UPM Energy commissions grid-balancing ultracapacitor at Kuusankoski hydropower plant

(UPM, Helsinki, November 4, 2025 at 10.00 EET) – UPM Energy’s ultracapacitor at the Kuusankoski hydropower plant is now operational. The six-megawatt device stores energy and provides balancing power to the electricity grid. The need for fast and flexible balancing power has increased with the growing use of renewable, weather-dependent forms of energy, such as wind and solar power. The investment, announced in August 2024, triples UPM’s ultracapacitor capacity and further strengthens the ability of hydropower to balance the electricity grid quickly and efficiently.

The ultracapacitor system can respond to the balancing needs of the electricity grid in a fraction of a second. Short-term energy storage provides additional capacity for balancing power production, which is increasingly important as the volatility of electricity production increases. Ultracapacitors are maintenance-free and have a significantly longer lifespan than batteries, making them ideal for sustainable energy solutions.

“The need for reserves has tripled in the last five years, due to the increased share of weather-dependent energy sources. When there is no wind, balancing power is needed, which hydropower in particular can provide. Ultracapacitors provide a rapid response, complementing hydropower and helping to ensure the durability of power plants. This means more balancing power for the grid and better balance for the entire electricity system," says Juha Haromo, Development Manager at UPM Energy.

The Kuusankoski ultracapacitor leverages modern digital solutions and automation to optimize the ultracapacitor and hydropower system performance. This ensures that balancing power can be provided to the grid efficiently and reliably.

UPM Energy's first ultracapacitor was commissioned in 2022 at the Ontojoki hydropower plants. The plant was the world's first combination of a hydropower system and an ultracapacitor.

UPM Energy plays a significant role in electricity generation in Finland as Finland's second largest electricity producer, with 99% of its electricity production being emission-free.

For further information please contact:
Juha Haromo, Development manager, UPM Energy, tel. + 358 2041 66016
 

UPM, Media relations
Mon-Fri 9:00–16:00 EET
tel. +358 40 588 3284
[email protected]

UPM Energy
UPM Energy is the second largest electricity producer in Finland. We generate CO2-free electricity in our own and co-owned power plants. In 2024, our total electricity generation was 11.4 TWh. In addition, we sell electricity and its derivatives on the electricity market and explore the opportunities of energy transformation. 

UPM
UPM is a material solutions company, renewing products and entire value chains with an extensive portfolio of renewable fibres, advanced materials, decarbonization solutions, and communication papers. Our performance in sustainability has been recognized by third parties, including EcoVadis and the Dow Jones Sustainability Indices. We operate globally and employ approximately 15,800 people worldwide, with annual sales of approximately €10.3 billion. Our shares are listed on Nasdaq Helsinki Ltd.
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