https://techcrunch.com/2021/02/17/geothermal-home-heating-gets-a-30-million-boost-from-bill-gates-breakthrough-energy-ventures/

There’s a low energy solution to home heating and cooling sitting right underneath most houses, but until recently no one has been able to tap it.

That solution is geothermal energy, using the earth’s own heat to provide temperature controlled comfort to homeowners is the mission that Kathy Hannun set for herself while working at Google X (the skunkworks division within Google) and it’s been her goal when she spun out her technology as the startup Dandelion Energy.