Seems similar to highview power. My current favourite is Fourth Power. But I used to like a bunch of other systems over the years. It's hard to tell which ones will make it.

Thx! Yes -Highview is compressed air; Synchrostor system has a novel high temperature heat pump that pumps gas and heats it and transfers to a low cost storage material. Similar to Fourth Power but lower temperatures and poss. a bit simpler! But yes there’s quite a few people out there doing this!