Digital infrastructure, predominantly supported by data centres, is facing increasing pressure due to rising ambient temperatures and growing internal heat loads caused by the use of AI applications and more powerful hardware. Mathias Franke, Head of Data Centre Consulting at Drees & Sommer SE, points out that heat, long considered a secondary aspect, has now become a central challenge for many operators. Insufficient adaptation of cooling capacities can lead to operational disruptions and costly outages.
The sector is experiencing significant growth: since 2010, the installed data centre capacity in Germany has more than doubled, reaching over 2,730 megawatts in 2024. The German Federal Ministry for Economic Affairs and Climate Action forecasts a further increase to over 4,800 megawatts by 2030, which would represent an increase of approximately 75 per cent within six years. The national data centre strategy, adopted in March 2026, even aims for a doubling of capacities by 2030. This growth is primarily driven by cloud services and AI applications, but it simultaneously increases the vulnerability of digital infrastructure to extreme weather events. An analysis by First Street from June 2026 shows that 54 per cent of global data centre capacity is located in regions experiencing chronic heat or drought stress.
AI applications are fundamentally transforming the demands on data centres, as they not only consume more energy but also emit significantly more heat into their surroundings. This circumstance requires operators to give greater consideration to planning and operation. A study involving the University of Cambridge, published in March 2026, quantifies the average heat island effect of AI data centres at around two degrees Celsius, with peak values of up to 9.1 degrees Celsius. Worldwide, over 340 million people could be affected by the so-called 'Data Heat Island Effect'. Heat-related outages are not necessarily unavoidable; early alignment of cooling, power supply and operational processes with extreme weather conditions can reduce risks.
Experts from Drees & Sommer emphasise the need for proactive planning of both location and technology, as well as establishing clear operational measures for heatwaves. Studies, including the 'Prometheus' study by Google and the University of Pennsylvania, indicate that data centres will need to increase their cooling capacity by an average of eleven per cent by 2044 to maintain the current risk of failure; in particularly exposed locations, the demand could be up to 48 per cent. Mathias Franke recommends incorporating the projected extreme temperatures of the next 20 years into cooling plans and allowing for a safety buffer of four Kelvin, as future forecasts are likely to show even higher temperatures.
In addition to IT infrastructure, emergency power systems must also be prepared for future heat extremes, as a failure of their cooling could jeopardise the entire power supply and thus data centre operations. Operationally, shifting compute-intensive tasks such as backups or data migrations to cooler night-time hours offers a way to relieve cooling systems. If one cooling system fails, a second system must immediately take over. The emergency power supply must secure not only the servers but also the cooling systems. Microgrids, which connect local power grids with their own energy sources and storage, can continue to supply critical systems during disruptions to the public grid.
For server cabinets reaching capacities of around 50 kilowatts and more, pure air cooling often reaches its limits, as many data centres were originally designed for significantly lower power densities. Mathias Franke explains that water-based cooling systems enable much more efficient heat dissipation due to water's higher heat capacity and are therefore increasingly used for high power densities, especially for AI applications and high-performance computers. For moderate power densities, air cooling remains a practical solution. Hybrid systems allow for a gradual transition to liquid cooling in particularly high-performance areas, ensuring reliable cooling even at higher outdoor temperatures. For new data centres commencing operation since July 2026, the Energy Efficiency Act tightens efficiency requirements.
