Heat recovery in data centers faces challenges

The recovery of heat from data centers is often used as a justification for their presence in a region, but implementing this practice is complicated by various technical and organizational factors.

Data centers produce significant heat

Data centers, which house servers for cloud computing and AI, produce large amounts of heat as a byproduct of their operations. This heat is sometimes proposed to be recovered and reused as an energy-efficient measure.

Legal requirements and low compliance

In France, a law requires the most energy-intensive data centers to recover their emitted heat. However, only 0.1% of this heat is actually reused, far below the European average of 2 to 9%.

Challenges in implementation

Researcher Loup Cellard highlights several obstacles, including technical and geographical difficulties, as well as coordination issues between data center operators, local authorities, and energy companies. These challenges hinder the effective reuse of heat.

Industry transparency and research role

The data center industry is not known for transparency, and recent investigations have pointed out a lack of cooperation from European institutions. Academic research is seen as a key tool in addressing these issues and providing clarity on the subject.

Multiple stakeholders involved

Loup Cellard's research involved interviews with various stakeholders, including data center operators, energy companies, and public officials. These discussions revealed the complexities of integrating heat recovery into urban and rural planning.

Heat reuse as a marketing tool

Operators often use the promise of heat reuse to position themselves as environmentally responsible. However, the actual implementation of such projects remains difficult due to the need for coordination and investment.

Technical and economic barriers

Most data centers emit heat at temperatures too low for direct use in heating networks, which typically require temperatures above 60 °C. This often necessitates additional equipment, such as heat pumps, and raises questions about who should bear the costs.

Legal obligations and flexibility

Since December 2025, data centers in France must recover at least 20% of their unavoidable heat unless they can prove the project is not economically or technically feasible. This requirement highlights the ongoing challenges in meeting these legal standards.

Successful examples and future needs

Despite the challenges, some successful cases exist, such as an Equinix data center in Saint-Denis that supplies heat to local buildings. The report emphasizes the need for better planning and collaboration between stakeholders to achieve effective heat recovery.