News

Construction is progressing rapidly at Utilitas’ new zero-emission heat pump plant on the Paljassaare peninsula in Tallinn. This is Estonia’s first heat pump plant to utilize treated wastewater and seawater, with Maru Metall responsible for the design, production, and delivery of the station’s steel structures.

For Maru Metall, the greatest engineering challenge lay within the building. During the design phase, it became clear that the load-bearing steel frame was the easier part of the manufacturer’s job for this massive structure, explained Madis Tuuling, Member of the Board at Maru Metall. According to him, the real challenge consisted of designing the complex network of pipe supports required to accommodate the state-of-the-art Friotherm AG heat pumps and the extensive piping they require.

Upon completion, the plant will cover nearly a fifth of the annual heat consumption of Tallinn’s district heating network. Utilitas began construction of the wastewater and seawater heat pump plant and the seawater pumping station in May 2025. The emission-free plant will start providing heat to Tallinn’s district heating network in the second half of 2026. Once operational, the plant is estimated to reduce the CO₂ emissions of Tallinn’s heat supply by 100,000 tonnes per year, and the share of imported fossil fuel will fall to less than 10 per cent.

For Maru Group, participation in the Paljassaare project is a natural continuation of previous strategic energy projects. For example, we have previously built all three synchronous compensator stations operating in Estonia, which are critical for ensuring the stability of the Estonian electricity grid.

 

 

Location of pipe supports within the model and the model with pipe supports.

During the topping-out ceremony in March, Maru Metall’s designers saw the network of steel elements they had modeled on screen materialize in real life.