe I might normally like to keep it at 70% SoC for battery health, but if it's plugged in and the price is negative then I might cheerfully run it up to 85 or 90% or more.

So anyway, it's hypothetically pretty easy for an individual like me to dump a few kiloWatts in a useful way.

A thousand such people make it easy to dump a few megaWatts.

A million such people make it easy to dump a few gigaWatts. (And a million sounds like a lot, until one counts the eventuality of smartly-connected EVs.)