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

RELIABILITY | ACCOUNTABILITY2 Step Response

RELIABILITY | ACCOUNTABILITY3 No-Step Response

RELIABILITY | ACCOUNTABILITY4 ERCOT Frequency Profile

RELIABILITY | ACCOUNTABILITY5 ±0.036 Hz Vs ±0.016 Hz Deadband

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

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, AZPS 30,135,77131,266,681 61,402, %31.6 DEAA 1,326, %0.7 AVA 11,115,426 12,863,177 23,978, %12.3 BANC 13,183,002 17,356,897 30,539, %15.7 BPAT 113,968,892 54,494, ,463, %86.6 CISO 168,732,241232,339, ,072, %206.1 TPWR 2,914,287 5,005,467 7,919, %4.1 EPE 3,798,187 8,354,189 12,152, %6.2 GRMA 6,170, %3.2 GRID 537, %0.3

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, GRIF 2,092, %1.1 IPCO 15,550,027 17,614,878 33,164, %17.0 IID 1,695,499 4,222,270 5,917, %3.0 LDWP 23,182,322 29,677,274 52,859, %27.2 GWA 775, %0.4 WWA 135, %0.1 NEVP 30,094,050 36,062,507 66,156, %34.0 HGMA 1,648, %0.8 NWMT 11,904,555 10,795,013 22,699, %11.7 PACE 50,474,067 50,590, ,064, %51.9

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, PACW 19,334,101 21,336,826 40,670, %20.9 PGE 10,286,801 20,788,125 31,074, %16.0 PSCO 40,637,992 45,796,153 86,434, %44.4 PNM 14,860,976 15,196,088 30,057, %15.4 CHPD 9,450,355 6,642,935 16,093, %8.3 GCPD 10,153,053 4,097,606 14,250, %7.3 DOPD 4,533,734 1,486,659 6,020, %3.1 PSEI 16,426,621 24,808,520 41,235, %21.2 SRP 35,872,974 28,911,429 64,784, %33.3 SCL 6,526,398 10,035,929 16,562, %8.5

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, TEPC 13,058,015 15,567,738 28,625, %14.7 TIDC 1,851,696 2,605,599 4,457, %2.3 WALC 11,071,766 8,916,472 19,988, %10.3 WACM 37,123,652 24,602,83 61,726, %31.7 WAUW 396, ,877 1,186, %0.6 AESO 75,169,540 77,465, ,635, %78.5 BCHA 61,668,891 61,535, ,204, %63.3 CFE 11,958,741 11,661,353 23,620, %12.1

RELIABILITY | ACCOUNTABILITY11