In Germany, they use it to preheat the water for their houses' boilers and radiators.

Intensive management beats economies of scale in a world without fiat subsidy.

Productive heat use is efficient, like our bodies using fat for warmth and energy.

The ones who harness otherwise wasted energy know what's up. That's why @HT can still run S9s. They're not profitable if you have to pay for energy, but the hardware cost is nil so if the energy is free you just split some of the revenue with whoever lets you come in and harness it.