Executive Summary

• Chris Cutler, Riello UPS Business Development Manager, pens this article around data centre UPS efficiency and explores how silicon carbide can switch things up.
• It’s not a new player to the game, but it brings increased power density, higher efficiency, thermal stability, enhanced durability and faster switching response.
• While silicon carbide-based UPS systems typically carry a higher upfront price than traditional IGBT designs, the long-term picture tells a different story

 

The data centre landscape continues to evolve at an extraordinary pace. The rapid rollout of hyperscale facilities and the surge in AI-driven computing are pushing rack densities and power requirements to new highs.

Globally, data centre power consumption is estimated to boom from 460 TWh in 2024 to more than 1,000 TWh by 2030. For comparison, the annual demand for power in the UK is roughly 320 TWh!

Alongside this growth, operators must contend with fluctuating load patterns, escalating energy costs, ongoing transition to a decentralised electricity grid, and increasing regulatory and corporate pressures to cut carbon emissions. Together, these factors are reshaping expectations of critical power infrastructure.

These converging challenges are forcing a rethink of traditional uninterruptible power supply (UPS) design. Manufacturers must continue to deliver absolute reliability – still the core purpose of a UPS – while also enabling greater efficiency, flexibility, and long-term sustainability.

Building On Established Technologies

Historically, uninterruptible power supplies have been manufactured using silicon-based Insulated Gate Bipolar Transistors (IGBTs), a well-established, proven, and cost-effective technology.

Technological advances such as the shift from two-level to three-level inverter architectures and improved filtering techniques have allowed for incremental gains in efficiency.

Yet incremental improvements are no longer sufficient. The operational realities of modern data centres, particularly those supporting AI workloads, require more substantial innovation. This is where silicon carbide (SiC) semiconductors can make a meaningful impact.

How Does Silicon Carbide Change The Game?

It goes without saying that silicon carbide isn’t a new technology, what with its widespread adoption in the electric vehicle industry, which has provided a good testing ground for its qualities. But for UPS manufacturers in particular, it does offer several inherent advantages compared to silicon-based IGBT:

• Reduced Switching Losses & Higher Efficiency: SiC components exhibit lower electrical resistance, resulting in reduced energy losses, which helps to maximise the overall efficiency of the UPS.
• Increased Power Density: the technology enables increased power density, making it possible to design more compact and lightweight UPS systems without compromising on overall power capacity.
• Improved Thermal Stability: SiC can operate at higher temperatures than IGBTs, translating to a broader operational range and reduced cooling demands. IGBTs require larger heat sinks as they dissipate more energy.
• Faster Switching Response: SiC’s faster switching capabilities result in a more responsive UPS, crucial for handling the rapidly fluctuating load conditions typically found in modern data centres, particularly those dealing specifically with AI applications.
• Enhanced Durability: the robustness of SiC and its ability to withstand high surge currents or voltage spikes reduces overall wear and tear, leading to extended component and UPS lifecycles, as well as reducing maintenance needs.

Before we move on to demonstrate the practical benefits of how these characteristics can impact on a UPS’s performance, it is important to acknowledge that silicon carbide components do take anywhere from 4-6 times the energy to manufacture.

This obviously means increased production costs and the amount of CO2 generated. However, these factors are more than offset by the overall energy savings across the lifecycle of the UPS, as we’ll go on to explore now.

Turning Technological Innovation Into Practical Performance

Riello UPS harnessed the untapped potential of SiC with our Multi Power2 range. The evolution of our modular UPS offering, the series comes in three versions: MP2 (300-500-600 kW versions), Scalable M2S (1000-1250-1600 kW versions), and our new model M2X, which protects up to 120 kW and is designed with smaller data centres in mind.

All these versions are based around high-density power modules incorporating SiC components. The result is class-leading efficiency of up to 98.1% in online double-conversion mode, delivering tangible reductions in energy consumption and operating costs.

Beyond these topline efficiency gains, SiC’s improved durability enhances the UPS’s ability to cope with rapidly fluctuating AI workloads, while also improving long-term reliability.

For example, with a typical UPS you’ll need to swap out the capacitors at service life year 5-7. Over the course of a system with a 15-year total lifespan, that’s two or even potentially three swap-outs, which cost money and engineer time, not to mention the environmental impact of safely disposing with the old components. But with the durability of SiC it is realistic to go through the entire lifespan of the UPS without having to replace the capacitors at all, cutting maintenance and disposal costs.

And don’t forget all the inherent advantages a modular UPS offers too. You’ve got that ‘pay as you grow’ scalability that allows a data centre to right-size at initial installation, then add extra modules or cabinets to increase power as and when its load requirements change. Then there are the hot-swappable power modules that ensure zero-downtime maintenance.

Measuring The Financial & Environmental Impact

Efficiency gains from a UPS manufactured with SiC semiconductors translate directly into significant cost and carbon savings. For example, in a facility operating at a 3.2 MW load, upgrading from a UPS operating at 96% efficiency to one achieving 98% efficiency could result in:

• More than 840,000 kWh of energy savings per year
• Approximately £133,000 reduction in annual electricity costs
• Around £2.5 million saved over a 15-year operating life
• Roughly 196 tonnes of CO₂ emissions are avoided each year

Then if you add in aspects such as the lifelong components and not having to regularly swap out capacitors, a typical data centre could save an additional £80,000 to £120,000 in maintenance costs alone over the lifespan of the UPS, too.

Even with a 3-5% increase in initial cost from using SiC power modules, you can see that the return on investment remains high.

Summarising Silicon Carbide’s Benefits For UPS

While silicon carbide-based UPS systems typically carry a higher upfront price than traditional IGBT designs, the long-term picture tells a different story. Lower cooling demands, reduced energy consumption, and extended component lifecycles combine to deliver a significantly improved Total Cost of Ownership.

Silicon carbide may not be a universal solution yet, but it is rapidly becoming a critical enabler for the next generation of power infrastructure. As efficiency expectations rise and AI workloads continue to reshape demand, SiC is set to play a central role in how UPS manufacturers support the data centres of tomorrow.