Tuxbach crossing project with Stillup small power plant

VERBUND and the utility company Stadtwerke Schwaz are planning optimised use of the Lower Tuxbach and the construction of a new small power plant in Zillertal. New, efficient technology is replacing old machines. The Tuxbach crossing project has been under construction since the beginning of 2017.

Groundbreaking ceremony for the Unterer Tuxbach project

"Groundbreaking ceremony for the Unterer Tuxbach power plant"
At the groundbreaking ceremony on the Unterer Tuxbach (from left): Heinz Nyvelt (plant group manager, VERBUND), Marco Fiegl (project leader, VERBUND), Karl Heinz Gruber (managing director, VERBUND Hydro Power GmbH), Simon Grubauer (mayor, Tux), Günther Rabensteiner (Executive Board member, VERBUND AG), Monika Wechselberger (mayor, Mayrhofen), Josef Geisler (vice governor, province of Tyrol), Andreas Kröll (mayor, Finkenberg), Hans Lintner (mayor, Schwaz), Helmut Mainusch (managing director, Stadtwerke Schwaz GmbH), Michael Amerer (managing director, VERBUND Hydro Power GmbH)

New, efficient technology is replacing old machines.


The Zillertal is surround by 3,000-metre peaks and its extraordinary topography makes it an important energy supplier for this region shaped by tourism. The reservoirs and the eight hydropower plants of the Zillertal plant group can supply 365,000 households with green energy.
The permit for the Bösdornau power plant (part of the Zillertal plant group) expires in 2019. An environmentally friendly and yet economical solution for using the Unterer Tuxbach has been developed and approved with Stadtwerken Schwaz (German only) and will be put into use when the permit expires. To this end, an underground connection between the Tuxbach and the Stillup reservoir will be made and a green electricity power plant with a power output of around 1.7 MW will be constructed at the end of the crossing, at the confluence with the reservoir. The Tuxbach crossing project in the Tyrol’s Zillertal valley has been under construction since the beginning of 2017.

In future, the water of the Unterer Tuxbach should drive the turbines in the Mayrhofen power plant. The power of the water should be put to the best-possible use in accordance with the state of the art by feeding it into the Stillup reservoir. In addition, the gradient between the Unterer Tuxbach and the Stillup reservoir will be used in a new small power plant to generate clean electricity from hydropower.

Project folder Unterer Tuxbach (German only)

Image from the Location

Owner VERBUND Hydro Power GmbH
Operator VERBUND Hydro Power GmbH
Type Run-of-river power plant
Country Austria
Region Tyrol
Output 02 MW
Annual output 74,000 MWh
Fish bypass

A central element of the Tuxbach crossing is an 8.6 kilometre-long tunnel connection between the lower Tuxbach and Stillupp reservoir. The total construction time for the project, which commenced at the beginning of 2017, is estimated at 3 years.

At the end of the crossing, at the confluence with the reservoir, a green electricity power plant with a power output of around 1.7 MW will be constructed. The unique combination of the new crossing and the connection with the existing power plant at Mayrhofen and the new Stillupp small power plant will facilitate the generation of around 45 GWh of hydroelectricity per year.

In the existing powerhouse at Bösdornau, only one machine set will now be operated with the water of the Zemmbach, in order to cover the power plants’ own needs and to ensure cold-start capability in the event of large-scale power failures. In this way, it remains possible to use these plants for step-by-step restoration of the power supply across the country following an outage. The residual use of the power plant at Bösdornau also ensures that the industrially historic and attractive power plant constructed between 1928 and 1930 remains part of the history of hydropower in the Tyrol and at VERBUND.

 
Hydro Consulting from VERBUND
Environmental protection at VERBUND

The existing Tuxbach power plant in the municipality of Finkenberg in Zillertal is to be abandoned. The removal of the Großdornau basin, which is part of the power plant, has been negotiated with the municipality and will create open areas for use as it sees fit. The pipelines that currently run above ground to the Bösdornau power plant will be laid underground in the Großdornau area.

The implementation of the project was examined for its ecological impact and the preservation of natural conditions, and appropriate measures were taken into account in the construction plan.

 
Responsible treatment of the environment

Summer 2017 at the Lower Tuxbach tunnel construction site

The central element of the Lower Tuxbach project, which is being implemented in the Zillertal Valley in collaboration with Stadtwerken Schwaz (German only), is an 8.6 km long connecting tunnel between the lower Tuxbach stream and the Stillup reservoir. Over the course of the last months, by means of blasting, the conditions were created for use of a tunnel boring machine. Its use was launched with a little ceremony in front of the tunnel portal, to express the hope of successful and especially of accident-free construction. The tunnel boring machine will first advance the tunnel starting from Karlsbach in the direction of Tuxbach. Then the machine will be withdrawn from the mountain and will create the connection between Karlsteg and the Stillup reservoir.