Exactly one year ago forumNordic published a groundbreaking story about a the early startup days of Steady Energy’s innovations for a small nuclear plant for district heating – this is the link.
Now one year later progress has been rapid and exciting with new commercial contracts being signed for the first bunch of plants
Founded in June 2023 as a spin-out from Finland’s state-owned VTT Technical Research Centre, Steady Energy has quickly positioned itself as a frontrunner in the emerging field of small modular nuclear reactors (SMRs) for district heating. The company’s flagship technology, the LDR-50 (Low-temperature District heating Reactor), is specifically engineered to replace fossil fuel-based heating systems with a compact, low-pressure nuclear alternative that produces zero operational carbon emissions.
The LDR-50 reactor operates at a maximum temperature of 160°C and a pressure of just 8 bar—comparable to an espresso machine—significantly simplifying its mechanical design and safety features. Unlike traditional nuclear reactors that generate electricity, the LDR-50 is optimized purely for heat generation. Its passive safety system, which includes double-walled containment and underground installation in fortified caverns, allows the unit to operate safely within urban environments. According to company officials, this novel approach could help displace up to 10% of global CO₂ emissions by targeting the 250 TWh of district heating in the EU currently sourced from fossil fuels.
Over the past 12 months, Steady Energy has made significant commercial strides. It has secured letters of intent with major municipal utilities including HELEN Oy in Helsinki and Kuopion Energia Oy in Kuopio. The plant in Helsinki will be contructed underground in a now discommissioned coal power plant cavern in the centre of Helsinki!
These agreements encompass plans for more than 10 LDR-50 units to be deployed in Finland, leveraging existing district heating infrastructure. The company also reports a growing international interest, with a sales pipeline now valued at over $1.5 billion and plans underway to export to other European markets.
To support this rapid expansion, Steady Energy has attracted major financial backing. In March 2024, the company completed a €10 million funding round led by Lifeline Ventures and Yes VC. This initial round supported the company’s research and early commercial development. Then, in March 2025, Steady Energy announced a €22 million Series B round, led by Copenhagen-based 92 Ventures, with continued support from existing investors. The new funding is earmarked for the construction of a full-scale pilot plant in Helsinki, slated to begin in the second half of 2025.
This momentum has not gone unnoticed. In early 2025, Forbes named Steady Energy’s technology one of its “7 Big Ideas for 2025,” highlighting its practicality, scalability, and critical role in achieving Europe’s carbon reduction targets.
With experienced leadership drawn from the Finnish nuclear sector and backing from both public and private sectors, Steady Energy is advancing steadily toward deploying the world’s first commercial small nuclear heating reactors. Its blend of low-cost, safe, and carbon-free energy solutions may represent a turning point in the global effort to decarbonize urban infrastructure.
Photo credit: From Steady Energy
