Carved into the rock beneath a Swedish city, a huge man-made cave system dating back to the Cold War is being used to heat local housing. DW found out how it works.
Source
Carved into the rock beneath a Swedish city, a huge man-made cave system dating back to the Cold War is being used to heat local housing. DW found out how it works.
.. . . . . . . . . . . . . . . . . . . . . . . . . %%%. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ - - - - - - - - - - - - - - - - - - - - . . . . .