UPM Energy is a major provider of hydropower and balancing power. The company is now the first energy company to pilot energy storage with an ultracapacitor in a system comprising two hydropower plants. The power plants are Katerma in Kuhmo and Kallioinen in Sotkamo, both located along the Ontojoki River in Finland.
Ultracapacitors are electrostatic devices that can quickly discharge or charge large amounts of electrical power. Combined with a hydropower plant, an ultracapacitor can react in milliseconds to meet the rapid demand for power. It acts as the fast-responding part of the system, responding to the power demand first minutes, after which hydropower takes the lead and continues to balance the electricity system. The combination has the potential to be a new type of asset for the reserve market.
"It is not just the ultracapacitor that plays a key role in our project, but the whole system", says Juha Haromo, Development Manager at UPM Energy.
The whole system is managed and optimised by an Advanced Process Control (APC) system that uses modern digital functions and automation. In the case of Ontojoki, it can be thought of as a river balance, which is optimised by the Katerma and Kallioinen power plants.
Capacitor technology has already existed and is used for a variety of solutions. We are using it as a system to bring new reserves to the market and to enable more renewable energy in the grid", explains Haromo.
It is the combination that makes the project inventive and impactful. It is the world's first combination of a hydropower system and an ultracapacitor.
Hydropower plays an important role in balancing the grid
The rapidly increasing supply of weather-dependent power generation, such as wind and solar power, has also added to the challenge of keeping the Nordic electricity grid stable. With the increasing amount of renewable energy, more balancing power capability is needed to quickly rebalance the grid when needed.
"The project will extend the capabilities of the traditional Nordic balancing power, , hydropower, so that it will be able to serve the needs of the electricity grid in the future with a significant amount of renewable energy", says Haromo.
"Innovations and projects like this are a prerequisite for adding renewable energy to the system. Without this kind of development, the electricity system would not function in the future", he stresses.
Construction started in autumn 2021, and the ultracapacitor was connected to the Katerma and Kallioinen power plants in mid-June 2022.
The ultracapacitor will have no impact on dam safety, water use or the aquatic environment. The addition of an ultracapacitor to a hydropower plant will reduce the need for rapid response control of the plant and allows smooth power generation control.
UPM Energy is developing new solutions for emission-free power generation and the changing needs of the electricity market. The future energy market requires smart solutions and investments to ensure system flexibility and reliability.