3 ms·

Specifically, a heat pump water heater.

• xxpor 4y ago
  That usually is true if your electricity is generated by natural gas too and you're comparing it against a gas HWH Rough math is NG -> Electricty is 50% efficient thermally. A heat pump can have a COP of 4.2. 100 * .5 * 4.2 = 210% efficient, thermally A hot water heater powered directly by gas is ~100% efficient thermally.
  • kkfx 4y ago
    Personally I do not care about efficiency: I can't sell energy I produce so the point is just heating the water and the load profile of a classic resistance and the load needs of my houses match normally to heat without the heat-pump (witch have a far limited life respect of a classic resistence)... I use the heat pump mode only when there is little solar for few days where there is not enough overall energy production, otherwise being able to produce 120-130% of the overall consumption (of course ONLY when the Sun shine, so NOT independent as some sell just playing with absolute numbers) why care about efficiency? I can't use the extra energy anyway...
• ars 4y ago
  So I looked into them because of your comment, and they have a very big drawback of taking a very long time to heat the water. That wouldn't work for me, our water usage tends to be very "peaky" - my system can heat the water almost as fast as you can use it in a shower. Maybe with a very complicated system with an extra large storage tank, and perhaps integrated with the home heat (so a single heat pump). I feel like the tech isn't quite ready yet, and I don't like being a pioneer. It seems like a no brainier if you heat with electricity, but not quite ready yet for those who heat with natural gas. Right now it seems better suited for southern climates.