NERC Proposes New Rules for Data Center Grid
NERC is creating a new class of registered entity and reliability standards for large computational loads like data centers, aiming to close gaps exposed
A 2024 grid disturbance revealed a critical vulnerability when data center loads disconnected en masse. The North American Electric Reliability Corp. (NERC) is now pushing a three-part action plan to overhaul how large, fast-growing loads connect to and behave on the transmission system.
At about 7 p.m. On July 10, 2024, a lightning arrester failed on a 230-kV line. Protection systems cleared the fault, causing six brief voltage depressions over 82 seconds. During these sags, approximately 1,500 megawatts of demand vanished from the system. NERC documented that this was all data center-type load disconnecting due to its own protection settings, not utility action. The load was not even on the faulted line. Frequency rose to 60.047 Hz before stabilizing, and voltage swelled to 1.07 per unit, requiring operator intervention. This incident has become a key case study.
The bulk power system is extensively planned for the loss of large generators. It has far less experience with the synchronized loss of hundreds or thousands of megawatts of load. NERC's 2025 Long-Term Reliability Assessment expects North American summer peak demand to grow by about 224 gigawatts over the next decade, with new data centers for artificial intelligence accounting for most of the increase. These facilities can reach gigawatt-scale, comparable to a large power plant, and can be built in one to two years-far faster than the transmission needed to serve them.
A Process Built for Generators, Applied to Loads
NERC's Large Loads Working Group concluded in a March 2026 assessment that existing reliability standards and interconnection practices are inadequate for emerging large loads. While standards FAC-001 and FAC-002 govern the interconnection process, large-load interconnection lacks a settled, uniform framework. Requirements vary by utility, as the process usually follows state-jurisdictional tariffs. There is no standard commissioning test for facility behavior and no uniform obligation to maintain accurate dynamic models after interconnection.
A core problem is a lack of coordination. Utility transmission owners set relay and reclosing schemes. Facility owners program ride-through logic in their uninterruptible power supply systems and drives. Historically, neither side shared these settings. A fault cleared correctly by the utility can still trip load offline because the facility's protection reads the voltage sag as a threat. Some sites use counting logic, disconnecting after a set number of sags and staying offline until manually reconnected. In the July 2024 event, about 1,260 MW dropped out at the third reclose and did not return for hours.
Most large loads are not NERC-registered entities, meaning they are not directly obligated to provide planners with accurate dynamic models or performance data. NERC states that details needed for studies may not exist until late in development, and operators may guard information as commercially sensitive. The result is models that do not match reality.
Rebuilding the Rulebook
NERC's action plan is moving on an accelerated timeline. The centerpiece is the creation of a new class of registered entity called the computational load entity (CLE). Proposed criteria from April 2026 would capture facilities with at least 20 MW of aggregate connected load, connected at a single point to the bulk power system at 60 kV or above, and hosting at least 1 MW of computational load. This registration would bring qualifying facilities directly under mandatory reliability standards. NERC is working to file the criteria by the end of 2026.
Running alongside is standards development under Project 2026-02, launched in March 2026. The work aims to develop requirements for computational loads, focusing on better dynamic models, model maintenance, commissioning, validation, and operational coordination. NERC has indicated that some broader requirements, like industry-wide minimum ride-through thresholds, may fall outside the initial 2026 package.
The third piece is immediate, voluntary guidance. NERC's May 2026 reliability guideline, Risk Mitigation for Emerging Large Loads, offers strategies for transmission planners and operators to manage risks with existing large loads before new standards take effect.
