| Ground source heat pumps, AKA what most people call 'geothermal', have their own inefficiencies. In the winter, when you're using it to heat, it collects heat underground and brings it up to be concentrated and released into your house, this concentration costs energy. Though in the grand scheme of heating your house, any heat generated inside your house isn't a loss. Due to the fact you have to have buried pipe which you pump liquids through, you'll lose some efficiency to head loss and gravity. Those loses happen outside your house too. Ground source heating is a lot more economical as it uses far less electricity than resistance heating for the same BTU output (because it's "stealing" heat from somewhere else), but it's not more efficient. But if you ask anyone who has to heat their house in the winter, electric heat is the most expensive. It may be efficient, but electricity isn't cheap. As for cooling, Ground Source Cooling would be more efficient than a conventional AC (as it's not compressing and then evaporating a refrigerant on a coil). The nice thing about cooling, its greatest demand typically coincides with the best time to collect solar energy. Solar is perfect for offsetting the a/c, they are a great combo in sunny warm climates. I hadn't ever thought about the double effect of solar panels on your roof protecting your house from heating up by absorbing the sun, and then using that power to cool your house further. That synergy makes me smile. |
Bottom line 1500w heater puts 1500w into the room 100% efficient, a 1500w heat pump will put 4500w or more into the room 300% efficient or more, they both use the same amount of electricity.