If I had my own excavator of decent size, it would bring up the question of depth of soil vs temperature. I'm thinking a hole as deep as the excavator can dig. What would the temps be there? (I would like an excavator to play with ?)
... never mind, I see the posted link states they chose a depth of 4' due to this being a sort of boundary between the permafrost (up to +30' depth) and the seasonal frost layer. That's a lot of cold you have up there!
What about heating the water directly with solar (both electrically and solar water heaters >do solar water heaters work up there?), using a large, well insulated storage tank as heat storage, run the loops from the gshp through that? Of course, heat storage will be limited to the size of tank and available power ... not going to work w/o sun.
The wells sound cost prohibitive.
... why is it not delivering?
Sharp and to the point. Caution, semi-rant/venting ahead.
A lot of it lays on the 'used car salesman' mentality of the business owner who installed the gshp. The rest, the equipment just isn't reliable.
A few 'discovered' issues from shoddy installation/service: 1) after several years, we learn the unit has been generating no 'free' hot water because something in the unit was not turned on, 2) ground loops leaking and have to be refilled, 3) the emergency electric heating strips were installed but never hooked up, we found this out with temps in the single digits as the main unit again quit. 4) loud, wakes us up at night - dealer was supposed to place unit in a water tight tray and place on sound insulating pads to lessen noise. He did not. 5) currently, we find the emergency electric heating strips are not installed correctly causing thermal limit switch to activate, limiting heat output when the main system quits, 6) AND, this is very frustrating as our son has dust mite allergies and we always used the very best filters; they did not bother to attach the air handler part of the unit with the air intake part of the ductwork. The unit was simply pushed up against the ductwork and never physically connected (except for some tape). It eventually separated allowing unfiltered air to circulate throughout the house. There is more, but you get the picture.
Some things that come to mind on the equipment side: 1) the heat exchanger, which runs the entire length of the unit and actually heats/cools the air, leaked out all freon. Over $3k to repair, luckily, we had two weeks remaining on the warranty and the dealer covered the cost, even though he did not show up to diagnose/fix the unit until after the warranty expired. 2) we have been nursing the compressor for several years and a tech installed a 'hot start' capacitor to insure it starts. 3) Did I mention how loud the unit is??? This is a major faux paus for a unit that sits inside the house. Good thing we have a loud home theater in the house. 4) It has never delivered in regards to energy savings. The unit has been down nearly all summer and we used three small ac window units (walmart @$130) to cool our house. Our house is very well insulated but at 2000sq. ft., much more than three @$130 window units should cool. Surprisingly, they kept the house cool, and even more surprisingly, our monthly electric bill dropped >$30.
Almost forgot. Our unit used to 'soft start', as in the compressor gently ramped up to speed. It no longer does that.
... end crying.
Be very cautions where you spend your money. Be absolutely, 110% sure, the dealer is reputable and will stand behind the product. You are going to need them.
Surely the tech has grown up becoming more efficient and reliable over the years.