Vaasan Voima secures €5.8 million for thermal storage expansion in Vaskiluoto

Vaasan Voima has received over €5.8 million from the Ministry of Economic Affairs and Employment to develop an underground thermal storage facility. The investment support aims to enhance the temperature and capacity of the thermal storage located in Vaskiluoto. Janne Österback, the CEO of Vaasan Voima, stated that this investment focuses on a heat energy storage system launched in Vaskiluoto in 2020.

The facility consists of two former oil tanks carved into rock, which can store a total of 210,000 cubic meters of hot water for district heating. In 2023, the technology for the thermal energy storage was upgraded, allowing its capacity to increase to 11 gigawatt-hours, making it one of the largest energy storage facilities in Finland by volume.

The current goal is to expand the thermal energy storage capacity from 11 to 17 gigawatt-hours. This would be achieved by raising the temperature of the stored water from 95 degrees Celsius to over its boiling point of 100 degrees Celsius, according to Österback.

The company has not yet finalized its decision on a larger investment, estimated at around €20 million. The board of Vaasan Voima will make the investment decision soon, currently under discussion with the owners. Vaasan Voima is a wholly-owned subsidiary of EPV Energia, and its district heating production meets over 60% of the needs of the city of Vaasa.