Quote:
Originally Posted by 240glt
^ well there’s no such thing as geothermal electricity perse. To make electricity out of geothermal energy you need very high temperatures from the ground capable of making steam to power a turbine. That’s doable in some places but not everywhere
Heat pumps work great in places like Vancouver where the climate is mild, down there you don’t need a ground source, just air to air. So down there, coupled with the province’s hydro electricity capacity they could easily transition away from natural gas. In places like Alberta you need to get heat from somewhere ie: shallow geothermal
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The way that conversations go, I would be fooled into thinking that there is some vast source of geothermal electricity out there just waiting to be tapped.
Quote:
Originally Posted by 240glt
Actually it's something of a hybrid it looks like. It's effectively using the ground as a heat sink to store thermal energy which it extracts to transfer heat through the condenser of the heat pump, used to effectively heat buildings when there is demand. What I'd be curious about is how much you can raise the ground temperature and how long that heat will remain. The last thermal storage project I worked on was a large storage tank buried under a building at the Edmonton airport which was designed to be cooled overnight when capacity was low and drawn out during the day when demand was high. It worked okay.. not great but okay.
The power costs you refer to are simply a factor of the size of compressor, condenser and associated specialties required for a heat pump to work in Alberta. I know they work here, our neighour has a shallow geothermal system with piping buried down underneath his slab on grade garage and a heat pump for the house. I believe he supplements heating with electric.
As I said heat pumps have their greatest potential in places like Vancouver where the climate is mild and heat from outside air can simply be transferred inside. An air-to-air heat pump. Once you get into cold climates you need to provide heat to the evaporator (Which is what the heat sink is in a shallow geothermal application) so a lot of condo buildings that use heat pumps will supplement the heat required for them to work by piping hot water from a heating boiler to the evaporators on the fan coils.
EDIT: I found some interesting information about the thermal storage system at that site. It looks like it took some time for the temperatures to get to a point where the system was effective (I actually think I remember that from the news when it first started) but over a number of years the system has reach equilibrium and is now working effectively
https://www.dlsc.ca/borehole.htm |
Very interesting - thanks!
I'm fairly skeptical that 'community' type heating sources like that one will ever provide a meaningful contribution in Alberta. We just don't have the socialisty attitude neccesary that any builders would have to possess to implement it in new communities. And retrofitting old communities I guess would be near impossible.
Is there much information on the economics of this?
Also - how does the glycol get to 80C? The sun can't possibly heat it up that much, can it?