A larger solution...
Electric power used for computation, generating waste heat.
Electric power used for space or water heating.
Integrate these.
I've already (repeatedly) suggested that we're very close to the point where ~$100 1kw baseboard heaters (or Heater Bars in UK-speak) could be cost effectively replaced by $1000 1kw CPU Arrays, built into the same form factor. The extra cost of the hardware is profitably recovered by the value of the CPU cycles.
Everything is falling into place. Widespread broadband. Auction sites, to sell off the CPU cycles. Coin Mining. Protein Folding for charity to balance supply. Just requires mass production of $100 100-watt CPU modules, to be clicked together. These new economics would re-optimize the design of the CPU Heater brick. Older and cheaper designs might be optimum, maybe.
It's (just about) time.
June-August remains an issue. Not enough land mass and population in the Southern Hemisphere. Of course, Domestic Hot Water is needed year round.