1.  BPA noted Table 1 is not identified or described in the document - it seems to be added without context. The title describes it as Example Historical Weather Stations, but BPM does not describe what Station#1 or Station #2 means?

Section 5 references a 'Table 3' that doesn’t seem to exist in the documents but may be referencing Table 1, but it identifies 4 weather stations and corresponding back-up weather stations.  If that is supposed to reference Station #1 and #2, the language should be cleaned up to match.

If Station 1 and 2 is not primary and backup, the closeness of stations will serve to throw off averages for the region, as backups they work.

2.  There is only a short description of how the 40 annual load shapes will be created but BPM lacks either detail or examples (or both) of how this will be done. A single paragraph describing the entire process of the load shapes used to establish participant loads and PRMs seems a little on the abbreviated side, especially given that the timing of publication and calculation of these numbers are within participants 2 year exit period. This is insufficient description of how loads are built.

References to Table 3 should be Table 1

The BPM states “a load shape provided by Participants for recent years (e.g. five most recent years) will be combined with historical weather data to synthesize at least forty years of historical weather data” which does not immediately make sense. Should this read so that the recent years actual load is “combined with historical weather data to synthesize at least forty years of load”?

The description of the LOLE study says that the study uses a probabilistic analysis, but fails to describe the process clearly; for example – Five years of recent load data will be combined with 40 years of weather data to synthesize at least 40 years of load data. These 40+ annual load shapes will be an input to a Monte Carlo simulation which samples the load shapes to simulate variability. (This is meant to be an example and not necessarily an accurate description of what the PO actually does).

The BPM states that the PO could decide to update the synthesized load shapes based on “changes in load patterns, sharp increases in load, or changes in climate” . Does a Participant have recourse if they disagree with the PO’s decision to update the synthesized load?

The text in this section refers to "Table 3" however, the BPM shows "Table 1.  Example Historical Weather Stations".  Is this just an error, Table 3 vs. Table 1?

Is it correct to assume the NW region has four primary weather stations, and 4 back-up stations, while the SW has just 5 primary stations?

PNM’s concern is the 5 locations are an average of 690 miles away from our major load pocket.  Comparing Albuquerque’s Average high and low (www.usclimatedata.com) to a cumulated average of the 5 SW weather stations during binding months equates to:

• Winter High +2.55 degrees
• Winter Low +1 degree
• Summer High -1.5 degrees
• Summer Low +3.1 degrees

Should any one of the 5 SW Stations have a data quality issue these averages could be skewed wildly.  As an example, Albuquerque load compared to both Scottsdale and Casper individually saw consistent double-digit variances across most months.

APS seeks additional information and perhaps an example of how the weather and load 40-year synthesized profiles are performed, particularly if there is a check by Participants of profiles that are developed as a sanity check. Also of interest would be the associated impact of using LRZs to create weather and load profiles and whether it masks or does not mask the Program’s ability to see correlation of weather and load effects on the wider footprint than the LRZ (i.e. west wide heat wave)?

It is not specific as to whether Load Data is “raw” data or adjusted for DR events or behind the meter generation, and APS would ask that the BPM reference BPM 101 Advance Assessment in this area as to the details of the Load Data. 

Table 1 (referred in the body as Table 3, needs correction) shows examples of weather station locations.  It lists Scottsdale, Arizona as one location.  Sometimes examples get taken literally, APS suggest changing to Phoenix Arizona, which has much more robust historical weather data in case someone uses the example as a required location. Alternatively, the removal of the SW&E Subregion (or full Table) from the Table could be performed as it appears the Table is only used to illustrate the usage of backup stations.

SRP acknowledges the significance of accurate weather data. SRP prefers that the Sky Harbor Airport be utilized as the primary weather station for the Phoenix metro area. This weather station may better represent regional weather patterns that impact load.