How Power Electronics Cut Generator Run Hours in Data Centers. 7 Min Read. Battery energy storage systems with grid-forming power electronics are enabling ride through and fast response at hyperscale campusesGetty. AI-scale computing and tightening ESG expectations are pushing data centers to rethink diesel generators as the default for resilience. Part One of this series examined battery energy storage systems (BESS) as a practical alternative to diesel generators. This second installment maps how advanced power electronics – grid-forming inverters, AI-capable UPS, high-voltage DC architectures, and universal damping controls – can minimize or replace diesel run hours while preserving uptime and improving grid stability. The aim is not to eliminate diesel but to use it sparingly with a right-sized generator tier reserved for extreme conditions.. From Diesel First to Diesel Last. Historically, facilities turned to diesel within seconds of sensing instability. However, BESS paired with intelligent power conversion can deliver instant ride-through, stabilize voltage and frequency, and buffer both the data center and the grid from abrupt load swings – especially those caused by AI training. As a result, many disturbances that previously would have triggered facilities onto diesel can now be handled electrically.. Related:Virginia Tightens Data Center Generator Permitting as Community Scrutiny Grows. The stakes are no longer theoretical. As noted in Part One, a 2025 minor grid fault in Virginia caused numerous data centers to trip offline simultaneously, triggering the activation of backup generators. The resulting aggregate loss – about 1.5 GW – forced the system operator to take emergency action to avoid a wider outage. Short, high-magnitude transients from large AI loads can also destabilize networks, degrade insulation, overheat transformers, cause arcing, and even ignite fires.. Grid-Forming Inverters and AI-Ready UPS. Inverters have long handled DC/AC conversion in data centers. A new class – grid-forming (GFM) inverters – adds the ability to regulate voltage and frequency, stabilize weak grids, and support islanded operations when facilities run off-grid. Recent systems provide bidirectional support: they shield the data center from low-quality power or transient faults, and, critically, buffer the grid from abrupt AI-driven load changes.. ON.energy’s AI UPS illustrates the trend. Each 3.5 MW unit places a power conversion system (PCS) on both sides of a battery bank, with a transformer for grid and facility integration. Depending on the load, it can provide 1 to 8 hours of backup power. The company reports roughly 3 GW of these units in operation or under construction. Because the system is sited outside the white space, it eliminates the need for a dedicated internal UPS room, frees floor space for compute, and facilitates higher-voltage architectures.. Related:California Data Center Health Impacts ‘Tripled in Four Years’. According to the company, testing by the National Laboratory of the Rockies (NLR) on a new power-electronics platform for large AI data centers showed ON.energy’s AI UPS riding through massive load swings without faltering – conditions that might otherwise have triggered diesel backup systems.. “The scale of modern data centers could lead to load swings of 1 GW multiple times per minute, which creates frequency variations and oscillations that the grid can’t handle,” said ON.energy CTO Ricardo de Azevedo. “Batteries act like a reservoir of energy as well as a shock absorber should there be any disturbances on the grid or from the data center.”. High-Voltage Architectures and LVRT for AI Workloads. Dimaag.ai has proposed an 800 VDC power architecture designed to isolate the grid from the large cyclic variations created by AI training and to deliver low-voltage ride-through (LVRT), the ability to remain connected during short-term voltage dips. Presented to ERCOT in Texas, the approach combines a battery solution called “Zenius” with control software (Zifer).. “Next year’s release of the Vera Rubin Chipset by Nvidia coincides with the requirement for data centers to be ready for 800 VDC architecture,” said Sadha Kameswaran, vice president of business development at Dimaag.ai. “The large load datacenters that are being built cannot meet grid requirements for power fluctuation and LVRT.”. Related:Outage Report: AI Boom Threatens Years of Data Center Resiliency Gains. The company contends its design addresses grid stability while meeting core data center needs – peak shaving, backup power, and demand response – in one system. It is currently under evaluation by a few hyperscalers.. “There is no viable solution out there today that is grid-compliant while meeting all data center requirements,” Kameswaran said. “Our solution uses a smaller footprint, has the lowest total cost of ownership and is more power efficient because of no physical switching and a minimum number of AC to DC conversions.”