Nothing will ever be truly zero cost, but those costs can be minimal.
A geothermal system for your house involves "transporting energy to your home" but the distances involved are so minimal that once installed it's next to nothing.
> Since placing your home next to a large temperature differential is difficult...
Well, that's wrong. Every house sits on top of a significant temperature differential which is why geothermal systems work. In large parts of the continental US the ground deep beneath the house maintains a consistent temperature year round. This can be used as a thermal sink in the summer, and a source of heat in the winter.
a typical home of 2500 square feet, with a heating load of 60,000 BTU and a cooling load of 60,000 BTU will cost between $20,000 to $25,000 to install.
There can still be obstacles though. Quite a few houses here lack a distribution system for the radiators. Those radiators are directly connected to the electricity system. I.e. the house lacks a water-based heat circulation system (or similar). One could retrofit such a system, but then it’s about double the cost compared to only installing the geothermal pump. The background to this situation is partly that in the 70s, the government required houses to be built this way. Electricity was cheap back then, we had lots of nuclear and water-power and wanted to get away from oil.
Another thing to keep in mind that even a geothermal system requires some electricity to run – and they are not terribly effective when the weather is very cold outside.
It can be, assuming you are in the right location in the world. The problem is cost efficiency: you are talking about tens of thousands of dollars for a system that will only pay for itself in a decade (often times; in some situations this is the perfect answer). Geothermal is no silver bullet unfortunately. There is physical efficiency, and there is economic efficiency.
What does the geothermal story look like? I expect it's expensive to first set up, but after that, maybe it's cost-effective and reliable? Asking because I genuinely don't know, but haven't seen it mentioned in this subthread.
I'm kind of amazed that natural temperature management such as geothermal cooling isn't more of a thing. If you were to design a house with the sleeping spaces below ground, wouldn't you save a lot on cooling and heating costs?
Given the cost, it seems like there would be a big opportunity to install geothermal to bring that cost down. The payback would be quick with electricity costs like that.
Only a few feet deep? Maybe in select areas, but you generally have to go a lot deeper than that. It's been my understanding that the steep cost of geothermal involves the drilling. As much as $80K just to install a decent system, from what I've heard.
Geothermal makes so much sense conceptually. It seems ridiculous to run natural gas pipelines everywhere when there is a limitless supply of heat under every house provided one drills down far enough. Hopefully the process can be simplified and costs can be reduced significantly.
Please refrain from unnecessary, unsubstantiated insults. Rgbrenner's point that geothermal is costly for the same reasons that oil is costly - that is, it takes work to transport the energy in usable form - is valid. You're right that geothermal has a humongously deep supply curve, but that doesn't mean its price will be zero.
I recently learned that there are consumer grade heat pumps that can use geothermal by trenching a backyard or drilling some really deep wells. It didn't seem like the actual heat pumps were stupid expensive but of course the installation I have no idea how much something like that would cost. The install page I was reading said the trenches needed to be 6 feet deep and unknown how wide
Deep holes are expensive. Oil drilling, the cheapest kind of drilling since it's very common and in soft rock, costs $100-$200 per vertical foot.* A 2 km hole would cost $650,000 - $1.3M. It would not be economical to do this for one house. Then there are operating costs: operating a power plant on the surface is very likely to be cheaper than operating one underground, and temperature difference is bigger. All in all, a traditional geothermal plant (utility scale, at the surface) looks like that for good reasons.
My parents installed Geothermal a few years ago, which was expensive, like 30k I think, and it's helped, but not a ton as the line is still going under a frozen river in the winter, so the prices I quoted above are after geothermal. I think I saw a comment thread a few months back about how a lot of people got taken by the promises of geothermal and how they don't really do much for people in cold areas. It's great in the summer mind you. My buddy who works for Hydro One said a lot of folks end up paying the same or more after the install of geothermal because of how cold it is, which is really unfortunate. I looked at a big, nicer house in Nova Scotia that had dual geothermal and I was just drooling until I got my hands on the heating bills and was so confused why it was still so expensive.
They don't have wood burning and they are too old to be able to handle it anyway, you'd die from all the wood you'd have to cut and move and deal with. They said oil wasn't viable, and I don't think their house is setup for it anyway. They are worried about snow removal where they live as it's just too much for them now and it's so easy to get stranded for days, even though the city does eventually plow that road.
Where they live it's regularly -30 to -40c in the winter. They were snowbirds until Covid hit.
Yes, I did a lot of research into geothermal when I needed to replace a unit a few years back and there is no way I would have been able to recover the installation costs - even if I lived in the Northern most reaches of Canada instead of the mid Atlantic. Also it's very hard to find contractors skilled in installing the pipe correctly and far too many people had problems where they had to dig up portions of the loops for repairs.
If I ever have the chance I will have radiant floor heating. Once you experience it you won't ever want any other kind of heat. The colder it is outside, the better it feels - it's the ultimate luxury IMNSHO.
The gotchas are the energy used to run the circulator for the ground loop, and the fact that over the course of a heating or cooling season the ground temperature lowers or raises, respectively, by enough that the COP isn't even much greater than an air-source system (but this would definitely vary by climate).
Coupled with the much higher installation cost, it's a bit hard to make a system pencil out for a building the size of a single-family house.
A geothermal system for your house involves "transporting energy to your home" but the distances involved are so minimal that once installed it's next to nothing.
> Since placing your home next to a large temperature differential is difficult...
Well, that's wrong. Every house sits on top of a significant temperature differential which is why geothermal systems work. In large parts of the continental US the ground deep beneath the house maintains a consistent temperature year round. This can be used as a thermal sink in the summer, and a source of heat in the winter.
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