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Scalable cities


Combined Efficient Large Scale Integrated Urban Systems


EU contribution
Total costs
Funding programme
2- Large scale systems for urban area heating and/or cooling supply


To increase energy efficiency in EU, CELSIUS helped cities across Europe to develop secure, affordable and low carbon district heating and cooling solutions that form part of the city's wider energy system. The focus was on maximising the use of waste heat or secondary heat within a city by capturing and using it in the heating system. Participating cities were Gothenburg (Sweden), London (United Kingdom), Rotterdam (the Netherlands), Cologne (Germany) and Genoa (Italy). 



Project demonstration sites


CELSIUS aimed to establish an intelligent heating system covering virtually all the households and commercial buildings in the high density areas of a city, along with an energy-efficient district cooling system for its commercial customers. These systems make use of a range of excess heat sources all created within the city during the course of an average operational day, for example, from various industrial and data centre activities, heat extracted from sewage and bio-based heating.

CELSIUS took a holistic approach to overcoming technical, social, political and economic barriers to market roll-out of heating and cooling systems through its delivery of 10 new innovative demonstrators and the operation of more than 20 existing demonstrators. Categorized into system integration, sustainable production, storage, end user and infrastructure, the demonstrators illustrated technical and deployment innovation as well as innovative approaches to financing and stakeholder engagement.

One of the goals of CELSIUS was to recruit 50 New CELSIUS Cities and to provide them with relevant support, advice and guidance to help gain support for, establish, construct or ultimately grow district heating and cooling systems in their cities. 56 CELSIUS member cities signed up.

CELSIUS City not only consumes much less fossil fuel-generated energy than a traditional European city, but it also plays a fundamental role in supporting the resilience and security of the electricity network by effectively utilising existing network capacity for connecting new distributed generation and for providing grid balancing.

Energy Carriers

  • Heat/district heat
  • Waste heat

Energy Systems Types

  • Infrastructure & System Integration
  • DHC extension
  • Storage
  • Thermal Storage

Thematic Field

  • Energy System(s) Integration


CELSIUS_Common monitoring methodology and data structure
CELSIUS_Report on KPI values