Sustainable: voestalpine and hydropower 6 minutes spent reading

Sustainable: voestalpine and hydropower

Volkmar Held
As a freelance writer, Volkmar Held reports for voestalpine on topics that move people. The content of his stories ranges from archaeometallurgy to future technologies.

Hydropower is an established method of sustainably generating electricity. As the backbone of green power generation, one sixth of global electricity supplies are generated using hydropower. voestalpine is a strong supporter of hydropower.

Hydropower plants can be hidden in mountain valleys and underground caverns, or take the form of immense structures built on an impressive scale. Whatever their form, they are invaluable for sustainable power generation. And whether hidden away or out in the open, voestalpine supplies key components for all these sustainable electricity generators, whether run-of-the-river, storage, or pumped-storage power plants.

An important sixth

The power of water has been playing a decisive role in the development of technologies and cultures for millennia. Today, hydropower forms the backbone of low-emission electrical power generation, making it THE supporting factor behind the energy transition. It currently accounts for one sixth of all electricity generated worldwide. It seems rational to construct hydropower plants, especially as, to date, only 25% of global potential for hydropower is being exploited.

The benefits of hydropower

It is currently the most important sustainable source of electricity, because hydropower…

  • supplies almost half of electricity generated using renewables globally;
  • saves CO2 emissions: 1 GW of hydropower avoids 4.4 million tons of the CO2 emissions otherwise produced by generating electricity using coal and gas;
  • capacity is forecast to grow by around 230 GW globally by 2030. That is 1,300-times more than the output of the Ottensheim-Wilhering hydropower plant on the Danube.

In Austria, a country blessed with water, the focus lies on storage, pumped-storage, and run-of-the-river power plants. Here alone, 5,200 small hydropower plants, i.e., generating less than 10 MWh, produce electricity from smaller bodies of running water. voestalpine operates seven such hydropower plants.


The Böhlerwerk hydropower plant belonging to voestalpine Precision Strip GmbH

The Böhlerwerk hydropower plant belonging to voestalpine Precision Strip GmbH

voestalpine companies are supplying the global marketplace with various products and services to support the expansion of hydropower.

voestalpine for hydropower

Reliable materials are essential for safely and efficiently harnessing the immense power of water and converting it into electricity. voestalpine companies supply the energy industry with forged and cast components for hydropower plants, electrical steel strip for generators, heavy plate for pressure pipes, and special welding consumables.

When you think of hydropower, you think of water wheels. The principles of this archaic form of exploiting hydropower remain valid to this day—it is only the form which has changed as technology develops. Modern Kaplan or Pelton turbines turn the running power of the water into rotating movement which generators then convert into electrical energy.

"Whether Francis, Kaplan, Pelton or pump stator disks, the voestalpine Foundry Group supplies a wide range of cast steel products for today’s highly efficient hydropower plants. They include components of huge dimensions: some weigh more than 50 tons, with diameters of six meters and more."
Sales Manager, Markus Z.
Markus Z., Sales Manager, voestalpine Gießerei Linz

Markus Z., Sales Manager, voestalpine Foundry Group


The voestalpine Foundry Group supplies components including Francis and Kaplan blades, stator disks, adjustment cranks, and hubs which drive enormous turbines. The materials used combine extreme strength with toughness at low temperatures and are easily weldable in order to meet the requirements of hydropower plants. The voestalpine Foundry Group achieves the challenging geometries of the hydropower components using innovative technologies, explains Markus Z.: “We use methods such as 3D printing to create the sand molds used in casting, allowing us to manufacture the most complex of forms quickly and with great precision.”


Francis stator disk: a 3,000 kg cast part for hydropower

Francis stator disk: a 3,000 kg cast part for hydropower

Electrical steel strip for electricity generation

The basic principle of electricity generation is converting mechanical into electrical energy. This applies just as much to sustainable power generation as to conventional forms. That makes electrical steel strip a highly sought-after material for use in generators, with global demand increasing by five percent annually. It plays a key role in increasing the output of renewable energy systems, which is why generators are retrofitted with high efficiency electrical steel strip such as isovac® from voestalpine Stahl GmbH when hydropower plants are upgraded.


  • Hydropower from Ottensheim: voestalpine electrical steel strip to increase generator output

Ottensheim-29 is one of the current hydropower revitalization projects. The operator reports that since 2020, the output of the nine pairs of turbine generators at the Ottensheim-Wilhering run-of-the-river power plant on the Danube is being given a 45 MW boost. This will generate additional electricity for 16,000 households, with the aid of isovac® electrical steel strip from voestalpine.

"The French contractor wanted to know all about the material being used to upgrade the generators which are over 50 years old, and was convinced of its suitability. We are supplying 50 tons of electrical steel strip for each generator at the Ottensheim-Wilhering power plant until the project ends in 2029."
Jean-Luc F., Business Development for the Electrical Industry at voestalpine France SA

The reliable quality of voestalpine electrical steel strip guarantees for years to come that power plant operators always have material of a consistent grade for generating electricity. “We have enjoyed years of trusted cooperation with the generator manufacturers,” says Jean-Luc F.


Store energy and withstand pressure

One of the major challenges of the energy transition lies in storing sustainably generated electricity. Where to put the megawatts produced by PV systems and wind turbines generating peak levels of output on sunny days with constant wind? Pumped-storage power plants are one solution. The basic principle is to pump water uphill into reservoirs using the surplus electricity generated at midday, so that the energy is available at any time as required. The operators need durable materials to turn this idea into reality. The pipe connections between reservoir and generator must be able to withstand the pressure of water volumes which often rush downwards over a distance of several hundred meters. This is only possible with reliable steel grades.

  • With pressure to electricity: pressure pipes from voestalpine

voestalpine Grobblech GmbH is accustomed to high loads and extreme demands. The fine-grained steels made in Linz can provide both the necessary yield strength of 700 MPa and trusted reliability.

“Repairing or exchanging pressure pipes in the mountains or even underground is a hugely demanding task, which is why we supply manufacturers of pumped-storage power plants with high-strength, shatterproof heavy plate which is particularly suitable for welding,” confirms Head of Marketing, Christian F. “After all, such plants often have an operating lifespan of 80 years and more.”

Christian F., Head of Marketing, voestalpine Grobblech GmbH

Christian F., Head of Marketing, voestalpine Grobblech GmbH


9,000 tons of voestalpine high strength heavy plate are hard at work at the Kaunertal pumped-storage plant in Tyrol, Austria. voestalpine is supporting a key aspect of the energy transition with pressure pipes which have a diameter of up to 100 mm: storing sustainably generated energy. Storage power plants are also optimal for powering up power plant networks. They can provide electricity in as little as 30 seconds.

However, large investments and extensive changes to the natural landscape are needed to construct pumped-storage power plants. In view of the current lack of network capacity, the challenges of immediately using surplus PV electricity to drive pumps located in remote areas have not yet been satisfactorily solved. Despite this, experts calculate that the continued construction of pumped-storage power plants will result in output of over 50 TWh by 2030—a 50% increase over current levels.


Pressure pipes of huge dimensions provide hydropower underground (© Bilfinger Industrial Services)

Pressure pipes of huge dimensions provide hydropower underground (© Bilfinger Industrial Services)


voestalpine heavy plate used in the Kaunertal pumped-storage power plant (© Kremsmüller Industrieanlagenbau KG)

voestalpine heavy plate used in the Kaunertal pumped-storage power plant (© Kremsmüller Industrieanlagenbau KG)


Volkmar Held