Pumped storage Plants

Pumped storage plants 

Pumped storage is the economically and environmentally most developed form of storing energy during base-load phases while making this energy available to the grid for peaking supply needs and system regulation. This has been done by Voith since this technology was invented.

Today, over 400 Voith pumped storage units have been installed worldwide with a combined output of well over 24 000 MW.

Pumped storage plants can be configured in several different ways. Reversible machine sets or ternary systems that consist of separate generating and pumping equipment may be installed.


Ternary systems

Ternary systems consist of a motor-generator and a seperate turbine (typically Francis or Pelton) and pump set. As two seperate hydraulic machines, the rotational direction of the motor-generator can be the same in both operational modes. This results in considerable commercial value for the power plant's operation. For the switch between turbine and pump operation, a clutch operable at standstill, a starting turbine or a synchronizing tourque converter can be provided.

Torque converter

The torque converter provides extremely short switching times between turbine and pump operation.Within seconds the storage pump can be connected or seperated from the shaft system.

Reversible machine sets

Reversible machine sets consist of a motor-generator and a reversible pump-turbine that works either as a pump or as a turbine depending on the direction of rotation. This desgin allows for compact power houses that save equipment and civil costs. With a wide range of specific speeds, pump-turbines can be installed at sites with heads from less than 50 to more than 800 m, and with unit capacities ranging from less than 10 to over 500 MW. 


With the use of an asynchronous motor-generator the rotational speed of the pump-turbine can be varied. Thus, the pump capacity can be adjusted to using just the currently available amount of energy. This allows for highly efficient stabilization of the grid.

Whether a reversible pump-turbine, or a turbine and pump combination, these machines have proven to be extremely durable. In many cases, they have performed reliably for several decades.


Relevant products

Here you can find a short version of our study about pumped storage plants   

Selected references

Bath County, USA


Voith modernized the six turbines of the Bath County (Virginia) pumped storage power station, making it once more the largest in the world. read more

Guangzhou, China


Voith fitted one of the world's most powerful pumped storage power plants with four units consisting of pump turbines and motor generators. read more

Limberg II & Kopswerk II, Austria

The Kopswerk II and Limberg II pumped storage power plants in Austria produce clean electricity and help to contribute to the stability of Europe's electricity network; Voith delivered their critical components. read more

Frades II, Portugal 


With Voith's variable-speed pump turbines this milestone in pumped storage technology will promote the development of renewable energy in Portugal. read more

Tai'An, China


Voith installed a large turnkey pumped storage power plant in the Chinese Shandong province. read more

Ingula, South Africa


Voith supplies all of the electro-mechanical equipment for this South African pumped storage project which will be used to stabilize the entire electricity network.   read more

Goldisthal, Germany


Voith equipped this large, modern pumped storage power station with variable-speed pump turbines, as well as a large proportion of its automation and control systems. read more