As cities around Europe push forward with their ambitious climate goals, the 2025 Covenant of Mayors Award shines a light on the pioneers leading the way in heating and cooling decarbonisation. This year’s finalists display cities and towns of all sizes, from all corners of Europe, and showcase an impressive array of innovative, sustainable, and inclusive projects — each proving that the journey to fossil-free heating is well underway. Let’s meet the cities and towns setting an example for the rest of the continent.
Vilnius, Lithuania
As the 2025 European Green Capital, Vilnius is making bold strides toward a fossil-free future. One of its standout projects is the construction and implementation of the largest absorption heat pump in the Baltic region. This ambitious initiative enhances the efficiency of the city’s district heating system by utilising waste heat from production processes, reducing dependence on biomass and natural gas. The heat pump recovers enough energy to heat 26 A++ energy-class apartment buildings annually — a game-changer in sustainable urban heating.
Vaasa, Finland
The 2026 EU Green Leaf winner, Vaasa, is repurposing its 1970s-era oil storage caverns for renewable heat storage. The innovative Vaskiluoto heat storage project allows the city to store surplus renewable energy and deliver it when demand and costs are highest. This initiative has already reduced Vaasa’s reliance on coal in its heating system by over 30%, marking a significant step toward fossil-fuel independence.
Delve into Vaasa’s case study.
Lappeenranta, Finland
Lappeenranta is pushing for carbon-neutrality by 2030 by embracing low-cost, low-emission electricity to transform its district heating. The city’s efficient thermal energy storage uses AI-driven algorithms to optimise charging based on capacity, electricity prices, and heat demand. This pilot project enhances affordability and resilience, ensuring equitable access to essential energy services.
Besançon, France
Known as the greenest city in France, Besançon is taking a socially inclusive approach to heat decarbonisation. By expanding its district heating system, the city provides local, renewable energy at prices 30% lower than market rates. This network prioritises energy-poor areas, ensuring that the benefits of clean, affordable heating reach vulnerable populations and support the fight against energy poverty.
Campi Salentina, Italy
Despite its small size, Campi Salentina is making a huge impact with its GROWS project, supported by significant funding from the European Investment Bank. By installing high-efficiency heat pumps, the city improves the thermal comfort of its residents while promoting healthier heating, creating jobs in the electricity and construction sectors, and strengthening the local economy.
Porto, Portugal
Porto is kickstarting its heat detox journey in the vibrant Asprela district through the “Asprela + Sustentável” project — the city’s first Energy Community. By generating electricity from photovoltaic panels, the project supplies 180 families with the energy needed to heat and cool their homes. This innovative approach not only reduces emissions but also helps combat energy poverty in the area.
Vari-Voula-Vouliagmeni, Greece
This Mediterranean municipality is modernising its heating infrastructure by replacing outdated oil boilers with high-efficiency heat pumps and installing photovoltaic panels to power these new systems in public buildings. Prioritising schools, Vari-Voula-Vouliagmeni ensures better thermal comfort for students and teachers while advancing the city’s decarbonisation efforts.
Domokos, Greece
Domokos is advancing its decarbonisation journey by installing air-to-water heat pumps for heating and reversible heat pumps for cooling in offices and classrooms. By prioritising schools, the town is creating healthier and more sustainable learning environments while setting an example for broader public infrastructure.
Get inspired by their journey.
Mechelen, Belgium
Mechelen is developing sustainable district heating by harnessing geothermal energy and waste heat from water treatment. Once considered unfeasible, these projects are now supported by emerging pilot initiatives and new heat zoning maps. The city’s Heat Coalition brings together over 25 organisations from government, businesses, and civil society to drive this transformation.
Reykjavik, Iceland
A long-time leader in renewable heating, Reykjavik has been using geothermal energy since the 1970s. Now, the city is taking its decarbonisation journey even further with the Silverstone Project — an initiative to transform the Hellisheidi ON Power Plant into one of the world’s first near-zero carbon geothermal facilities. This project underscores Reykjavik’s continued commitment to clean energy innovation.
These cities exemplify what’s possible when ambition, innovation, and community engagement come together. As we celebrate the finalists of the 2025 Covenant of Mayors Award, we look forward to seeing how their efforts inspire others across Europe and beyond. Our finalists join an already rich set of heat decarbonisation stories from our Cities Heat Detox campaign.
Stay tuned for the announcement of this year’s three winners next week!
Details
- Publication date
- 3 March 2025