TU Graz scientists are working on transforming drainage water from the Brenner Base Tunnel (BBT) into a carbon neutral energy source.
“We are investigating whether and how the drainage water from the Brenner Base Tunnel can be used for climate-friendly heating and cooling of houses or even entire city districts in Innsbruck,” notes Graz’s Institute for Rock Mechanics and Tunneling director Thomas Marcher.
Once completed, the Brenner Base Tunnel should be able relieve the traffic between Italy and Austria in about ten years.
The scientists contend that adding a geothermal twist to it could take its eco-friendly quotient even further.
The sustainable concept – using heat in the diverted tunnel water to supply energy for industrial and household purposes – is being backed by the Brenner Basistunnel Gesellschaft (BBT SE) and Austrian electric utility company Innsbrucker Kommunalbetriebe.
Marcher’s team will use simulation models for the Brenner Base Tunnel to make an initial estimate of the infrastructural measures that are needed to achieve the highest energy yield.
“We are testing possibilities of whether and how we can raise the temperature of the drainage water to a higher level,” notes project coordinator Thomas Geisler.
“A conceivable variant are so-called absorber techniques (energy anchors or energy soles, note), which are installed on the inner wall of the tunnel and absorb the mountain heat.”
“In addition, we want to clarify how a sensible economic distribution of the water can take place in the households and how the heat pumps and heat exchangers have to be planned or adapted. “
The scientists are hoping to benefit from the unique selling points of the 64-kilometer-longest railway tunnel in the world.
Due to its length and its incline towards Innsbruck, the tunnel water in the Brenner Base Tunnel automatically flows towards the city without additional pumping.
In addition, there is an exploratory tunnel under the main tunnels, which is almost completed and through which the drainage water from the main tunnel will in future also be diverted.
Concepts for generating energy can thus be developed at lower costs without hindering rail operations.
Another important aspect of this research is transferability of the concept to other, already existing tunnels.
Marcher’s group will investigate which technologies can be used to supplement current tunnel construction projects and to retrofit already active tunnel systems in order to fully exploit their energetic potential.
Image and content: BBT SE/Graz University of Technology