GEA and Utilitas are driving Tallinn’s clean energy transition with the installation of four high-efficiency heat pumps at the Väo energy complex, including the first commissioned innovative GEA Grasso L XHP screw compressor-based heat pump.
Supporting the city’s goal of net-zero emissions by 2050, the system recovers waste heat from biomass CHP to reduce fossil fuel use, cut CO₂ emissions, and deliver reliable heating to 8,000 homes and businesses.
With 60 per cent of Estonia’s buildings relying on district heating, ensuring a reliable, affordable, and environmentally responsible heat supply is critical.
Utilitas Tallinn CEO, Robert Kitt, said the company provides heat to 400,000 people, about one-third of the population.
“Our challenge is to secure supply during cold winters, keep prices stable, and minimise environmental impact. We’ve set an ambitious target to become carbon neutral by 2030,” he said.
“The Väo energy complex is a crucial step towards that goal, utilising biomass at highly efficient CHPs, sun, waste heat from the production of green hydrogen and GEA heat pump technology to optimise efficiency and sustainability.
“Choosing to work with GEA for this installation is entirely in line with that strategy: We knew we had a reliable partner who would offer an efficient and sustainable solution.”
The four heat pumps from GEA are a significant addition to the already highly efficient biomass CHP system.
The system comprises three GEA Grasso LT screw compressors (model XB) and the new 70 bar GEA Grasso L XHP screw compressor, which is based on GEA Grasso technology that has been developed over decades.
Director of Sales (Baltics) at GEA Heating & Refrigeration Technologies, Mindaugas Lazdauskas, said these heat pumps ensure optimum performance by dynamically adjusting temperatures: 65°C in summer, 85°C in winter and up to 95°C if required.
“With the new GEA Grasso L XHP, we offer high temperature performance and efficiency that make large decarbonisation projects like the one in Tallinn a reality,” he said.
Product manager for Screw Compressors at GEA Heating & Refrigeration Technologies, Ron Hoffmann, said it is the efficiency and capacity at high pressure that make it the ideal solution for Utilitas' ambition for a cleaner and more efficient district heating network.
The natural refrigerant ammonia further improves the sustainability of GEA heat pumps.
"Ammonia has been a safe and effective refrigerant for over 150 years," Hoffmann said.
"Its thermodynamic properties and long service life make it a long-term solution that is in line with evolving refrigerant regulations.”
“With the second-stage flue gas condensers, we are making the cogeneration plant more efficient," Indrek Sang, project team leader at Utilitas Tallinn, said.
"We take the excess low-temperature heat of up to 35 °C and use the heat pumps to raise it to a stable 82 °C for the district heating network,” Sang said.
This process significantly improves energy recovery and reduces reliance on back-up boilers, cutting emissions while optimising resource consumption.
Since their installation in 2023, the GEA heat pumps have shown significant environmental and economic benefits.
"In the first heating season, we produced around 80,000 MWh of heating energy," Sang said.
"Thanks to the heat pumps, we use less natural gas and reduce CO₂ emissions by 20,000 tonnes per year."
In addition to the reduction in emissions, the efficiency gains are also remarkable.
"We have achieved a coefficient of performance (COP) of more than four," Sang said.
“These successes make the Väo energy complex a model for other cities that want to modernise their district heating infrastructure.”
Tallinn’s achievement is part of a growing portfolio of more than 50 GEA-supported district heating projects across Europe and North America.
From seawater heat in Copenhagen to mine water in Gateshead and waste heat from the London Underground, GEA’s heat pump solutions are key enablers to cities’ decarbonisation efforts worldwide.
“The European transition towards resource-efficient energy starts with the cities,” Hoffmann said.
“As urban populations grow and energy demands rise, projects like Väo set the standard for district heating’s future and stand as a powerful example of how innovation and collaboration can drive meaningful change.”
With a focus on efficiency, reliability and environmental responsibility, GEA remains a trusted partner in engineering solutions that not only heat homes but also reduce CO₂ emissions.