Technology aside, rollout of such technology in Europe would be sabotated by russkies in the same way shale gas/oil was (sadly successfully). This must be accounted and planned for. Fossil wholesaler of the Siberia does not want you to be gass/oil independant.
Geothermal's path to relevance: cheap drilling
71–77 of 77 posts
Re: Geothermal's path to relevance: cheap drilling
#72I live in Ithaca, and Cornell is about to start drilling a test borehole in the coming year. Once the borehole is completed and some tests made, they'll drill a pair of production boreholes about 10,000ft deep.
The goal is to pump water down one, and extract it from the other borehole and then use a heat exchanger to pull the anticipated 160F to 180F temperature to provide heat to the entirety of the campus.
It's similar to the University's Lake Source Cooling system, which they use the naturally cold water temperature of the local Cayuga lake. At the 250' depth they draw the water in, it's a constant 39F year-round. The cooling system is used to provide chilled water to all the buildings, and a few thousand homes, removing the need for standard air conditioners.
The Lake Source Cooling system has saved the university 20 million Kwh a year, an 85% reduction in power usage, since it was made in 2000. It's hoped that the Earth Source Heat project will have the same kind of impact on the energy necessary for heating.
There are a lot of unknowns. Nobody has drilled a borehole so deep in this area before because there hasn't been a reason to do it before.
[1] https://earthsourceheat.cornell.edu [2] https://fcs.cornell.edu/departments/energy-sustainability/ut... [3] https://fcs.cornell.edu/departments/energy-sustainability/ut...
Re: Geothermal's path to relevance: cheap drilling
#73Earlier quoted context omitted.
It’s often less about the heat flow than simply the amount of heat contained in that volume of rock. For your example: A 1/2 acre home is 2023 m2, 1kg of rock is ~2000j/degrees Celsius, 1 cubic meter of rock is ~2500 kg, down 1k = ~2000 j * 2500 * 2023 * 1000 / 60 / 60 / 1000 ~= 2,800,000 kWh per degC. If you’re talking 1kw of heat on average from that rock you only drop 1 degree after 300 years. Of course 1km is a f…
This is totally irrelevant to anything in the article, except in the sense that both pertain to thermal energy and the earth. They have nothing else in common. You can't run a factory, a computer, or a car off a ground-source heat pump, because heat pumps consume energy; they don't produce it.
Most of that post had nothing to do with heat pumps, however digging 1km down for a single family home is generally a poor method of extracting energy from the earth as it can be as little as 6C and is only 25C on average above ambient temperature.
Much higher ground temperatures are of course useful to create electricity, but such systems are best centralized not used for single family homes. Also, as a centralized system it’s volume is arbitrary. In the north that 6-25C can still make heat pumps vastly more efficient, but you’re extracting energy and cooling that down over time. Which is why it is relevant to the discussion.
Re: Geothermal's path to relevance: cheap drilling
#74Earlier quoted context omitted.
You can go vertical instead of horizontal
We have two 350' wells for loops at our house in Maryland. Tripled square footage in the new house and energy costs stayed the same. Moved from natural gas for heat, but still have it fir backup (which in a decade has never been needed).
You must live in a rural county. There are strict regulations on well depths and aquifers utilized in my area of MD. Two aquifers, one being ~50ft and the other being ~300ft are present, and we have to connect to the deeper of the 2. My neighbor 250ft away has an older house connected to the shallower aquifer.
That said, my residential options for energy are rich. I have the Chesapeake Bay 80ft from my current heat pump. So I could theoretically implement a plethora of heat exchange mechanisms taking advantage of that. Wind power is feasible except for the footprint. Yesterdays 35kt gust may have been a bit much tho. Have waves that could power things also. And mostly unobstructed roof which could host solar. Tidal range is not very large, and current is greatly reduced near shore.
Re: Geothermal's path to relevance: cheap drilling
#75Earlier quoted context omitted.
This is totally irrelevant to anything in the article, except in the sense that both pertain to thermal energy and the earth. They have nothing else in common. You can't run a factory, a computer, or a car off a ground-source heat pump, because heat pumps consume energy; they don't produce it.
Most of that post had nothing to do with heat pumps, however digging 1km down for a single family home is generally a poor method of extracting energy from the earth as it can be as little as 6C and is only 25C on average above ambient temperature. Much higher ground temperatures are of course useful to create electricity, but such systems are best centralized not used for single family homes. Also, as a centralized…
I agree with most of that.
Re: Geothermal's path to relevance: cheap drilling
#76Earlier quoted context omitted.
Drilling cost is usually estimated for drilling in sedimentary rock with assumptions about how casing is run ;) It is possible that drilling 30,000' of granite has conditions that make the estimation model irrelevant. 5 km isn't really deep enough, anyway. My next post will cover the thermo. It is pretty dang hard to get down to anything approaching $50/MWh. Definitely need more than cheap drilling.
It is important that we discuss cost, but I think the urgency of our need for mass generating non-intermitent power should override costs. As an example Solar energy as it exists now would have been ridiculed in the late 80s as something that would never be cost effective. It was the massive subsidies/tax rebate schemes in Germany and later on in other EU countries that open the window for manufacturers to produce at…
Germany has a 220 euro/kWh feed in tariff subsidy for geothermal.
Re: Geothermal's path to relevance: cheap drilling
#77Earlier quoted context omitted.
Only if they have access to another source of energy to power the heat pump and the other machinery that doesn't run on low-grade heat.
Sure, factories run on many inputs, you cany do much with just electricity either :)
Energy has a special place: every factory uses it, and you can do a lot with just energy, minerals, labor, and space.