Comment by ssl-3

When the price of a thing is negative, the entity facing the negative price is being paid to consume it.

We don't have enough automatic integration yet to make it happen, but: Residentially, that'd be a great time to charge millions of EVs and raise the temperature of water heaters. It'd be perfect for getting a head start on heating the glass kiln for Monday morning, or to supplement the used railroad ties and other fuels that might be feeding a lime kiln.

It's pretty easy to think of loads that feature scale and/or quantity, and the ability to switch on and off rather quickly. Even if the negative price event only lasts for an hour. (Even if it only lasts 5 minutes.)