1. (a) For each rate year included in an electricity supplier's multi-year rate plan, the commission shall determine, using the most recent service restoration performance report submitted to the commission by the electricity supplier under section 19 of this chapter, a service restoration performance metric for that electricity supplier in the following manner:

   STEP ONE: Determine the electricity supplier's average SAIDI over the course of the five (5) calendar years immediately preceding the most recently concluded calendar year, including major event days, for the electricity supplier's system in Indiana as a whole.

   STEP TWO: Determine the electricity supplier's SAIDI for the most recently concluded calendar year, including major event days, for the electricity supplier's system in Indiana as a whole.

   STEP THREE: Calculate the difference between the STEP ONE result minus the STEP TWO result.

   STEP FOUR: Calculate the quotient of the STEP THREE result divided by the STEP ONE result, rounded to the nearest one-hundredth (0.01).

   STEP FIVE: Calculate the product of one hundred (100) multiplied by the STEP FOUR result. This product is the electricity supplier's service restoration performance metric for the rate year.

2. (b) If the electricity supplier's service restoration performance metric under subsection (a) is a positive number that exceeds five (5), the commission shall adjust the electricity supplier's authorized return for the rate year upward by not more than one-half (0.50) basis point.
3. (c) If the electricity supplier's service restoration performance metric under subsection (a) is a negative number that when multiplied by negative one (-1) exceeds five (5), the commission shall adjust the electricity supplier's authorized return for the rate year downward by not more than one-half (0.50) basis point.

As added by P.L.36-2026, SEC.10.