What's the round trip efficiency of something like this, and what's the rate of loss to the environment? There's been a couple of these posted in the last few days and I have no feel for these numbers.
It's electricity powered thermal storage for municipal heating.
Which, in my opinion, is a smart idea. Why bother converting the heat back to electric to end up being used to generate heat in homes.
You could use this as a heat sink at the home attached to a high efficiency heat pump for 6:1 thermal efficiency.
We could do with municipal heating here in Tasmania
The important insight here is that per Carnot's law[1], the higher the storage temperature the higher the theoretical max efficiency for thermal storage. Stiesdal had an initial concept that stored at even higher temperatures (1000C) and used a standard power plant steam turbine for converting back to electricity. But these turn-key solutions are probably more realistic.
If you are interested in realistic renewable energy, do browse the Stiesdal pages: Henrik Stiesdal [2] was pretty much the inventor of the modern wind turbine (sold the upwind 3-blade design to Vestas, CTO at Siemens Wind Power): He seems to have a superb intuition for industrializing heavy machinery. I am keenly following his advances into electrolysis and floating offshore wind power.
[0]: https://www.stiesdal.com/storage/the-gridscale-technology-ex... [1]: https://en.wikipedia.org/wiki/Carnot_cycle#Carnot's_theorem [2]: https://en.wikipedia.org/wiki/Henrik_Stiesdal
It's not going to be as good as a heat pump, but they don't work very well in very cold climates, and storing electricity (or energy that you turn back into electricity) is expensive/lossy/difficult.
https://www.dailymail.co.uk/sciencetech/article-10982885/Wor...