It's amazing to me there isn't some better way of using this energy in energy intensive industries e.g. electrolysis
Battery storage could earn you more if you discharge at the right moment, but energy prices aren’t negative often enough to warrant the expenses on a battery pack. You could also trade on intra-day pricing differences (buy low, sell high) but I doubt this will be an interesting business case for the average consumer.
Of course large scale battery parks work the same way, but they will have contracts with the grid provider to balance capacity, a more lucrative market.
Large scale electrolysis has the same problem as home batteries: big investment, so you won’t recoup the investment unless you can run the electrolyser often enough. Another issue is that electrolysers can’t scale up or down very quickly, so you can’t respond to capacity issues and get lucrative deals in that market.
The problem usually is that there's a physical cap on how much energy can be transmitted through a grid endpoint, and grids themselves charge a significant portion of the bill, meaning arbitrage only works if the actual price is eg. -14c (the case in my particular location)