Quote:
Originally Posted by redpoint5
Seems to me the problem of not enough heat extraction has a few possible solutions.
Increase the volume, especially the surface area of the "hot pocket"
Use the thermal conductivity of water to extract the heat
Drill near volcanically active areas to increase the temperature
I've always wondered why a heat pump couldn't be used to achieve the necessary temperature for steam generation? They're at least 300% efficient, so in theory one should be able to run a steam turbine from a heat pump and have a net gain in electricity, especially if you're already starting with pretty hot temperatures.
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Steam turbines operate at up to 720-F, and 1885-psi.
To commute employees to a distant mine, in 25% efficient cars, operate all the heavy diesel and electric-powered equipment to mine fuel, then transport the fuel 1,500-miles on a diesel-powered railroad train, to a fossil-fuel powered power plant, then burn it to make heat, to boil water, to make steam, for a turbo-generator, to make electricity, and transmit it over an electric grid, to run an electric motor, to operate a heat pump compressor, to reject heat, to make steam, for another steam turbine, to make electricity, to wheel onto the same grid, with conversion losses at every step in the process, has a high probability of wasting all of the 400% efficiency of the heat pump, and probably at such a loss as to be economically unfeasible. Otherwise, everyone would already be doing it.
You're fighting the Second Law of Thermodynamics at every step.