Switzerland just activated an innovative heat recovery system extracting thermal energy from the rock surrounding its major Alpine road tunnels to warm 80.000 mountain village homes all winter.

 

Switzerland just activated an innovative heat recovery system extracting thermal energy from the rock surrounding its major Alpine road tunnels — capturing heat that maintains tunnel air temperatures year-round and redistributing it through heat pump networks to 80,000 mountain homes in Valais and Uri cantons.

The Swiss Alpine Tunnel Heat Recovery system installs heat exchanger panels inside the walls of 14 major Alpine tunnels including the Gotthard, Simplon, and Lotschberg tunnels. Rock surrounding the tunnels maintains 10 to 15 degrees Celsius year-round regardless of surface temperatures. Heat pumps boost extracted temperatures from 12 degrees to 65 degrees Celsius suitable for residential radiator heating systems.

Switzerland has 3,000 kilometers of road and rail tunnels bored through Alpine granite — each constantly radiating geothermal warmth that previously escaped into cold mountain air. The program captures this free thermal energy from existing infrastructure with zero additional environmental footprint.

Source: Swiss Federal Roads Office ASTRA, Swiss Federal Office of Energy, Valais Canton Energy Authority, 2025

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