I love (LOVE) geothermal systems ... with the 'minor' issue that they can be a nightmare for backfitting.
I have tried to do it at my home, with some commitment to top-notch consulting, it came down to "virtually impossible" ... "will cost you at least $10,000 more due to drilling problems" ... And, of course, there was the additional cost that the drilling rig would be coming from such a distance away that I'd have to pay for two nights of hotels for the drill crew. (E.g., the Washington, DC, area doesn't have much geothermal / drilling business going on.) Now, in my home, I just finished putting in a SEER16 + with gas furnance back up (fossil fuel system) with investing (time) in reducing leaks & upping insulation to R-50 plus.
Have a shared investment property where I went through something similar. Got a $45,000 estimate for a geothermal system -- the estimate for replacing the entire set up with SEER 16 was about 1/4th that. I estimated that the geothermal would save perhaps $1k/year (maybe) on top of the SEER16 along with reduced maintenance and not requiring replacement nearly as soon. But that $30+k difference could not be made up in a few years ...
Which gets to my question about geothermal. Unless it is associated with new building (or a major renovation) where the cost is embedded in the loan, how can anyone calculated a payoff of just a few years? I love (LOVE) geothermal and would love to install, but I do not see how honest claims of payback can be talking such a short period.
Now, there are "paybacks" that aren't just financial. Such as the zero external footprint of geothermal, reduced pollution, quieter, reduction of hot water heating requirements, etc ... but the financials are not as good as, for example, suggested in the California official's claims in the linked article re Geothermal.
But, the key point is Gladwell's -- we already have technology and approaches that could massively change the entire energy picture. Further R&D could certainly lead to new and better approaches, but this is a sad excuse for not exploiting the tremendous options already in hand.
I used to absolutely love geothermal, but since I discovered superinsulation + air exchangers with heat recovery, I don't think they're worth the money anymore.
Much better to have a house that you can (or almost) heat or cool passively, with maybe just the heat of your appliances enough to keep you warm in the winter AND have 100% fresh air thanks to the exchanger. Uses less energy than geothermal, and less expensive over time.