But wholesale prices shift significantly by time of day, especially in the spring and fall. California’s wholesale prices dipped to the negatives during the days this past spring, hitting -$26/MWh at one point in April. One can imagine projects that only mine when energy is cheap or Bitcoin is expensive, in places that can take advantage of that price volatility.
There are also a few projects that don’t rely on grid electricity because they’ve provisioned their own energy sources (one creative solution is a shipping container with a data center powered by waste flaring of natural gas at oil wells).
So I’d think the price volatility would make it hard to derive a meaningful calculation of energy use from real-time electricity pricing, rather than real-time computational complexity.