Frequently asked Questions and answers

Finstertal reservoir


What happens with the animals in the Längental valley?

The impact on the wildlife in the valley is limited to the areas under construction. Even small animals like newts, frogs etc. are collected before construction starts and are relocated away from the construction site. Suitable habitats like biotopes have been set up since preliminary work started in autumn 2019. In addition, protective fencing is installed and anthills are resettled.

What kind of compensatory action is taken?

Many different compensatory measures are taken to minimise the different effects on the environment.
Hydrological measures to improve habitats for fish and other organisms are carried out in and around the watercourses. As an example, the River Inn is widenend in several places between Stams and Rietz to promote a natural dynamic development. In several locations, the estuaries of tributaries are redesigned to allow fish to again migrate from the River Inn to the tributaries. In Langkampfen, an area of 3 hectares is restored to its natural condition to develop and widen the Inn floodplains. Many other hydro-ecological improvements and renaturalisation projects are planned not only for the main river of the  Tyrol but also for the Ötztaler Ache and the Stubaital and Sulztal streams.
To compensate for all interventions in nature in the best possible way, new biotopes for amphibians are created, wetland habitats are restored to nature, and valuable soils and plants are preserved. Comprehensive improvements to alpine pastures and forests are also intended to compensate for interventions in agricultural land.

When is the power station ready, and when will it start producing electricity?

Main construction work is scheduled to start in the spring of 2021. If everything goes according to plan, the power station will be operative and produce electricity in summer 2026. Completion of the entire installation is planned for the end of 2026.


How much energy can be produced after expansion?

Ever since the Sellrain-Silz group of power stations first went operative in 1981, the Kühtai and Silz  stations with the two reservoirs in Finstertal and Längental have been generating an annual 531 mio kilowatt hours (kWh) of clean and zero-carbon electricity from natural inflows. After expansion, an additional 216 mio kWh of electricity can be generated per year, all of it from natural inflows.

Is it possible to store the energy generated when demand is low?

Reservoirs are the most efficient way of storing surplus electricity produced from renewable sources. In pump operation, the Kühtai 2 powerhouse as part of the expansion project can pump up water from the lower Kühtai reservoir to the higher Finstertal reservoir and can later use the water in turbine operation to produce electricity on demand. This way, energy from the  high-production summer months can be "shifted" to the high-demand winter months.

Is this whitewashing electricity from non-renewable sources?

No, because the Kühtai 2 pumped storage station will only use certified electricity from renewable sources for pump operation, thus enabling us to store energy from other renewable sources like solar and wind.
The legal requirements help answer this question: Power station operators are obliged to provide proof of origin of the electricity used in pumped storage power stations. Compliance with this obligation is monitored by E-Control Austria, the authority that is also in charge of verifying the origin of the electricity used.
Pump operation at the existing Kühtai pumped storage station has verifiably relied on 100% renewable sources for years, and the new pumped storage station Kühtai 2 is also designed to utilise only electricity proven to originate from renewable sources.


Is the water polluted after electricity generation?

No! After driving the turbines in the power station, the water is returned to the stream just as clean as  before, without changes to its quality.

Is hydropower a clean/renewable source of energy?

About two thirds of the Earth's surface is covered with water. Water flows down the valleys in streams and rivers until it finally reaches the oceans, condensates through the power of the sun, ascends and descends again from the skies as precipitation in the form of rain or snow. This cycle is endless and is  therefore an inexhaustible source of renewable energy that humans have been using for their purposes for thousands of years. Hydropower does not cause pollution or leave residues, and TIWAG uses the water only to an ecologically acceptable extent.

First-hand experience

Can I visit the construction site?

Covid-19 currently makes it impossible to conduct site visits.

As soon as the situation changes for the better, our visitor centre in Silz will re-open to give you an insight into the construction progress. For safety reasons, visits to the construction site are limited and are subject to prior registration. We are planning to hold an Open Day at the site once a year.

Where can I find out more about TIWAG?

For more information about TIWAG, please call 0800 / 818 819, or visit us on the internet at www.tiwag.at