More power for Austria’s largest “green battery”

The Malta-Reißeck hydropower plant group in Carinthia can store electricity generated by hundreds of wind turbines.

Following extensive modernisation and expansion, the pumped storage power plants around the Kölnbrein Dam have a turbine capacity of more than 1,500 megawatts, allowing them to feed the output of six Danube power plants into the grid at the push of a button.

In the Mölltal Valley in Upper Carinthia, the completion of extensive modernisation and expansion projects in Austria’s most powerful power plant group was celebrated today together with Governor Peter Kaiser and Deputy Governor Martin Gruber. Over the past five years, more than EUR 200 million has been invested in modernising the existing power plants Malta Hauptstufe and Malta Oberstufe, and also in constructing the Reißeck II+ pumped storage facility and the new Kolbnitz pumping station. The Malta-Reißeck plant group now has a turbine capacity of more than 1,500 megawatts, allowing it to feed the output of the six largest Danube power plants into the grid at the push of a button as required.

At the scene of the future of energy

With the modernisation and expansion of the Malta-Reißeck power plant group, VERBUND is already meeting one of the key requirements for a climate-neutral energy system. “When we talk about transforming our energy system, hydropower with its powerful pumped storage systems is crucial, because these power plants can compensate for the fluctuating electricity generation from wind and sun depending on the weather,” said Michael Strugl, Chairman of the Executive Board of VERBUND. “The pumped storage systems are therefore green batteries, and we are operating the largest of these batteries here with the Malta-Reißeck power plant group,” the VERBUND CEO said.

Governor Peter Kaiser was impressed by the modernised power plant group: “This completion is a milestone on the way towards a sustainable future of energy in Carinthia.” For projects like this one, it is essential that innovation, environmental responsibility and regional value creation go hand in hand, he said. “I thank everyone involved in planning, implementation and construction. Together, we have succeeded in making an important contribution to Austria’s security of supply and sending out a strong signal for the economic development of our state, because a secure, sustainable electricity supply also helps to preserve existing jobs and create new ones in Carinthia,” said Governor Kaiser. 

 Key role in Austria’s security of supply

“Austria is a hydropower country, with hydropower plants generating around 60 per cent of its electricity. At VERBUND, this percentage is even larger. Last year, more than 90 per cent of our generation came from our hydropower plants,” emphasized COO Achim Kaspar, who is responsible for hydropower on the VERBUND Executive Board. “Thanks to its large storage potential and particular flexibility, the Malta-Reißeck power plant group plays a key role in the security of electricity supply in Austria. For stable grid operation, generation and consumption must constantly match. Thanks to the highly efficient pump turbines, this balance is ensured here at all times.”

“With the modernisation and expansion of the Malta-Reißeck power plant group, a project has been completed that serves as an example of the path we are following in Carinthia: it combines innovation with regional responsibility. Projects like these make an important contribution to the security of supply and the independence of our state, and are vital for the development of regions and our location,” said Deputy Governor Martin Gruber.

Important stimulus for the local economy

“Our investment of more than EUR 200 million in modernising and expanding the installations in the Malta-Reißeck plant group is an important stimulus for the economy in Carinthia and Austria,” said Michael Amerer, Managing Director of VERBUND Hydropower. “We are currently implementing 14 modernisation and new construction projects with an investment volume of more than EUR 1.4 billion, mostly in Austria. Research shows that investments in energy infrastructure are an economic driver and have high regional and national added value, accounting for almost 90% of this project in Austria and a good 25% in Carinthia. In addition, significant follow-on investments are generated.” 

In the Malta-Reißeck power plant group, VERBUND has implemented several projects simultaneously in the past five years. The existing power plants Malta Hauptstufe and Malta Oberstufe have undergone major upgrades, boosting turbine capacity by around 40 MW and increasing pumping capacity by around 155 MW and generation by around 20 GWh. Two new flexibility boosters – the 45 MW Reißeck II+ pumped storage and the Kolbnitz pumping station with a 60 MW pumping capacity – have also been built. “In all of our measures, we have succeeded in adjusting our installations to meet future flexibility requirements as effectively as possible by using innovative techniques. For example, the use of variable-speed generator sets on this scale represents the most flexible pump turbine in the world – and it was made in Austria,” said Karl Heinz Gruber, Managing Director of VERBUND Hydropower. “We have increased the pumping capacity by 260 MW and the turbine capacity by 85 MW, and now have a total turbining capacity of around 1,540 megawatts and a pumping capacity of around 1,100 megawatts here in the Malta-Reißeck power plant group. Combined with the large storage facilities, we can temporarily store excess electricity from several hundred wind turbines.”

The power plant group started 70 years ago with a world record

The foundation for what is now Austria’s most powerful hydropower plant group was laid in the 1950s with the construction of the Reißeck power plant. The storage power plant was financed through the Marshall Plan and via the first loan granted by the World Bank to the Republic of Austria. 

With its high-altitude storage facilities on the Reißeck lake plateau, the Reißeck power plant held the world record for the hydropower plant with the largest drop height for more than three decades. The height difference between the reservoir and the powerhouse is 1,770 metres.

In the 1970s, the Malta power plants were built, as was the 200-metre-high Kölnbrein Dam – Austria’s tallest dam to this day. At 730 MW, the output of the Malta-Hauptstufe power plant was the same as that of the Zwentendorf nuclear power plant, which was then under construction. As part of the modernisation, the two large pumps and the four turbines were renewed in Malta-Hauptstufe power plant between 2019 and 2024. In Malta-Oberstufe, the two generator sets were completely rebuilt.

With the commissioning of the Reißeck II pumped storage power plant, which was completely built inside the mountain, the Malta and Reißeck power plant systems were hydraulically connected, creating one of the largest storage power plant groups in Europe. In addition to the Reißeck II power plant, work began in autumn 2021 on building the Reißeck II+ pumped storage power plant on the Reißeck lake plateau at an altitude of 2,400 metres. It is being officially commissioned today.

After completing these measures, the Malta-Reißeck power plant group now has a total of 11 power plants and one pumping station, and is the most powerful power plant group in Austria with a turbine capacity of 1,545 megawatts and a pumping capacity of 1,095 megawatts.