. Universal Damping and Grid-Scale Stability. Stability becomes even more challenging as operators interconnect new data centers alongside renewable assets. Today, planners attempt to anticipate devices and oscillation modes that might enter the system and tune damping controllers for specific scenarios. Nonetheless, unforeseen conditions can trigger outages, as was likely the case with the Portugal-Spain grid event in April 2025.. A consultancy in Denmark, Ramboll, proposes a universal damping approach to reduce the risk. Its Universal Damping (UD) STATCOM acts as a “shock absorber” for transmission systems, using power electronics and batteries to detect voltage oscillations, absorb their energy, and convert it back into usable power rather than dissipating it. Ramboll is in talks with OEMs, utilities, and investors to commercialize the technology.. UD-STATCOM actively damps oscillations across a broad frequency range, regardless of their source. Its controller continuously monitors AC voltage, identifies oscillatory components beyond the fundamental frequency, and adjusts current proportionally to provide positive damping. By acting like an adaptive resistor that returns absorbed energy to the grid, it aims to improve resilience while lowering integration costs.. “It is difficult handling the ever-changing power generation and load patterns, especially when the grid is outdated,” said Mojtaba Mohaddes, senior technical manager at Ramboll and inventor of the innovation. “By preventing oscillations at the source, the Universal Damping STATCOM can help utilities and data centers by providing uninterrupted power.”. Mohaddes noted that UD-STATCOM can be deployed as a software upgrade to existing STATCOMs, offering a lower-cost path to stability than major infrastructure overhauls.. “AI data centers, specifically, are a significant source of frequent oscillations because large language model training applications require an incredible number of processors running weeks on end,” he said. “The amount of power consumed is not steady or flat but is akin to thousands of random home appliances being turned off and on multiple times a second.”. Turning UPS and BESS into Grid Assets. Advanced controls are also transforming UPS and BESS from static, emergency-only resources into dynamic distributed energy resources (DER).. Eaton has augmented its lithium-ion UPS platform with software and controls – the Power Xpert 9395P with EnergyAware technology – so facilities can provide and receive energy, support frequency regulation, and generate revenue, while preserving critical-load protection. Tested at Microsoft’s Innovation Center in Boydton, Virginia, and evaluated by regional transmission organization PJM, the UPS reportedly exceeded operator requirements for accuracy, response time, and precision on a self-scored test, demonstrating its viability as a DER.. Vertiv’s EnergyCore Grid – Battery Energy Storage System integrates utility demand management, voltage and frequency services, and load management with UL9540A-tested lithium-ion batteries to deliver utility-scale storage for mission-critical environments. By smoothing load profiles and enabling seamless transitions to an always-on, battery-enabled power supply, organizations can reduce operating expenses such as peak demand charges while maintaining resilience.. The Emerging Data Center-Grid Compact. As AI scales, the boundary between the data center and the grid asset is blurring. New power electronics – GFM inverters, AI-capable UPS, high-voltage DC architectures, and universal damping STATCOMS – are reshaping how facilities interact with electric networks, emphasizing ride-through, fast response, and grid services as much as on-site protection.. “In the future, you don’t have a data center or a power plant,” said Sean James, director of energy research at Microsoft. “It’s something in the middle as an asset for the grid rather than just a load. Data centers are going to have to provide AI smoothing, add more flexibility, and meet new grid requirements such as low-voltage ride-through.”. In Part Three of this series about diesel backup alternatives, we focus on natural gas reciprocating engines, gas turbines, and steam turbines fed by packaged boilers. In Part Four, we explore technologies that are less mature or not yet widely deployed but are gaining attention.. About the Author
