City Light has no comments on this section of the BP.

• Pg. 20 - start of 2nd paragraph - Zonal Shapes - Point to Figure 3 & 4. Leave room in BP to update zones.   E.g. Solar on the East side of the cascades is not the same as west side solar.  

QCC values for Variable Energy Resources represent a significant source of uncertainty for utility resource planning. Please make more explicit the frequency with which ELCC studies will be conducted to update QCC values. An updated study each season seems to be implied but is not explicitly stated.

Please make more explicit whether an average or marginal ELCC approach will be used to update QCCs for VERs (i.e. will existing wind/solar be grandfathered in at current ELCCs and new resources receive a QCC based on their marginal contribution or will existing resources receive progressively lower QCCs over time as more wind/solar is added?). Different parts of the BPM seem to suggest different answers.   

The ELCC study section is informative and appreciated from a transparency perspective.  However, it doesn’t describe activities performed by Participants; accordingly, it doesn’t help Participants meet requirements under the WRAP Tariff.  This is an example of content that in the interest of time could have been added in later versions of the business practice.

For resources with only synthesized data where PO decides between that and average, seems like VER always underperforms so using the average should be discounted.
 

a) It appears all VERs are treated as last-in ELCC. How are interactive effects handled? What assumptions are made to reconcile the ELCCs all add up to the load and planning reserve margin established by the advanced assessment? APS contends that this is an important consideration and can be impactful.

b) How are Energy Storage resources treated when performing the ELCC accreditation study work for Solar and Wind? Are they always treated with “preserve reliability” like the ELCC accreditation study for energy storage and during the advanced assessment?

c) What transmission assumptions are included at the time of performing the ELCC study? Is this data collected prior to the ELCC study work consistent with the advanced assessment to establish PRM?

d) Further detail on how future VERs are accredited would be helpful. With each study are average-last in ELCC established so all resources are accredited the same average ELCC or do existing resources get average ELCC and new planned resources get incremental ELCCs?

If these are addressed in another BPM (perhaps 102), it would be helpful to leave a note in this BPM making that reference.  

Similar questions as to interplay/overlap between this BPM and BPM 101 as described above.

SRP encourages the WPP to specifically define the engineering data required by plant operators of wind and solar resources that do not have historcal output and whether participants can provide synthesized output under historical conditions.

Additionally, SRP recommends for the Variable Energy Resource (VER) Effective Load Carrying Capability (ELCC) study process, the Loss of Load Expectation (LOLE) benchmark metric used in the ELCC accreditation study be a one day in 10-year threshold.