1. Frequency Response WECC Frequency Response Obligations Robert W. Cummings NERC Director of Reliability Initiatives and System Analysis WECC Operating Committee Meeting March 26, 2015

2. RELIABILITY | ACCOUNTABILITY2 Step Response

3. RELIABILITY | ACCOUNTABILITY3 No-Step Response

4. RELIABILITY | ACCOUNTABILITY4 ERCOT Frequency Profile

5. RELIABILITY | ACCOUNTABILITY5 ±0.036 Hz Vs ±0.016 Hz Deadband

6. RELIABILITY | ACCOUNTABILITY6 June 1 – Begin analysis of events  Gather and analyze 1-second and sub-second data for all BAL-003 and ALR 1-12 frequency events July FWG/RS Meeting – present IFRO calculation results and August 1 – Begin analysis of FERC For 714 NEL and generation data Mid-August – FWG & RS acceptance by conference call vote September OC meeting – Present for approval October 1 – File FRAA report with FERC November 1 – Disseminate BA FROs FR Annual Analysis and FRO Schedule

7. RELIABILITY | ACCOUNTABILITY7 BA Frequency Response Obligations BA Gen MWH NEL MWH Total MWH % of WECC BA FROs MW / 0.1 Hz WECC869,816,038892,888,866 1,762,704,904100906 AZPS 30,135,77131,266,681 61,402,4523.483%31.6 DEAA 1,326,5930 0.075%0.7 AVA 11,115,426 12,863,177 23,978,6031.360%12.3 BANC 13,183,002 17,356,897 30,539,8991.733%15.7 BPAT 113,968,892 54,494,712 168,463,6049.557%86.6 CISO 168,732,241232,339,960 401,072,20122.753%206.1 TPWR 2,914,287 5,005,467 7,919,7540.449%4.1 EPE 3,798,187 8,354,189 12,152,3760.689%6.2 GRMA 6,170,4110 0.350%3.2 GRID 537,2570 0.030%0.3

8. RELIABILITY | ACCOUNTABILITY8 BA Frequency Response Obligations (cont.) BA Gen MWH NEL MWH Total MWH % of WECC BA FROs MW / 0.1 Hz WECC869,816,038892,888,866 1,762,704,904100906 GRIF 2,092,7430 0.119%1.1 IPCO 15,550,027 17,614,878 33,164,9051.881%17.0 IID 1,695,499 4,222,270 5,917,7690.336%3.0 LDWP 23,182,322 29,677,274 52,859,5962.999%27.2 GWA 775,5300 0.044%0.4 WWA 135,5700 0.008%0.1 NEVP 30,094,050 36,062,507 66,156,5573.753%34.0 HGMA 1,648,1570 0.094%0.8 NWMT 11,904,555 10,795,013 22,699,5681.288%11.7 PACE 50,474,067 50,590,830 101,064,8975.734%51.9

9. RELIABILITY | ACCOUNTABILITY9 BA Frequency Response Obligations (cont.) BA Gen MWH NEL MWH Total MWH % of WECC BA FROs MW / 0.1 Hz WECC869,816,038892,888,866 1,762,704,904100906 PACW 19,334,101 21,336,826 40,670,9272.307%20.9 PGE 10,286,801 20,788,125 31,074,9261.763%16.0 PSCO 40,637,992 45,796,153 86,434,1454.903%44.4 PNM 14,860,976 15,196,088 30,057,0641.705%15.4 CHPD 9,450,355 6,642,935 16,093,2900.913%8.3 GCPD 10,153,053 4,097,606 14,250,6590.808%7.3 DOPD 4,533,734 1,486,659 6,020,3930.342%3.1 PSEI 16,426,621 24,808,520 41,235,1412.339%21.2 SRP 35,872,974 28,911,429 64,784,4033.675%33.3 SCL 6,526,398 10,035,929 16,562,3270.940%8.5

10. RELIABILITY | ACCOUNTABILITY10 BA Frequency Response Obligations (cont.) BA Gen MWH NEL MWH Total MWH % of WECC BA FROs MW / 0.1 Hz WECC869,816,038892,888,866 1,762,704,904100906 TEPC 13,058,015 15,567,738 28,625,7531.624%14.7 TIDC 1,851,696 2,605,599 4,457,2950.253%2.3 WALC 11,071,766 8,916,472 19,988,2381.134%10.3 WACM 37,123,652 24,602,83 61,726,4833.502%31.7 WAUW 396,145 789,877 1,186,0220.067%0.6 AESO 75,169,540 77,465,640 152,635,1808.659%78.5 BCHA 61,668,891 61,535,231 123,204,1226.989%63.3 CFE 11,958,741 11,661,353 23,620,0941.340%12.1

11. RELIABILITY | ACCOUNTABILITY11