Today’s LiveWire Spotlight examines FERC Order 881, which adopts key provisions of 2020’s Notice of Proposed Rulemaking (NOPR) to require the universal application of more precise transmission line ratings.  The primary impact will be to Transmission Providers, who will be required to support hourly ambient-adjusted line ratings (AARs) that vary with local air temperature.

FERC Order 881 requires each Transmission Provider to submit a compliance filing within 120 days to revising their OATT to incorporate Attachment M.  The Transmission Provider must fully implement its requirements within three years after the filing.