BESS, Grid-Interactive UPS, FLISR, and Advanced Protection Systems
As hyperscale and AI-driven data centers expand into 100 to 1GW+ campuses, their relationship with the electric grid has undergone a profound transformation. Once viewed as inflexible, high-demand loads with near-zero tolerance for outages, data centers are now emerging as critical partners in grid stability and resilience. Through technologies such as Battery Energy Storage Systems (BESS), grid-interactive UPS systems, advanced synchronization controls, and FLISR automation, modern facilities are helping utilities manage volatility, integrate renewables, and protect critical infrastructure. This evolution is central to the mission of sustainable digital infrastructure and increasingly essential to the future of the grid.
Data Centers as Active Grid Participants
The traditional model cast data centers as passive consumers: large, steady loads that required constant power quality and uninterrupted service. Today’s facilities incorporate sophisticated electrical topologies that allow them to absorb disturbances, provide fast-response support, and even participate in demand response and ancillary service markets. This shift aligns with broader decarbonization trends, where distributed, controllable assets are vital for balancing renewable generation and maintaining reliability.
Utilities now see data centers not as stressors but as stabilizing nodes. Their proximity to load centers, their advanced power electronics, and their ability to respond in milliseconds make them uniquely valuable in a grid increasingly shaped by intermittent generation and electrification.
Battery Energy Storage Systems: A Stability Backbone
Battery Energy Storage Systems have become foundational to the modern data center. These systems, often ranging from 10 to 300 MW per building or campus, serve dual purposes: they protect the facility’s internal operations and provide external support to the grid.
BESS contributes to frequency regulation by injecting or absorbing power within milliseconds, helping maintain the grid’s 60 Hz frequency during disturbances. It also supports voltage stability through reactive power control, a function especially important in regions with high renewable penetration. During peak demand periods, BESS enables load shifting and peak shaving, reducing strain on transmission networks. In some architectures, BESS can even support black start capabilities or allow a data center to operate as a microgrid during outages.
The U.S. Department of Energy’s Energy Storage Grand Challenge (2023) highlights the growing importance of distributed BESS for frequency regulation and grid stability, underscoring why utilities increasingly value data center storage assets.
Managing Sub-Synchronous Oscillations and Harmonics
Large clusters of power electronics, such as AI servers, cooling systems, and UPS inverters, can introduce sub-synchronous oscillations and harmonics into the grid. These disturbances, if unmanaged, can propagate through feeders and substations, affecting other customers and utility equipment.
Modern data centers mitigate these risks through advanced synchronization controls. Grid-forming inverters help stabilize weak grids, while phase-balancing algorithms and active damping controls prevent oscillations. Real-time harmonic filtering ensures that rapid load ramps, such as those generated during AI training cycles, do not degrade power quality.
IEEE’s Harmonic Control in High-Power Electronics (2022) provides a technical foundation for these mitigation strategies, emphasizing the importance of coordinated inverter behavior in large-scale digital infrastructure.
Grid-Interactive UPS Systems: From Backup to DER
UPS systems have traditionally served as isolated buffers, protecting IT loads from disturbances. Today, they are increasingly grid-interactive, functioning as distributed energy resources capable of supporting utility operations.
A grid-interactive UPS can provide ride-through support during short disturbances without drawing additional power from the grid. Some systems can inject power for seconds or minutes, offering fast frequency response during instability. When paired with BESS, UPS systems can participate in demand response programs, reducing grid draw during emergencies and acting as controllable load.
EPRI’s Grid-Interactive Data Center UPS Systems (2021) documents how these systems are becoming integral to utility planning, offering ancillary services without requiring new infrastructure.
FLISR: Fault Location, Isolation, and Service Restoration
FLISR technology—Fault Location, Isolation, and Service Restoration—has long been used by utilities to improve reliability. Increasingly, data centers integrate FLISR capabilities directly into their campuses and utility interconnects.
FLISR systems detect faults instantly, isolate the affected segment, and reroute power through alternate feeders. This automation allows service to be restored within seconds rather than minutes or hours. For data centers, which often sit on critical feeders, FLISR reduces outage duration, improves reliability metrics such as SAIDI and SAIFI, and minimizes the impact on surrounding customers.
NREL’s Distribution Automation and FLISR Technologies (2020) highlights how automated fault management is becoming essential for modern distribution networks—especially those serving large digital loads.
Additional Components Strengthening Grid Interaction
Beyond BESS, UPS, and FLISR, data centers deploy a suite of technologies that collectively enhance grid resilience. STATCOMs and SVCs provide reactive power support, maintaining voltage stability. Harmonic filters ensure power quality across feeders. Advanced relaying and protection schemes prevent backfeed and fault propagation. Microgrid controllers coordinate generators, BESS, and load during disturbances. AI-driven forecasting tools help utilities anticipate demand ramps and plan for peak periods.
IEEE’s Microgrid Protection and Control Standards (2024) outlines the importance of these integrated systems, emphasizing how coordinated control strategies improve both facility and grid performance.
A New Strategic Partnership Between Utilities and Data Centers
The relationship between utilities and data centers is evolving into a strategic partnership. Joint planning for substation upgrades, coordinated dispatch of BESS and UPS assets, shared telemetry for real-time visibility, and co-development of microgrid strategies are becoming standard practice. Data centers increasingly participate in ancillary service markets, providing frequency regulation, spinning reserve, and voltage support.
Utility Dive’s How Hyperscale Data Centers Are Reshaping Grid Planning (2023) notes that utilities now treat data centers as essential grid participants, not merely customers.
References:
U.S. Department of Energy – Energy Storage Grand Challenge
A comprehensive DOE initiative outlining the role of distributed BESS in grid stability, frequency regulation, and renewable integration. https://www.energy.gov/energy-storage-grand-challenge (energy.gov in Bing)
IEEE – Harmonic Control in High-Power Electronics
IEEE publishes multiple papers and standards on harmonic mitigation, inverter behavior, and sub-synchronous oscillation control. (Access requires IEEE membership or institutional login.) https://ieeexplore.ieee.org/search/searchresult.jsp?queryText=harmonic%20control%20high%20power%20electronics (ieeexplore.ieee.org in Bing)
EPRI – Grid-Interactive Data Center UPS Systems
EPRI’s research on how UPS systems can provide grid services, fast frequency response, and ride-through support. https://www.epri.com/research/products/000000003002020777 (epri.com in Bing)
NREL – Distribution Automation & FLISR Technologies
NREL’s foundational work on FLISR, automated feeder switching, and distribution-level reliability improvements. https://www.nrel.gov/grid/distribution-automation.html (nrel.gov in Bing)
IEEE – Microgrid Protection and Control Standards
IEEE’s standards and guidance for microgrid protection, coordination, and inverter-based resource behavior. https://standards.ieee.org/ieee/2030.7/6314/ (standards.ieee.org in Bing)
Utility Dive – How Hyperscale Data Centers Are Reshaping Grid Planning
A widely cited industry article on how large data centers influence utility planning, transmission upgrades, and grid strategy. https://www.utilitydive.com/news/how-hyperscale-data-centers-are-reshaping-grid-planning/641040/ (utilitydive.com in Bing)