Heat storage technology piloted by the City of Lappeenranta now generates steam for the Finnish industry

The city of Lappeenranta has been piloting a heat storage technology in a district heating facility, developed by Elstor Oy. In this solution cheap off-peak electricity is stored in a heat reservoir, which can then be released as heat, replacing fossil fuels. Lappeenranta's Environmental Director, Ilkka Räsänen, states that this approach leads to cost savings on fuel and a reduction in greenhouse gas and particulate emissions.

The heat storage pilot facility in Lappeenranta's Selkäharju area has been producing steam for Kaskein Marja Oy since the fall of 2021, completely replacing the use of natural gas.

Now, other Finnish industries have also recognized the value of this technology. In May 2023, Herkkumaa Oy in Hämeenlinna implemented Elstor's 10 MWh double unit, estimated to reduce the company's emissions by approximately 790 tons of CO2e annually. In June, Turku-based Oy Roberts Ab made an investment decision to adopt the heat storage technology.

Mikko Roberts, CEO of Oy Roberts Ab, views this as a necessary and inspiring investment in the future. Ilkka Räsänen, the Environmental Director, is delighted to see the technology pioneered by the city gaining traction and becoming useful across Finland. He believes that in the future, heat storage technology can be utilized not only for steam production but also in district heating.

The city's initiative accelerated the adoption of heat storage technology.

Lappeenranta's pilot project started in 2018 as part of the six-year EU Life project "Towards Carbon-Neutral Municipalities and Regions." The project aimed to implement practical climate actions and create conditions for low-carbon production and consumption. Elstor Oy's heat storage technology from Lappeenranta was an excellent fit for this endeavor.

Through the city's project, Elstor Oy was able to develop and test its technology on an industrial scale on a fast schedule, according to Kari Suninen, the CEO of Elstor Oy. He emphasizes that without the pilot project, it would have been impossible to develop heat storage technology at such a fast pace. Moreover, the experiences gained from the pilot project allowed for further development of the technology, now in serial production as a heat storage unit used in industrial process steam production.

A single 5 MWh Elstor base unit can save up to 480 tons of carbon dioxide annually. Additionally, this solution contributes to the conditions for renewable electricity production through frequency regulation, demand response, and balancing electricity markets.