The Berlin one also had some promising news today: https://www.adlershof.de/en/news/successful-tests-on-underground-heat-storage-in-berlin-adlershof https://www

The Berlin one also had some promising news today: https://www.adlershof.de/en/news/successful-tests-on-underground-heat-storage-in-berlin-adlershof https://www.adlershof.de/en/news/successful-tests-on-undergr... We have to see if and when any of them goes into production, but the technology seems very interesting