There's a pretty significant upfront cost in getting them drilled, and many homes need the vertical drilling if they don't have sufficient yard space for a horizontal system. It gets harder if you have your own septic drain field too, as that will complete for yard space.
The cost difference is pretty massive- 3-10x for a vertical system. If you live in a city or a suburb with tiny lots, that's your only option though.
I paid about EUR 4500 for a 114 meter drill hole including installation of brine (ethanol in my case actually) and removal of spoils. My 8kW heat+water pump was about EUR 7000.
I can spec out a gas burner for about EUR 4000 and a central AC for EUR 5000, but I bet the efficiency of the ground source heater would quickly trump the cost of buying gas regularly.
Although if you needed a new septic field, I would think ground source thermal would be significantly deeper than a drain field which is only like a foot or so down so you could stack them.
Air source heat pumps are insanely more efficient and just plain better these days too. It used to be that if the air was below 40F you couldn't heat your house with a heat pump. Now, you can heat your house even when it's -10F
If you can tolerate the price, I am _confident_ that you will pretty much always have better results using the Earth as your thermal exhaust, because you don't have to dig very far to find a large region that's pretty much always at 50 F.
The price of things - heat pumps and alternatives - in different regions - even different regions within the US - varies by what people are prepared to pay not what they cost to produce.
The nordics have traditionally had cheap heat pumps whereas piped gas is only in the biggest cities and I’ve never seen bottled gas in the countryside. The competitor used to be cheap electricity and wood. Ground source heat pumps for rural install have been priced to compete with wood.
In the US the market could be shaped by regulation and taxation etc. It’s the choice of the US to have cheap fossil fuels and not embrace tech instead.
> Air source heat pumps are insanely more efficient
Citation needed?
Efficient how? I'm sure a heat pump designed for a narrow range of input temperatures AND working with water which can transport a lot more heat should easily be more efficient.
The cost difference is pretty massive- 3-10x for a vertical system. If you live in a city or a suburb with tiny lots, that's your only option though.
Nat gas and central AC are way cheaper.