Grid Strength

How "stiff" the grid is in response to small perturbations.

Last Updated:  November 29, 2025

Version:  1.0.0

Generated:  December 04, 2025

Definition by NERC

Source:

Grid strength is a commonly used term to describe how “stiff” the grid is in response to small perturbations such as changes in load or switching of equipment. While strong grids provide a stable reference source for resources, weak grids can pose challenges for connecting new resources and particularly for connecting inverter-based resources. These resources rely on an adequate grid strength (relative to the size of the resource) for synchronizing the power electronics. In addition, inverter-based resources do not provide significant levels of fault current. While these issues alone do not pose a reliability risk, existing control, and protection paradigms need to be adapted to accommodate these changing characteristics from the generation fleet.