At least in Europe, the lowest prices (even negative sometimes) for electricity are when renewable energies are producing a lot (e.g. when there's a storm in the north sea). If bitcoin mines are plugged on the real time market of electricity they would have an incentive to turn on when there's a lot of renewable energy produced. Assuming mines optimize their mining schedules on that, there's a scenario in which it could even help soak up the low prices and push investments into renewables.