Kierikki hydropower plant

PVO-Vesivoima, a subsidiary of Pohjolan Voima Oyj, has decided to invest in a 3 MW ultracapacitor energy storage project. Based at the Kierikki hydropower plant along the river Iijoki, the project will be a first for PVO-Vesivoima and a pilot for energy storage technology that can extend the service life of the power plant. Fast-acting balancing power will be needed to stabilise the power grid as the energy markets transform. PVO-Vesivoima aims to build an ultracapacitor facility at all its hydropower plants. The construction of the pilot project is set to begin in 2024.

The significant growth of weather-dependent energy production, especially wind power, has changed the energy markets. The power grid requires control capability to maintain its stability during shifts in electricity demand and production. The hydropower plant’s ultracapacitor facility can provide an extremely very rapid response to these changes. Its control capability improves the stability of the power grid and ensures the security of electricity supply.

“This investment is directly connected to the growth of renewable energy. By developing the control features of our plants and investing in technology, we’re doing our part to support the transition. Stronger control capability stabilises the distribution system, which is increasingly important for Finland,” says Markus Pyykönen, Production Development Manager at Pohjolan Voima.

Ultracapacitors are high-power short-term energy storage devices. They are electrostatic devices that can deliver power in under a second without a material loss in storage capacity. In this case, they are working with a hydropower plant. This solution is necessary for responding to sudden shifts in the power grid’s electricity supply: ultracapacitors store electricity and can release it rapidly for a few minutes.

“We’re very happy with the investment decision. This project is an important part of the digitisation of our hydropower plants along the river Iijoki and the overall development of our operating systems. We can pilot technology that will extend the service life of our power plant. The stress on the turbine will be reduced by the ultracapacitor facility because it can respond in under a second, taking the load off the hydropower plant’s mechanical systems,” says Antti-Pekka Sipola, Development Manager at PVO-Vesivoima.

The Kierikki ultracapacitor project is planned to be completed at the end of 2024. The pilot project at the Kierikki power plant will be used to gather practical experience for potential larger investments. PVO-Vesivoima plans to build an energy storage based on ultracapacitors at all its hydropower plants.

Additional information:

Markus Pyykönen, Production Development Manager, Pohjolan Voima Oyj, tel. +358 40 840 2428,

Antti-Pekka Sipola, Development Manager, PVO-Vesivoima Oy, tel. +358 50 303 8615,

PVO-Vesivoima Oy produces electricity with its hydropower plants on the Iijoki, Kemijoki and Kokemäenjoki rivers. The average total annual energy production output of the company is 1.7 TWh. The company is part of the Pohjolan Voima Group.; X (formerly Twitter): @PVOVesivoima