This week, a power line failure occurred just outside Washington, DC, which typically allows the electrical grid to recover within seconds. However, this incident took over 10 minutes to stabilize due to a simultaneous shutdown of more than 3 gigawatts worth of power from data centers.
Data collected by Ting Labs, a startup utilizing an IoT sensor network, highlighted that the voltage across the PJM grid surged from Northern Virginia to Chicago as a result of this event. While the incident did not lead to a blackout, it did cause noticeable flickering of lights throughout the area, illustrating the significant impact large data centers can have on the grid — a trend that experts anticipate will occur more frequently.
Northern Virginia, part of the PJM territory, boasts the highest concentration of data centers globally. Ricardo de Azevedo, CTO of ON.Energy, described the situation as indicative of broader issues, pointing to similar events becoming increasingly common.
This recent occurrence resembled a similar incident from two years prior, also affecting the PJM grid, raising concerns about the potential for more severe disruptions if data centers do not adopt strategies to handle such power outages effectively. The PJM Interconnection is the largest grid operator in the United States, managing the electrical supply for 67 million customers across states from New Jersey to Illinois.
During this week's event, data centers quickly transitioned to backup power systems, leading to a rapid drop in demand of around 3.1 gigawatts within 30 seconds, according to PJM data. Although the grid initially showed signs of recovery, further load reductions caused it to take an additional 11 minutes to stabilize. The data centers that disconnected accounted for roughly 3% of PJM’s total demand at that time, as reported by Reuters.
While 3% may seem minor, the grid must maintain a delicate balance between supply and demand. An imbalance can lead to voltage fluctuations. While minor deviations can be tolerated, substantial changes can activate grid failsafes, resulting in disconnections.
As disturbances from the failed power line reached Northern Virginia data centers, they swiftly shifted to backup power, exacerbating the initial load drop and contributing to voltage instability that made lights flicker. Ali Zain Banatwala, a senior market models specialist at the Independent Electricity System Operator, mentioned that the affected data centers acted almost instantaneously, disconnecting in unison to the voltage dip.
To mitigate similar issues in the future, Banatwala emphasized the need for a more structured protocol that allows neighboring data centers to disconnect or reconnect in a staggered manner. This change could enable grid operators to devise more effective contingency plans.
Alternatively, there’s potential for reengineering data centers to better withstand such disruptions. ON.Energy has been innovating a new uninterruptible power supply designed for entire data center campuses. Their system integrates batteries and advanced power conversion technology, allowing the grid to perceive a stable load without fluctuations from the various components operating within the data center. This setup enables operators to adjust computing tasks efficiently while minimizing the impact on the grid.
Importantly, this system allows data centers to manage power variations: excess energy can be stored in batteries during peak demand, while surplus can be dispatched immediately if grid supply dips, preventing issues like those experienced during the recent outage.
ON.Energy is currently in the process of installing 3 gigawatts of its systems across four different data center locations, as per de Azevedo’s statement.
Grid operators are becoming increasingly aware of the challenges posed by large power loads such as data centers. For instance, ERCOT is now mandating that these facilities be capable of "riding through" power disruptions.
However, urgency remains. The recent mass disconnection event was double the scale of a previous incident in 2024, where 60 data centers together disconnected, pulling 1.5 gigawatts from the grid. At that time, data centers represented about 6% of PJM's total load, a figure projected to rise to 24% by 2040. Without timely solutions, the implications for grid stability could worsen significantly.
