Tunnel heat
Overview

A considerable quantity of warm water very often flows off to the portals in tunnels. Because of its temperature this water cannot be derived without previous cooling into the environment. This energy potential (drained warm water + warmed up air) can be used at the tunnel portals for different applications.

 

A local energy source, which is valid to seize it

Südportal des Simplon-Tunnels. © Photo-Service CFFTunnels and lugs drain the rock, which they cross. The water is led outside, cooled down over channels and in most cases supplied to a running water (river). According to the rock coverage of the tunnel the water temperature can raise up from 20 to 40°C or even more. With a sufficient productivity this geothermal energy potential can be used for heating purposes for consumers in the proximity of the tunnel portals. With more than 700 railway and road tunnel Switzerland possesses one of the highest densities of such buildings.

Recently six heating systems in Switzerland, which use the tunnel warmth, exist: Gotthard road tunnel, Furka, Mappo-Morettina, Hauenstein, Ricken and finally the Grosser St.Bernhard, in which not the drained water but the warm air of the tunnel is used.

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