Finnish energy company Helen and Austrian AI data center developer OnZero have signed an agreement to utilise waste heat from a new data center in Helsinki’s district heating network. The planned facility could generate more than 500,000 megawatt hours of heat annually, enough to meet the heating needs of around 70,000 flats.
Helen is continuing to expand its use of waste heat as part of the transformation of its district heating production. The company has agreed with OnZero Finland Oy to connect waste heat from a new data center to Helsinki’s district heating network. The recovery of waste heat from the data center is scheduled to begin in 2027. Once fully operational, the facility could supply more than 500,000 megawatt hours of heat to the district heating network each year.
Waste Heat to Support the Clean Transition
“By harnessing waste heat from OnZero’s data center for Helsinki’s district heating system, we can reduce the need for combustion-based heat production in a cost-effective way while ensuring that district heating remains a competitive and attractive heating solution for customers in the future. Our goal is to phase out combustion-based energy production by 2040, and the increased use of waste heat is an effective way of supporting that transition,” says Tuukka
Toivonen, COO, Strategy and M&A at Helen.
“We founded OnZero with a clear objective: to lower the cost of AI by combining high-performance AI infrastructure with the efficient recovery and productive use of compute heat. Our agreement with Helen demonstrates how this approach can work in practice – turning heat generated by AI computing into a valuable resource for Helsinki’s district heating network,” said Ali Siddiqui, CEO of OnZero.
Long Experience
Helen has been integrating data center waste heat into Helsinki’s district heating system and supplying the recovered heat to residents since 2010. Data center projects that make extensive use of waste heat reduce the overall burden on the energy system and place less additional demand on the electricity grid. The agreement with OnZero further strengthens the role of waste heat as a source of heat for Helsinki.
