| > you're confused about the thermodynamics of the situation. I assure you I am not, it is actually you who still seem confused about where the energy is coming from. > they're not giving you more energy than what you put into it. When you burn gas in a furnace, all of the energy that raises the temperature of the house comes from the gas. When you run a heat pump you have two sources of energy: 1. Electricity running the thing. 2. Heat from the outside that you're moving inside. #2 is where most of the energy that actually heats up the house comes from. The electricity is used to move it from outside the house to inside. > Burning that gas in a turbine & then transferring that energy through a bunch of transformers to get to the heat pump can't give you more heat than what went into combusting the gas in the first place. It actually can. A combined cycle plant can be ~60% efficient (chemical energy -> electricity). Say another 70% for getting it from the plant to your heat pump, then a COP 3 (or "efficiency" of 300%) gives you 0.6x0.7x3 or 1.26. So for every J of natural gas you burn in that plant, you'll heat your house with 1.26 J (compared to at best 1 J, realistically 0.9 J, for a gas furnace). If you instead look at a ground source heat pump, you can get a COP of ~7 [0]. You're now putting ~3 J of heat into your house of each J of natural gas. [0]: https://en.wikipedia.org/wiki/Heat_pump#Performance |
Heat pumps are basically taking advantage of solar + geothermal radiation that ends up in the ground & air but once you account for the solar + geo radiation then it becomes obvious that all a heat pump is doing is accelerating the production of entropy. You're either normalizing the delta between inside & outside or increasing it but in both cases the overall entropy of the system goes up. Whereas your accounting seems to suggest you somehow get more energy than what was available which is obviously unphysical.