In Scandinavia this is routinely done via boring very deep wells, like 300m, https://hvac.okstate.edu/sites/default/files/pubs/papers/2016/Gehlin_Spitler_Hellst

In Scandinavia this is routinely done via boring very deep wells, like 300m, https://hvac.okstate.edu/sites/default/files/pubs/papers/2016/Gehlin_Spitler_Hellstr%C3%B6m_2016_Deep_BH.pdf https://hvac.okstate.edu/sites/default/files/pubs/papers/201... This may not be suitable for skyscrapers, but it works for 4-5 store apartment blocks.