As European cities work hard to decarbonise, they are also grappling with unprecedented heatwaves driven by rising temperatures. The challenge of extreme heat is no longer a distant threat but a present-day reality, making sustainable and clean cooling solutions an urgent priority.
Between 2010 and 2019, final energy use for cooling in residential buildings across the eurozone tripled, and forecasts suggest that by 2050, cooling alone could account for up to 9% of total energy use. Local governments now face a critical question: how to cool buildings and public spaces without compromising climate objectives, so they can protect communities and keep their cities healthy, liveable, and dynamic in a hotter world.
What options are available for sustainable cooling?
While air conditioning has become the most common response, it is not a long-term solution. Conventional AC systems are highly energy-intensive, release additional heat into surrounding streets, and drive-up greenhouse gas emissions. Paradoxically, they make cities even hotter and lock them into fossil fuel dependence. As more households and businesses install individual units, the risk of maladaptation grows, intensifying urban heat islands, straining electricity grids and undermining decarbonisation goals.
This is where district cooling comes in. A central facility produces chilled water and distributes it through an underground network to multiple buildings. District cooling offers clear benefits for cities aiming to safeguard public health and cut emissions. It provides efficient cooling for all building types, uses less energy than individual air conditioning, and can be powered by local, low-carbon sources such as sea or river water, geothermal energy, or waste heat.
The Energy Efficiency Directive (EED) now requires cities with more than 45,000 inhabitants to develop local heating and cooling plans. With rising temperatures, the cooling element of these plans can no longer be overlooked. Such plans offer a good opportunity for cities to explore district cooling solutions in their cities, as they develop, expand or renovate district heating networks.
This legislative momentum is mirrored by market trends. According to Euroheat & Power’s 2025 District Heating and Cooling Market Outlook, district cooling infrastructure in Europe expanded by over 3% in 2023, with major growth planned in cities across the continent. The technology’s potential is especially strong in Southern Europe, including countries like Spain, where district cooling remains relatively new but increasingly relevant.
Where Cities Heat Detox Meets Cities Refresh
Over the past year, through the Cities Heat Detox and Cities Refresh campaigns, the Covenant of Mayors has been highlighting how cities are taking action both to decarbonise heating and cooling systems and to become more resilient to heat. Sustainable district cooling sits exactly at the intersection of these two goals, offering a compelling pathway to equip cities for a hotter climate.
Local planning for district cooling has become an essential piece of the puzzle. By moving away from polluting cooling technologies, cities can embrace collective, clean, place-based solutions that reduce emissions and reimagine city infrastructure for the decades ahead.
Below, we explore how diverse European cities – from north to south – are embracing district cooling in innovative ways.
Marseille: Harnessing the Sea to Detox the Heat
In southern Europe, where heatwaves are becoming longer and more intense, Marseille is pioneering a new kind of sea-side resilience. Through its Massileo and Thassalia district cooling networks, the city leverages seawater to provide thermal energy for both cooling and heating. Combined, these systems span 4.4 km and have already cut CO₂ emissions by 80%. The networks are being actively expanded, reinforcing Marseille’s commitment to climate-neutral infrastructure.
Read more about Marseille’s Sea-Side Detox.
Paris: Cooling with the Seine
The Fraîcheur de Paris network is one of Europe’s largest district cooling systems, using cold water from the Seine and geothermal wells to provide efficient, low-carbon cooling. It is connected to many of the city’s most iconic buildings, including the Louvre, as well as major commercial areas. With six interconnected generation plants and integrated energy storage, the system has achieved remarkable performance gains: it delivers over 100% energy efficiency, reduces electricity consumption by 35%, cuts refrigerant emissions by 90%, lowers chemical use by 80%, and decreases CO₂ emissions by 50%.
Find out more about the Fraîcheur de Paris network.
Tallinn: Cooling a Northern City getting warmer
Once primarily concerned with heating, Estonia’s capital Tallinn now faces hotter summers. Responding early, the city began constructing a carbon-neutral district cooling network in 2019, adding approximately one kilometre per year in the city centre. By embedding cooling within its broader strategy for climate neutrality, Tallinn is planning ahead to ensure comfort and sustainability go hand in hand.
Read more about Tallinn’s Way to Climate Neutrality.
Tartu: The Baltics’ cooling innovation hub
Before Tallinn, Tartu introduced the first district cooling network in the Baltics in 2016, powered by free cooling from the Emajõgi river and solar electricity. The plant includes heat pumps that recover and reuse excess heat from buildings, decreasing the need for electricity by 70% and cutting CO₂ emissions by 6,000 tons per year. The solution provides a cleaner, quieter, and space-efficient alternative for property owners and sets a benchmark for mid-sized cities.
Read more about Tartu, the first district solution in the Baltics.
Gothenburg and Helsinki: Combined district heating and cooling
In Gothenburg, where 80% of homes rely on district heating, district cooling is now expanding from the city centre with plans to double in size over the next decade. Meanwhile, Helsinki demonstrates the power of integration. Its combined district heating and cooling system captures solar-heated excess energy and reinjects it into the grid, with over 80% of district cooling energy produced from energy from otherwise unused sources. This circular model reduces waste and optimises energy use year-round.
Find out more about Gothenburg’s Journey to Fossil-Free District Heating and Cooling.
Read more about Helsinki’s Combined District Heating and Cooling System.
Munich and Vienna: Ambitious cooling with ambitious heating
In central Europe, cities like Vienna and Munich are also developing innovative systems that combine cooling and heating for year-round efficiency. In Vienna, a new district cooling centre at the MedUni campus uses chillers powered by electricity and district heating to produce cold water for cooling. The system captures excess indoor heat and, via heat pumps, repurposes it for winter heating – creating a seasonally efficient energy loop.
Find out more about Vienna’s district cooling plant at MedUniCampus.
Munich has been developing its own district cooling network since 2014, operated by the municipal utility Stadtwerke München (SWM). Drawing from the Isar River and underground streams, the system combines direct cooling via heat exchangers and heat pumps. Integrated with the city’s heating infrastructure, it reduces energy use by 50 to 70% compared to decentralised cooling systems, highlighting the efficiency of joint thermal planning.
Read more about Munich’s district cooling from groundwater.
Barcelona: District Cooling in Southern Europe
Barcelona operates one of Southern Europe’s largest thermal energy distribution systems through DistriClima, which includes three production plants—one of which is cooled using seawater. The network delivers both heating and cooling to hundreds of buildings across the city, including hospitals, public institutions, and commercial areas. By centralising thermal energy supply and making use of renewable and recovered energy sources, Barcelona’s district cooling system not only improves energy efficiency but also helps reduce emissions and alleviate the urban heat island effect.
Dive into Barcelona’s DistriClima network.
Details
- Publication date
- 7 August 2025