> ## Content Index > Fetch the complete content index at: https://www.techstories.co/llms.txt > Use this file to discover other available public pages before exploring further. # Four reasons data centres shouldn't write off DRUPS - URL: https://www.techstories.co/four-reasons-data-centres-shouldnt-write-off-drups/ - Published: 2026-09-10T09:44:20.000Z - Updated: 2026-09-12T18:16:15.000Z - Description: A veteran engineer on kinetic backup's real-world advantages. - Author: Paul Mah - Tags: Data Centres DRUPS have fallen out of fashion in data centres. But they continue to offer compelling advantages, including for cutting-edge AI workloads. Here's what I learned. I [recently wrote](https://www.techstories.co/the-ups-that-doesnt-use-batteries-at-all/) about the diesel rotary uninterruptible power supply (DRUPS), a power backup system that stores kinetic energy instead of relying on chemical lead-acid or lithium-ion batteries. But how do DRUPS hold up in the real world? To find out, I spoke with a local lead engineer with decades of experience designing and operating DRUPS deployments in data centres. Here are four things I learned. ### Lower lifecycle cost One common complaint about DRUPS is the maintenance they require. But they are not subject to battery replacement cycles, which carry capital and disposal costs that add up over the years. The result is a lower cost when plotted over a DRUPS' expected field life of up to 30 years. The gap is even more apparent in markets where the grid is less reliable, since heavily cycled batteries need replacing more frequently. ### Reduced asset count Cost is only part of the picture. To guard against failures, data centres are built with redundant systems, and here DRUPS have an edge too. With a DRUPS, it is possible to design a high-voltage ring bus for resilience with fewer units. By comparison, a redundant static uninterruptible power supply (UPS) equivalent would typically require significantly more installed capacity, potentially up to twice the asset count depending on how it's designed. ### More flexibility in placement Recent battery-related data centre fires have driven changes in data centre fire regulations. In Singapore, the latest Singapore Civil Defence Force (SCDF) codes effectively mandate that energy storage systems sit on the ground level. DRUPS are not subject to that requirement. And because they are more tolerant of their operating environments, they offer greater flexibility in where they can be placed within the data centre. ### Higher power factor Utilities don't let a data centre use 100% of its grid connection; they hold back a margin. The share of the connection that does end up as useful power is the power factor (PF), and it is set by the grid operator. A DRUPS puts a rotating alternator between the grid and the load, so the utility sees a much cleaner draw. That gives operators a strong technical case to negotiate a higher PF, which translates into more MW that can be sold to customers. ### The bottom line None of this makes DRUPS universally better. For one, they can be less cost-effective when facility-level utilisation comes in lower than projected. But for other facilities, they can yield better cost savings and reliability. Interestingly, DRUPS are a great fit for AI workloads, which often see large clusters of GPUs swing from near idle to full draw and back in milliseconds. As power constraints tighten and AI loads grow, DRUPS are worth a fresh look.