* . * . * .

Can caverns of piping hot water heat our cities?


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

.. . . . . . . . . . . . . . . . . . . . . . . . . %%%. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ - - - - - - - - - - - - - - - - - - - - . . . . .