Sustainable data centers: 3 ways to get there

A challenge to innovate in sustainable data centers

Hyperscale and multi-tenant data center developers tend to be savvy about the low-carbon possibilities. Their decision-makers know about the latest innovations and are passionate about hitting their sustainability targets. This sets them apart. The tech sector wants to push innovation while managing risks in the mission-critical building’s structural systems. They want low-carbon options that perform well.

We often design and engineer diverse structures for hyperscale and multi-tenant data center clients. Their request? They want us to study and evaluate cutting-edge systems and new ideas for innovation and risk.

These developers are challenging us as structural designers to take a deeper look at the materials we use. They want us to consider less carbon-intensive materials and to use more of those that store carbon. Together, we engage with subject matter experts to push the edge of sustainability in structural design. With these important goals in mind, we must also remain confident that the innovative material or approach will perform.

We are working with our clients and pushing structural innovation in the design of sustainable data centers. Here are three areas of focus. 

1. Mass-timber structures

Mass timber is a renewable resource. When we use it as a structural component, it can greatly contribute to the reduction and storage of carbon emissions. Some developers who want sustainable data centers are choosing mass timber for their building projects. They often use it for administrative and support spaces where humans interact with the material. These facilities are great entry points for mass timber because these buildings are modest in size with reasonable structural demands. People tend to enjoy being in environments with wooden structural materials, so it makes sense to apply them to workspaces.

Data halls occupy large footprints on hyperscale data center campuses. These structures must support specialized and intense loads. The most ambitious companies want to push the envelope with the structural materials in these buildings. They are starting to use mass timber, along with structural concrete and steel in these buildings. We are working with them on sustainable structures for data halls and mission-critical facilities.

The broader industry is pushing the use of mass timber in a variety of ways. We’re already using glulam mass timber as an additional option to steel or concrete columns and beams. CLT (cross-laminated timber) floor and roof panels are viable options to concrete slabs, precast planks, composite floor systems, and roof decks. Each of these systems offers something worth evaluating. These include flexible, durable, or sustainable options. In the coming years, we expect to see more timber and hybrid timber wall panels and hybrid timber roofs. We will continue to develop balanced structural and sustainable solutions for our friends in the tech sector.

As we combine mass timber or CLT with low-carbon concrete, we find more ways to innovate. We already see CLT panels mixed with concrete to achieve hardness like concrete or composite concrete and steel systems. We’re excited to see how using mass timber and CLT can expand the industry’s sustainable options for floors, roofs, columns, bracing, and wall panels.

Studies show that using mass timber in design and construction can save a lot of embodied carbon. Transition Accelerator, a think tank, says that replacing typical materials with mass timber could cut embodied carbon by 40 percent. One study found that a mass timber building had 198 kilograms CO2 equivalent emissions per square meter. That compares with 243 kilograms for a steel structure.

2. Low-carbon concrete mixes

Concrete is durable, strong, and reliable. And data centers will keep using it for many structural components. However, the tech sector is now looking for advanced solutions for concrete mix designs in sustainable data centers.  

That’s because cement manufacturing is responsible for about 8 percent of global CO2 emissions. Without change, the World Economic Forum predicts growing emissions. At the current pace, emissions from cement will reach 3.8 billion tons per year by the middle of the century.

Decades ago, the building industry started using fly ash in concrete mixes to reduce carbon emissions compared to the traditional Portland cement mix. This became the new standard. For years, we used 25 percent fly ash in our concrete to reduce its carbon intensity. Now, we often use type IL cements. Here, we offset some of the carbon-intensive cement with limestone, which lowers concrete’s embodied carbon. We also push the limits of cementitious substitution with fly ash and other pozzolans. Solutions such as CarbonCure, which sequester carbon, are gaining traction in the building industry.

Large data center developers want to substitute more material in their concrete. Our clients are asking us to look at mixes that swap from 50 to 90 percent of the standard materials in concrete with lower-carbon options. These high-performing mixes use reactants and other additives that take a substance like fly ash, silica fume, or slag and supercharge its cementitious properties. By using these mixes, we can reduce the carbon intensity of the concrete in buildings on campus. Where should we use these materials? Administrative buildings or server suites are good options. As an early adopter, the data center industry could influence those outside mission-critical facilities to look into low-carbon concrete.

3. Optimization in design and construction

As discussed, these are carbon-conscious clients. So, they are also pushing for innovation and optimization in design, engineering, and construction.

In the recent past, the quality of engineering in these buildings was measured by robustness or strength. But today, we aim to balance robustness with sustainability. How? By looking to optimize engineering and construction. We need to use materials efficiently, by applying the right amount of the right materials for the job. And we do this while maintaining structural integrity.

To optimize for the best result, we need tailored analyses and sometimes buy-in from the project team. Working closely with the data center developers allows us to share the reasons for our approaches to fine tune the strategy. For instance, our preference for lighter structural systems, like open web bar joists, lowers the need for steel investment. This matches the sustainability goals of many of these organizations.

We design these advanced mission-critical facilities to be flexible. Over the years, their electrical and cooling systems will be updated or replaced. And they should continue to perform well. As technology evolves, we expect these sustainable data center campus buildings will also improve. By designing them to accept upgrades with limited rework, we reduce the carbon investment required down the road.

Optimizing lighter structures with steel, concrete, or mass timber has other benefits, too. For example, lighter building structures often have

• Smaller foundations
• Simpler seismic systems
• Fewer site-preparation requirements

By cutting the carbon cost in these systems, we can lower the overall energy consumption of construction.

Global data centers

We are seeing hyperscale and multi-tenant developers push for these sustainable data centers in North America. But really, this has global impact. The supply chain in North America offers us a wide array of options in terms of steel and concrete products. But what about areas where the manufacturing supply chain is more limited?

Mass timber and CLT products have many benefits. They are made in factories; they are lightweight; and they can be shipped via cargo ship, rail, or truck with low-energy impact. Small construction crews can put them together relatively quickly. The prefabrication and transportability of mass timber make it an appealing option for mission-critical facility design and construction globally. This is especially true in regions where the supply chain is not as strong. Portable or shippable low-emissions concrete mixes would boost sustainable construction on a global scale. When we optimize structural designs, we can reduce the materials we use and align the new facilities with sustainability goals.

It’s inspiring to work in a sector that’s leading the way in decarbonization. We are excited to explore the options for structural materials and building optimization. Ultimately, we’ll help data center developers meet their sustainability goals. It won’t be long before today’s frontier, mass timber and low-carbon concrete, will become a new standard. And we can’t wait to see what comes next.