Electricity is the main cost of mining, so miners compete in minimizing their electricity costs in order to maintain profitability, including by co-locating mining facilities with point sources of underutilized power (e.g. remote dams). The sources like this, hydroelectric and natural gas flares, the profitable mining electricity rate is regularly competed below the fuel cost of e.g. coal power. So anyone buying coal to mine Bitcoin is losing rather than making money.
E.g. in this example it’s currently hovering around the cost of natural gas: https://www.forbes.com/sites/robertanzalone/2020/08/13/bitco...
> As both the cryptocurrency markets and the power markets are constantly fluctuating, we do whichever is more profitable at any given time - either sell the generated power or mine crypto with that power.