Will the PO communicate to the entities what percentage Uncertainty Factor was used for each Preschedule day?  For example, if the entire subregion in in an overall deficient condition and the PO determines the subregion is no longer deficient at 8.5%, will entities be told of the 8.5% adder to their load forecast?

Another concern, potentially, is Voluntary Holdback.  Should a surplus entity, become less surplus, following the Uncertainty Factor calculation performed at 03:45 PPT (The Uncertainty Factor to be utilized on the Preschedule Day is performed by the Program Operator 2 hours ahead of the Sharing Calculation run described in BPM 201 Operations Program Timeline.)  Will the entity have time to receive and review with Uncertainty Factor now included in time to make an adjustment to their Voluntary Holdback?

Lastly, will the PO perform any look back analysis to determine the effectiveness of the 10% Uncertainty Factor?  It may be a worthwhile exercise to determine if the 10% is too conservative, or not conservative enough.  Also, looking at how often the 0.5% down adjustments are triggered.  Also, looking at if a subregion gets to the 3% threshold, and if so, how often?

1) Will the uncertainty factor adjustment be utilized in Multi-Day-Ahead Assessment Calculations displayed in WRAP OPS Client? Without the Multi-Day-Ahead Assessment calculation using the adjusted factor - a participant could see a position change because of the adjustment, and no other change to data.

2) The WRAP OPS Client should also visually tell a user that the hour has a uncertainty factor adjustment - and likely how much that adjustment is - That requirement should be documented in PRM.

3) Should the BPM include provisions for if/when/how the uncertaintly factor floor should be evaluated and/or considered for revision?  The 3% value seems to be a best guess at the right limit given what we know today, but with future data it may be worth revisiting.

PacifiCorp understands the uncertainty requirement is intended to fit within the PRM, along with the Contingency Reserve requirement, which is always a minimum of 3% of generation and 3% of load. In a month where 10% uncertainty, 3% of generation, and 3% of load do not fit into within the PRM (for example, July Mid-C PRM of 14.5%), what are the effects? Please elaborate on any operational consequences of this scenario, which is expected to regularly occur.

The 10% uncertainty requirement, while simple, does not reflect the true nature of operational requirements. 10% could be excessive overnight, while insufficient during the net demand peak hours. WEIM participants are currently accustomed to planning around an hourly requirement which is tailored to each entity and provided on a day ahead basis. PacifiCorp understands the Uncertainty WG will revisit the requirement after two or more seasons of operations data has been captured, but is of the opinion the current requirement does not accurately reflect the true needs of the region and will expect it to change. This BPM does not substantiate the 10% requirement with any data. Methods currently exist and are employed to calculate reasonable uncertainty requirements. WPP may consider consultation with such entities when the time comes to revise the 10% requirement.

PacifiCorp would like Participants to be made aware of when the Program Operator is reducing the uncertainty requirement, and the extent to which it has been reduced.

PacifiCorp also needs to better understand what will happen if a reduction of uncertainty to 3% does not cure an aggregate subregion deficiency. Please elaborate further in this BPM.

Additionally, this BPM does not discuss any effects on a Participant’s ability to call upon transmission to fulfill a holdback obligation that is sourcing holdback from a subregion in which the uncertainty requirement has been reduced. Does any uncertainty reduction, even to the minimum of 3%, “block” a Participant’s ability to utilize this transmission?

It should be recognized that the forecast information provided by the Participants will always contains some uncertainty. As such, Powerex recommends the following language, or something similar, be added to section 3:

“In the event of a WRAP Operations Program Energy Delivery Failure, any adjustments made to the Uncertainty Factor will be considered by the Program Administrator as a potential justification for a Delivery Failure Charge Waiver, as outlined in BPM 209.”

The Uncertainty Factor section effectively outlines its role in addressing variances between forecasted and actual loads and resource performance. However, the example in Table 1, while comprehensive for those familiar with the subject, could be enhanced for clarity and broader stakeholder understanding. To make the example more informative, SRP recommends including a narrative to accommodate the example in Table 1 to explain that the reduction of the Uncertainty Factor from 10% to 7.50% for participants 'A' and 'B' helps achieve a balance in the subregion's total capacity, with a total of 0 indicating a match between capacity needs and availability.

Additionally, to ensure stakeholder understanding of the impact of the Uncertainty Factor in the Table 1 example and how the Sharing Calculation Result is derived, it may be helpful to include and/or reference the WRAP Sharing Calculation Formula within the BPM.

Furthermore, clarity on the basis for setting the default Uncertainty Factor at 10% would be beneficial. SRP recommends the WPP include further details or data to provide clarity and justification of how specific percentages were determined. This information may help stakeholders understand the basis and rationale of these values.  

Lastly, SRP recommends that the BPM provide guidance for situations where the Uncertainty Factor is reduced to the minimum threshold of 3%, yet the subregion's total capacity remains in a deficit.

1. How did WPP arrive at 5% of Load + 5% Generation. Was there historical data analysis or Sharing Calculation backtesting done to arrive at this % ?

2. Is the Uncertainty Factor calculated by ~3:20 PT since the BPM 203 states that Program Operator determines the UF 2 hours prior to when the initial sharing calculation is executed using MD file in the Ops program ? Please Confirm

NV Energy appreciates the opportunity to comment on BPM 203 – Program Sharing Calculation Inputs. Section 3 Uncertainty Factor introduces a concept where the uncertainty factor, which accounts for forecast variances for load and resources, would be reduced from 10% to 3% when a subregion is deficient. NV Energy does not support the proposed reduction of the uncertainty factor because this could result in a participant being inaccurately calculated as having surplus when the Megawatts are needed to serve their own load. If a participant is inaccurately calculated as having surplus, then they could be subject to non-delivery penalties. The program should identify surplus to help those that are deficient, however, it would not be beneficial to the program to lower the uncertainty in order to calculate additional subregion surplus when it would be harmful to another participant from meeting their load. Therefore, NV Energy does not support a reduction in the uncertainty factor without a protection included for participants which could include a waiver of any non-delivery penalties when the reduction occurs.

APS believes the BPM is unclear currently whether the Program Operator or Participants can have differing uncertainty values than the sub-region. Is the 0.5% always applied to the full sub-region or can uncertainty values differ among a sub-region by either Participant request to reduce or Program Operator request. APS would also like to understand better how the deficit entities are considered when reducing the uncertainty of the entire sub-region, a reduction in a deficit entities uncertainty component of the sharing calculation would result in them being considered less deficit, is this the intent of the 0.5% reductions, or is the reduction in uncertainty only applicable to surplus entities so that more surplus is available to the same level of deficit?