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
I think the advantage is that hot water loses heat over time, depending on how good the insulation is. However with phase change materials, the heat is trappped in the phase change and is stable until you release it.