A recent power outage near Washington, D.C., has exposed a critical vulnerability in how modern electricity grids interact with the surging demand from AI data centres. What should have been a minor grid disruption turned into a significant voltage spike across a vast area, from Northern Virginia to Chicago, due to the near-simultaneous shutdown of multiple data centres.
The incident occurred earlier this week when a single power line failed. Normally, the PJM grid, which serves 67 million customers across 13 US states, would recover within seconds. However, this event saw more than 3 gigawatts of data centre load vanish almost instantly as facilities switched to backup power. This sudden drop in demand created an excess of electricity on the grid, causing voltage levels to spike and lights to flicker across the region, according to data from Ting Labs.
Experts are increasingly concerned that this is not an isolated incident but a 'canary in the coal mine' for future grid stability. Northern Virginia hosts the world's highest concentration of data centres, making it a critical testbed for these issues. Ricardo de Azevedo, CTO at ON.Energy, noted that such events involving large, concentrated loads are becoming more frequent, echoing a similar incident on the PJM grid two years ago.
The fundamental problem lies in the design of many data centres, which are programmed to react to power fluctuations by immediately disconnecting from the main grid and switching to independent backup systems. While this protects the data centre, when numerous facilities do this simultaneously, it creates a massive and sudden drop in demand that the grid struggles to manage, leading to significant imbalances between supply and demand.
Solutions being proposed include developing more sophisticated protocols for data centres to either disconnect or reconnect sequentially, allowing grid operators to manage transitions more smoothly. Another innovative approach involves new uninterruptible power supply (UPS) systems that can absorb grid disruptions, effectively 'hiding' the data centre's fluctuating demand behind a bank of batteries and advanced power conversion equipment. This would present a consistent, stable load to the grid, even as internal operations adjust.