zlacker

>>PaulHo+(OP)
Perhaps I am missing something; this product already exists as the Sunamp Thermino.

https://sunamp.com/en-gb/hot-water-solutions-thermino-range/

>>chicke+jq1
It also exists, as described in the headline, as a tank of heated water.

The phase change stuff has positives like taking up less physical space but it's also a much less mature tech than storing hot water.

>>ZeroGr+ev1
Indeed.

In the UK there was a unfortunate trend of ripping out these energy storage devices and replacing hot water tanks with on demand electric hot water heating ( only heat the water you need ). And new builds often have no tanks ( as it saves space in the new tiny homes ).

Very short sighted in my view - a very simple way to store energy and everyone uses hot water directly.

>>DrScie+SF1
They don't work well with heat pumps. Heat pumps lose efficiency as the differential increases, so if you try to store heat in a tank, you quickly drop capacity and efficiency.

Versus resistance, which is exactly as efficient at 0°C and 1000°C, and why those storage heaters used to make sense.

(And storage is directly proportional to temperature differential above interior ambient)

>>coryrc+OY3
Isn't it better to heat the water up to a point (let's say 40 or 50 degrees) and to heat it the rest of the way with resistance heating?

>Versus resistance, which is exactly as efficient at 0°C and 1000°C

It isn't. The difference is smaller than for a heatpump tho obviously.

>>modo_m+mp5
1. No, absolutely not. Why would you settle for COP=1 when you can have COP>1?

2. The electrical to heat conversion efficiency is indeed 100% regardless of the temperature of the resistor. And if you're putting out 1000W, then all input losses are also identical. If you put a 1000W light bulb in the middle of your room, or 2 of them but run both at 500W, you'll get EXACTLY the same heat output in your room, but the single bulb is much hotter.

>>coryrc+SD8
1. Are there not scenarios where it drops below 1? The stats for them always seem optimistic scenarios given what i hear from people during winter cold spell in houses that aren't absolutely perfectly insulated. If your water term needs to remain above 70C and it's starts freezing hard outside during winter when that COP starts to matter the most for example.