A couple of years ago this forum had an active thread on Dandelion Energy’s geothermal business (http://www.greenbuildingtalk.com/Forums/tabid/53/aff/13/aft/84604/afv/topic/Default.aspx). I don’t see any comments here since, especially from Dandelion customers. So I thought I’d add mine, as at least a small down payment for the helpful answers others have given to my newbie questions. I contracted with Dandelion about 18 months ago to replace my existing propane-fueled forced air furnace. At the same time, I was also doing a gut renovation (including substantially tightening the building envelope) and an addition on my home. That meant installing all new ductwork as well as the geothermal system. The local geothermal installer Dandelion partnered with (American Heating & Cooling in Poughkeepsie, NY) agreed to also install that new ductwork, separately from my contract with Dandelion. Both Dandelion and American completed their work for the quoted prices with no surprises. The final system design incorporated two vertical wells, supporting two heat pump units. The wells were done by a conventional drilling rig, with the usual mess and disruption that implies. The drilling caused my domestic water well to turn cloudy for a couple of weeks, but it cleared up and has remained clear ever since. Our construction delayed the installation of the ductwork and heat pumps. Once underway, it proceeded smoothly. Both Dandelion and the local installer were very responsive to questions and have continued to be so now that the system is in service. Not that there have been many questions: I’ve been using the system as my sole cooling and heating source for six months, and have boringly little to say other than it’s working perfectly. At system startup in early September when there was still some cooling demand it was comfortable and trouble-free, and likewise all winter so far with heating. I’m not able to make a systematic comparison of running costs/energy consumption vs propane. Even if I were, it would be complicated since at the same time I switched to this system my house changed in many other ways; and it’s been a fairly mild winter. So I’ll just note that in past years using propane heat, my grid-tied PV system almost exactly covered my typical electricity use over the course of the year. So far since switching on the geothermal—during low season for PV production—I have gotten monthly power bills showing usage in excess of my PV production, but the highest billed amount is much less than I was paying for propane in an average winter month in the past. And this is despite the fact that my house is now bigger and I’ve been away less this winter (and therefore setting the heat back less). I can’t yet speak to performance through the peak summer months (which I expect to be fine, given that this is a heating-dominant climate) or to the long term. But for the time being, I can report that I’m completely happy with this system and with my experience with Dandelion and their local installation partner.