On 26 September 2025, the cornerstone ceremony of Europe’s largest electric boiler plant marked the start of construction in the Hanasaari energy block in Helsinki. Helen’s new facility will be built next to the decommissioned coal-fired power plant, right in the heart of the city.
Thanks to this investment, an even greater share of district heating will be produced without carbon dioxide emissions. Together with A-Insinöörit and Elomatic, we are proud to be responsible for the design and implementation of this significant clean energy initiative.
The cornerstone was laid by the Mayor of Helsinki, Daniel Sazonov, and Helen’s CEO Olli Sirkka together with the project team. The new plant and its integrated thermal energy storage units represent a major milestone for the City of Helsinki – and a source of pride for us as designers and builders.
In collaboration with Elomatic, we are bringing together best practices from industry, energy production, and construction.
“This project is a once-in-a-lifetime opportunity for our entire design team. The central location in Helsinki has not only been an opportunity but also a challenge. The architectural goals and demanding technical solutions have required extensive planning and coordination. In designing the buildings, we have focused on creating solutions that soften the industrial scale while adding subtle depth and dimension to the structures,” says our lead designer, architect Juha Lehtonen from ONE Architects.
The new facility, comprising four electric boilers, will be built next to the decommissioned coal-fired power plant and is scheduled for completion during the 2026–2027 heating season. The project will also include two heat storage units. Once operational, the electric boiler plant will be capable of meeting the heating demand of an area equivalent to two Lauttasaari districts.
Further information:
Juha Lehtonen , Lead architect, industrial and premises
tel. 040 088 3330
juha.lehtonen@onearchitects.fi