I honestly thought it would be bigger. Having said that, we (as in the municipality i work for) currently have 40-60 MWh sand batteries in production. The first, small and hot, one is currently charging to go into production when it gets colder. The bigger and colder battery is slated to start charging the next season.

“And you can store it for long periods, not just two hours or four hours like lithium-ion batteries, but potentially for days and maybe even weeks.”

I’m guessing here, but “for days and maybe even weeks” must be because the battery is above ground? With good insulation seasonal storage is very much in the cards.

A day care in another Swedish municipality use about 1/5 of the “normal” energy for heating thanks to a sand battery. As in 15-18 kwh/m2/year as opposed to 70 kwh/m2/year as is the current upper limit for new buildings in Sweden.

So far I’ve mostly changed how I do stuff, rather than what i do. Electric car instead of ICE, Bike and train for commuting, Solarpanels and 20kWh batteries for most of my summer time energy needs.

At work I have more possibility to make a difference, though. So far I’ve had batteries introduced (solar was already norm) as an accessory to “our” buildings, I’ve gotten 2 thermal batteries (sand) built and are currently investigating building mounted small scale wind power. Among other things.