Forget nuclear fusion — Canadian start-up says it can harness the heat emanating from the Earth’s core to create affordable baseload and dispatchable power using proven technologies. Eavor (pronounced ‘ever’) believes it will be able to provide gigawatts of baseload and dispatchable renewable energy anywhere in the world for less than $50/MWh by the end of the decade, making its technology cost-competitive with natural gas and coal. And it has already proven its concepts in a pilot project, Eavor-Lite, that has been operating in Alberta, Canada, since last December. The three-year-old company’s Eavor-Loop solution might sound like pie in the sky — chief executive John Redfern tells Recharge he initially thought it was “the dumbest idea I’d ever heard” (see panel below) — but it is a remarkably simple concept. Drill a deep hole anywhere on the planet and the temperature will rise about 30° C every kilometre down. In certain volcanic hotspots, temperature gradients reach 60° C or more per kilometre. So drill to a depth of 3-5km — as the oil & gas industry sometimes does — and the temperature of the rock will potentially be hundreds of degrees Celsius. Water poured into such a hole, or produced from that hole, would immediately turn to steam — a resource that can turn electricity-generating turbines. Now what if the hole wasn’t a hole, but a closed loop in which cold water — or a similarly behaving working fluid — travels down a 3-5km pipe, then underground horizontally for a few kilometres, up another pipe and along the surface back to the start?
Recharge 28th Oct 2020 read more »