Urban cooling networks: a future infrastructure for climate adaptation in cities

Faced with this challenge, cooling buildings and public spaces is becoming a strategic priority for local authorities. Individual air conditioning, long the preferred solution, is now reaching its energy and environmental limits.

As a collective and efficient alternative, urban cooling networks are still not widely deployed in Europe, but are expected to play an increasing role in local energy transition and climate adaptation strategies.

Heat waves: a new structural constraint for cities

Rising average temperatures and the increasing frequency of heatwaves have direct impacts on public health, user comfort, and the quality of urban services. While local authorities have undertaken greening and thermal renovation projects, these measures are insufficient to meet the growing need for cooling, particularly for commercial buildings and sensitive facilities (hospitals, nursing homes, schools).

In this context, individual air conditioning has emerged as a short-term solution. However, it fuels a problematic cycle: heat emissions that exacerbate urban heat islands, massive use of polluting refrigerants, and increased electricity consumption during peak summer periods. Cooling thus becomes a fully-fledged energy and urban issue, requiring structural solutions.

From building to city: what a district cooling network changes

In terms of energy efficiency, district cooling networks offer significantly better performance than stand-alone air conditioners: their overall efficiency is 1,5 to 3 times higher, depending on the configuration, for equivalent service. This results in a significant reduction in electricity consumption.

Centralized production also allows for much better containment of refrigerants (approximately 0,5% leakage compared to 10% for individual machines) by concentrating their use on a few installations controlled and maintained by professionals.

Finally, at the urban scale, the removal of outdoor units on the facade or roof eliminates visual and noise pollution, while limiting the release of diffuse heat that warms the public space: unlike individual systems, the heat extracted from buildings is mostly dissipated via natural environments (geothermal, rivers, sea) or via optimized exchange devices (cooling towers), rather than being released directly into the ambient air.

Cooling networks are thus emerging as tools that are simultaneously energy-related, urban and environmental, serving sustainable performance.

A development potential that is still largely untapped

In France, district cooling networks remain underdeveloped compared to district heating networks: around fifty networks are in operation, delivering approximately 1 TWh per year. This is a modest volume considering the growing challenges related to urban cooling.

The prospects are nonetheless significant. Public forecasts anticipate a doubling, or even a tripling, of delivered volumes by 2030-2035. This dynamic is based on several converging factors: intensification of heat waves, pressure on summer electricity consumption and the rise of territorial energy planning policies, which now integrate cooling alongside heating.

The European directive on energy efficiency reinforces this approach by asking local authorities to include heating and cooling needs in their local strategies; a direction which is gradually being reflected in French planning documents and major urban projects.

As the world's leading operator of district cooling, ENGIE currently operates 22 networks in France, in cities such as Paris, Marseille, Levallois-Perret, and Cannes, and also has international operations. These projects illustrate the diversity of contexts in which the solution can be deployed: the density of the Parisian urban fabric, seawater-based heating and cooling in the Mediterranean basin, and shallow geothermal energy in eco-districts such as those in Issy-les-Moulineaux and the Matabiau urban development zone in Toulouse.

From the regulatory framework to the reality of projects

The development of district cooling networks is now supported by a clearer regulatory and economic framework. Legal recognition of "efficient" district cooling networks, aligned with that of district heating networks, opens access to public support mechanisms.

Several recent measures improve the competitiveness of projects: extension of the Heat Fund to include cooling, creation of dedicated CEE (Energy Savings Certificates) sheets for connecting buildings, application of a reduced VAT rate of 5,5% on the supply of networked cooling since January 1, 2026. All these developments put an end to a historical asymmetry between heating and cooling in public energy policies.

Beyond the financial arrangements, a district cooling network project remains a demanding operation. It requires securing several parameters simultaneously: a sufficient customer base, land suitable for the installation of the facilities, local acceptance of the works, and careful integration with existing or future urban projects.

At ENGIE, this project engineering translates into end-to-end support for local areas, from preliminary studies to operation, with dedicated teams and solutions tailored to each context. Cold storage, mobilization of local renewable resources (seawater, rivers, geothermal energy), and digitalization of operations: these are all areas that will further strengthen the performance and resilience of tomorrow's networks.

[1] Source: Current scenario of the National Low Carbon Strategy of the Ministry of Energy Transition

Opinion piece by Benoît Brient, Director of Network Development at ENGIE, Local Energy Infrastructures (LinkedIn).