NERC Incident Review Examines Data Center Load Loss Challenges

The North American Reliability Corporation (NERC) has issued an incident review highlighting the risks of the growing integration of voltage-sensitive large loads on the power grid due to energy-intensive sources such as data centers and crypto-mining facilities. NERC also issued guidance on integrating voltage-sensitive loads into power systems after investigating a sudden incident that resulted in a 1,500-megawatt load loss caused by a 230 kV transmission line fault.

Historically electric grids have not experienced simultaneous load losses such as the incident in NERC’s review. These types of load losses, especially from data centers, introduce the risk of very high system frequency and voltages as less power flows through the system. Although this particular incident did not result in an extremely high voltage, it still highlights the risk of such incidents in the future and challenges for system operators. Similar incidents have occurred in other interconnection areas cryptocurrency mining loads as well as oil and gas loads.

For the review, NERC consulted with data center owners to examine the causes of load reductions. Since data center loads are sensitive to voltage fluctuations, protections and controls are designed to avoid equipment outages due to voltage disturbances. Data centers often utilize uninterruptible power supply, or UPS, systems that will immediately provide power to the center during a voltage disturbance.

NERC issued guidance to transmission operators and planners to avert major system reliability issues in the future. One of the recommendations from NERC is for system planners to conduct studies to determine the potential magnitude of load loss for system disturbances and see what impact they have on the system. Other highlighted guidance includes actively monitoring to detect load losses coincident with system faults and ensuring that operating agreements with large loads include ramp rates when connecting or reconnecting large loads to the system.

The report also discusses potential future measures NERC could take to avoid incidents from voltage-sensitive loads. These include NERC requiring large loads to be registered identities, modifying its Reliability Standard to include large load interconnection requirements and what assessments transmission planners could use to study the impact of operating large loads.

NERC’s incident review brings attention to one of many potential issues from increasing energy consumption from rapidly growing data centers. Another issue that regulators are looking at is the co-location of large loads to power data centers. In November, the Federal Energy Regulatory Commission rejected an amended interconnection service agreement with PJM Interconnection to increase co-located load capacity at Talen Energy’s Susquehanna nuclear plant to power an Amazon data center. In its order, the agency pointed to possible issues regarding grid reliability and consumer costs.