COP of 5

[Koen1]

I think it depends on what you view as the system.

Take your example of the heat pump; it needs a heat source to operate. If we include the heat source, the system of heat source + heat pump never has a COP > 1.

I guess that's how they viewed the geothermal thing too: the machinery to convert geothermal energy into usable (electric) energy uses 1/6th of the total produced energy to do its job. That leaves 5/6th output. The ouput is then 5 times the input, as long as we ignore the fact that 100% of all that energy comes from the earths heat. If we only look at the machinery we build, and ignore the heat source, then the machinery may have a COP of 5. But if we include the heat source, then of course not.

Lol then again, I could be talking bull as well. 

[z_p_e]

Geothermal heating and heat pumps are OPEN SYSTEMS, therefore COP's >1 are possible.

That's how you can have COP=5. As Dave said, efficiency means nothing in the end. All you're interested in is how much heat (or energy) do I get out for what I put in.

If the end-result output exceeds your input, you have  a COP>1.

[Koen1]

Yes, isn't that what I said? Or did you not read the post?

Of course, technically even closed systems are "open" in a way, since they lose energy in the form of heat due to resistance or friction...
If the system was truly closed, the heat could not escape fro mthe system, and entropy would be violated...

[z_p_e]

I read your post, and to be honest I'm not sure what you said.

[Paul-R]

If we fly in ever more decreasing circles, we may end up flying up our own back passages.

Technically, nothing is OU. The energy comes from the ZPE, vacuum state or whatever.
Geothermal energy, for the few for whom it is available, is good news. A free lunch, once
the set up and running costs are paid for.