Tacoma Power supports the proposed modifications to the duration of the Winter Binding Season. The existing Task Force proposal should move forward on its current timeline, allowing continued consideration of additional potential modifications that are suggested in this comment period.
No response submitted.
APS supports the proposal to shorten the Winter Binding Season to November 20 through February 28/29, as well as the formal identification of Peak and Non‑Peak Months. These changes are supported by historical LOLE results and better align capacity obligations with periods of demonstrated reliability risk. APS agrees that periodic review will be important as system conditions, weather patterns, and load characteristics evolve.
SRP understands the goal to refine the Winter Binding Season to better match the time when reliability risks are the highest.
As described in SRP’s response to Item 3, SRP is more concerned with modifying the duration of the Winter Binding Season when this change is combined with the described prescriptive definition of risk carried in shoulder months.
SRP is concerned with the proposed shift from a large share of winter risk into a relatively small number of days, particularly in November.
Seattle supports efforts to align binding season definitions with periods of highest reliability risk. Adjusting the Winter Binding Season to better match modeled loss of load risk is a reasonable step and appears analytically supported.
However, Seattle notes that while winter season boundaries are being refined to better reflect risk, similar attention is needed for the summer shoulder period. In particular, June continues to reflect a high PRM despite being characterized as a non-peak month. From Seattle’s perspectives this suggests that the methodology adjustments have not fully resolved the misalignment between modeled risk and monthly capacity requirements.
Seattle supports refining season definitions but emphasizes that addressing shoulder month PRMs especially June is equally important to ensuring that monthly obligations reflect actual reliability risk across the year.