For example, this project [1] in Finland will provide 200 MW of district heating and can store 90 GWh. Cost estimate was 109M EUR in 2021 [2].

[1]: https://www.vantaanenergia.fi/en/we/carbon-negativity-2030/h... [2]: https://tem.fi/paatos?decisionId=0900908f8077a0e8

Interesting. We'll see in 2026 when it's finished how much it actually costs and how well it actually works :)

Cool, so you would only need about 120 of those to compensate Germany's current wind and solar power in the gaps without wind and sun. That's just 1.3 billion Euros. That's better than the last time I checked out heat storage. Then it was 100MWh for roughly a football stadium sized area with subterranean sand.