Designing for the Next Heatwave: How ClimateVision Helps Build Resilient Data Centers

Data center cooling systems are a critical component of the infrastructure, responsible for maintaining safe operational temperatures for servers and other equipment. When these systems fail, data centers face severe risks, including immediate shutdowns or even physical damage. Such disruptions directly impact the availability, causing cascading effects on businesses and customers reliant on these systems. 

To mitigate these risks, cooling systems are generally designed to withstand extreme external temperatures. Operators usually rely on historical temperature records close to the data center location to define these parameters, assuming that past weather data is representative of future conditions. Climate change, however, makes this assumption unreliable, especially as data centers are often built with a lifespan of several decades.  

In this case study, we’ll explore how operators use ClimateVision, Callendar’s climate impact assessment tool, to future-proof their infrastructure and design data centers that are ready for the next record-breaking heatwave.

Indoor temperature control is vital to ensure the performance of data centers

Case study: how data centers failure during the 2022 UK heatwave crippled London hospitals

In July 2022, the UK experienced an unprecedented heatwave, with temperatures in London exceeding 42°C - far beyond historical records. Cooling systems at two major NHS data centers failed under the strain, crippling IT infrastructure across several hospitals.

Previously, the highest temperature recorded in the UK was 38.7°C in 2019. As a result, British data centers’ cooling systems were typically designed for maximum ambient temperatures ranging between 35°C and 40°C, with older sites sometimes based on thresholds below 35°C. On July 19, 2022, those limits were shattered, overwhelming the cooling systems of two data centers operated by the National Health Service (NHS). This led to operational shutdowns, causing disruptions such as delayed access to patient records, interruptions to medical procedures and compromised emergency services.

During the 2022 heatwave, two NHS data centers failed, affecting over 23,000 health professionals. Full restoration took three months, and the hospital trust spent £1.4 million on technology services to respond to the incident, with indirect costs likely far higher.

Other data centers in the London area also faced disruptions during this heatwave, with shutdowns reported by major tech companies, including Google and Oracle. These incidents highlighted the broader vulnerability of IT infrastructures. They demonstrate the risks of relying on technical designs based solely on historical weather records, which are quickly becoming obsolete in the context of climate change. 

Can We Anticipate Unprecedented Heatwaves? What the Science Tells Us

To build resilient infrastructures, operators must consider extreme temperatures representative of future climates over the lifespan of the installation. By incorporating climate projections, it is possible anticipate the increasing frequency and intensity of heatwaves and other climate-related risks. 

The current state-of-the-art approach relies on climate projections, which simulate future weather patterns accounting for greenhouse gases emissions scenarios and the effects of climate change. 

To ensure these projections are reliable at the local level, bias correction and downscaling techniques are employed. Bias correction adjusts simulation outputs to correct potential systematic errors, while downscaling translates broad regional projections into high-resolution data that reflect the specific geographic and climatic conditions of the project location. 

Although robust scientific methodologies are available to predict extreme heat in present and future climates, their adoption remains limited due to technical complexity.

Finally, extreme value analysis is used to quantify the likelihood of rare but impactful events. By statistically modeling tail events, this method allows to calculate temperature threshold corresponding to specific probabilities, such as the 1-in-50-year (or 2% annual probability) heatwave over the project lifespan. This enables data center operators to design infrastructure with the optimal level of resilience, balancing the need to prevent outages while avoiding over-investment. 

ClimateVision: Making Climate Science Work for IT Infrastructure Design

Callendar has incorporated best-in-class methodologies into its ClimateVision climate impacts assessment suite, empowering users with quick, reliable, and cost-effective evaluations of extreme temperatures for their project locations. 

The suite applies extreme value theory to both historical weather records and carefully prepared climate projections and provides an evaluation of 5-, 10-, 20-, 50-, and 100-year return temperatures. These analyses are performed across multiple time horizons, ensuring infrastructure and facilities are designed with consideration for an evolving climate over their entire operating lifespan. 

To address uncertainties in climate modeling and future emissions scenarios, ClimateVision adheres to current scientific best practices and offers multi-model and multi-scenario assessments. Extreme temperatures are evaluated for several emission scenarios and a diverse set of climate simulations, providing a robust, comprehensive evaluation tailored to each location. The quality of the corrected data, the statistical significance of trends and the robustness of multi-model assessments are tested using state-of-the-art methodologies. 

ClimateVision is based on the latest IPCC climate projections and available for next-day delivery at any location in the world. Interested ? Contact us and start protecting your critical infrastructures against climate change today!

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Build with confidence! Callendar has provided climate projections and impact assessment, including extreme temperatures evaluation, to a variety of large industrial projects in Europe, Africa and Middle East. 

In addition, Callendar is a consulting expert to the French Nuclear Safety Agency’s extreme temperature working group.