I believe the key to decentralizing POW is to use the heat generated for other purposes. ASIC machines in a factory can't use that heat. ASIC machines in a residence can provide heat and generate revenue at the same time.
This way even if the cost of mining is greater than the reward people are still going to mine because they were going to use that heat anyway.
This would create a situation where the decentralized mining in residences could massively undercut ASIC machines in a warehouse, vastly increasing decentralization.
You don't think that heat generated in a warehouse could also feasibly be funneled in a way to be useful as well?
AFAIK, the only profitable mining farms in the Netherlands are attached to greenhouses, which would otherwise burn gas for heating.
On a global scale, the cheapest energy is in remote mountainous areas that have hydro power but little industry or population. So there would be little demand for heat there.
Eh, not really. Who pays for heat? The vast majority of people paying to heat air are homeowners.