wattso

Yes that’s precisely what I’m talking about. The role I’m envisioning for GSHPs is as backup to ASHPs to reduce those peaks.

What I was trying to get at with the ground rod example is it’s entirely possible that you wouldn’t have to roll out a drilling rig and crew. To zoom about a bit, the main risk for heat pumps is really ugly winter peaks but besides that, ASHPs are perfect 90+% of the time. So the main role I see for GSHPs is backing up ASHPs to shave that peak, and once you scale back their role like that it seems like there’s a lot of ways to cut installation costs significantly.

To jakozaur’s point, there’s plenty of reasons drilling can get cheaper and there’s at least one other company working on it [1]—would love to hear about others! I’m a minimally informed amateur but my intuition is that the way it’s typically done (multiple inch borehole, U-tube geometry) is fairly suboptimal since the diameter is a lot wider than you need it to be just for hydrodynamic resistance and you get losses from the outgoing liquid cooling the incoming liquid. Dropping the diameter should make drilling a lot easier—-you can sink a 5/8”x12’ ground rod with hand tools in the right soil! (you’d still have to figure out how to make the holes meet up but I imagine there are ways of doing this).

[1] https://www.borobotics.ch/

The pretext for the suspension was radar noise.[1]

[1] https://www.nbcnews.com/business/energy/trump-offshore-wind-...