Our industry needs to provide simple, understandable definitions for commonly used terms such as smart grid, smart cities, distributed energy resources, and microgrids. The simple, understandable definition of resiliency is: The ability to withstand a High Impact, Low Probability (HILP) event with little or no customer outages.
Reliability is measured in minutes. Decades old performance indices like SAIDI, CAIDI, and MAIFI are the standard and, as measured without HILP, the grid is 99.97 percent reliable. But resiliency is measured by total time of line restoration in days.
Many utilities have pilots and programs that enhance resiliency with pole hardening, undergrounding, covered conductors, and a wide array of emerging technologies. Strategic undergrounding in particular has been a popular favorite from Dominion in the east to PG&E in the west.
