DATE: November 30, 2016 TO: Planning Coordinating ...

1 DATE: November 30, 2016 TO: Planning Coordinating Committee FROM: Underfrequency Load Shedding Review Group SUBJECT: Underfrequency load shedding database maintenance Dear Mr. Brian Keel, This letter is to inform the WECC Planning Coordination Committee that the Under Frequency Load Shedding Review Group (UFLSRG) has completed its 2016 assessment of the UFLS database. Per PRC-006-2 Requirement R6: Each Planning Coordinator shall maintain a UFLS database containing data necessary to model its UFLS program for use in event analyses and assessments of the UFLS program at least once each calendar year, with no more than 15 months between maintenance activities. All WECC UFLS entities were requested to submit their UFLS data via the PRC-006-WECC-CRT-2 Attachment B Reporting Forms.

2 A list of the entities that responded is in Attachment A to this letter. The entities were divided into Generation Owners and Transmission Owners/Distribution Providers. The Attachment B submittals were compared to the data in the master dynamics file (MDF), which is considered the UFLS database. Of the 227 Generator Owner respondents, 60 had data that did not match the MDF. Those entities were contacted and 56 of them resolved their issues. Of the 101 Transmission Owners/Distribution Providers respondents, 35 had data that did not match the MDF. Those entities were contacted and 28 of them resolved their issues. Lastly, a comparison was made of all the frequency protection models in the MDF and what was submitted by the UFLS entities in 2016. The objective was to clean out all the legacy models.

3 If a model existed in the MDF that was not submitted in 2016, it was deemed superfluous. Generator protection models were also checked against the curves in PRC-006-2-Attachment 1 to determine if their inclusion in the MDF was appropriate based on their size and set points. 246 potentially extraneous generator frequency protection models and 1,196 potentially extraneous load shedding models were identified in the MDF. These models are currently being evaluated to determine if they should be deleted from the MDF. Thank you, Nicholas Shipman Chris Pink, Power System Planning Engineer Chair, UFLSRG Tri-State Generation & Transmission Association Tri-State Generation & Transmission Association I-2 Attachment A Generation Owner Responders AES Alamitos LLC AES Huntington Beach AES Redondo Beach LLC Algonquin Power Sanger Alta Wind VIII, LLC AltaGas Brush Energy Inc.

4 AltaGas Ripon Energy Inc. AltaGas San Joaquin Energy Inc. APEX - Los Angeles Department of Water and Power Aragonne Wind LLC Arizona Electric Power Cooperative Arizona Public Service Arlington Valley Arlington Valley Solar Energy II, LLC ASI Operations Inc Avangrid Renewables Avista Basin Electric Power Cooperative BIV Generation company LLC Black Hills Corporation Blythe Energy Center Boise Kuna Irrigation District Bureau of Reclamation Burney Forest Power (NAES Corporation) Caithness Shepherds Flat, LLC California Department of Water Resources Calpeak Power - Panoche, LLC CalPeak Power - Vaca Dixon, LLC Catalina Solar, LLC Cedar Creek II, LLC Cedar Creek Wind Energy LLC Cedar Point Wind, LLC Centinela Solar Energy, LLC City of Farmington Electric Utility System City of Idaho Falls Electric Light Division City of Redding City of Spokane Waste-To-Energy Facility City of St.

5 George Clark Public Utilities Colorado Green Holdings, LLC Colorado Highlands Wind, LLC Colorado Power Partners Colorado Springs Utilities Colstrip Energy Limited Partnership Columbia Basin Hydropower Coolidge Power LLC - NCR11094 Copper Mountain Solar 2, LLC Copper Mountain Solar 3, LLC Coso Energy Developers Coso Finance Pertners Coso Power Developers Crockett Cogeneration Deseret Generation & Transmission Douglas County PUD El Paso Electric company Elk Hills Power, LLC Energia Sierra Juarez, S. de de Energy Keepers Incorporated Energy Northwest - Columbia Energy Northwest - Energy/Business Services Equilon Enterprises, LLC Eugene Water & Electric Board Exelon Generation Co. LLC Frederickson Power, LP Gila Bend Operations company Goshen Phase II LLC Grays Harbor Energy LLC Griffith Energy, LLC Harbor Cogen, LLC Harbor Cogeneration company , LLC Hatchet Ridge Wind LLC Hermiston Generating company , Hetch Hetchy Water and Power HGMA-New Harquahala Generating Facility, LLC High Desert Power Project, LLC I-3 Idaho Power company Idaho Wind Partners 1, LLC Imperial Irrigation District Imperial Valley Solar 1, LLC Indigo Generation, LLC Inland Empire Energy Center, LLC Judith Gap Energy LLC Kern River Cogeneration company KES Kingsburg, Kings River Convservation District La Paloma Generating company LLC Larkspur Energy, LLC Lewis County PUD No.

6 1 Los Angeles Department of Water and Power Malacha Hydro Limited Partnership GOP Malaga Power, LLC ManCheif Power company , LLC Mariposa Energy, LLC Meadow Creek Project company LLC Merced Irrigation District Mesquite Solar 1, LLC Mid-Set Cogeneration company Midway Peaking, LLC Midway Sunset Cogeneration company Milford Wind Corridor Phase I, LLC Modesto Irrigation District Mojave 16/17/18, LLC Mountain Air Projects MPL (name is blank) Mt, Poso Cogeneration company Mustang Hills, LLC NAES Corporation - Harvest Wind Project NAES Corporation - White Creek Wind 1 Naniwa Energy LLC NaturEner Power Watch, LLC NaturEner Rim Rock Energy, LLC Nevada Cogeneration Assoociates #1 Nevada Irrigation District Nevada Power company Nevada Solare One, LLC Newmont NextEra Energy Resources Northern California Power Agency NorthWestern Energy NRG Energy, Inc.

7 NRG Energy, Inc. (AGCS) NRG Energy, Inc. (CPI) NRG Energy, Inc. (ELSP) NRG Energy, Inc. (EMMT) NRG Energy, Inc. (Etiwanda, Walnut Creek) NRG Energy, Inc. (HPRII) NRG Energy, Inc. (IVAN) NRG Energy, Inc. (Mandalay, Ormond Beach) NRG Energy, Inc. (Marsh Landing, Pittsburg) NRG Energy, Inc. (NRGW) NRG Energy, Inc. (SNRS) NRG Energy, Inc. (SPC) Ocotillo Express Wind LLC Orange Grove Energy, ORNI 39 ORNI 47 Otay Mesa Energy Center Pacific Gas and Electric company Pacific Ultrapower Chinese Station Pacific Wind, LLC PacifiCorp Palouse Wind, LLC Panoche Energy Center LLC Pend Oreille County Public Utility District #1 Pinyon Pines Wind I, LLC Pinyon Pines Wind II, LLC Placer County Water Agency Plains End I, LLC Plains End II, LLC Platte River Power Authority Portland General Electric ProEnergy Services Public Service Co of New Mexico Public Service of Colorado Public Utility District No.

8 1 of Chelan County Public Utility District No. 1 of Cowlitz County, WA Public Utility District No. 2 of Grant County, WA Public Utility District of Snohomish County Puget Sound Energy Rathdrum Power, LLC Red Horse Wind 2, LLC Rio Bravo Fresno Rio Bravo Rocklin Rockland Wind Farm, LLC Rocky Mountain Power, LLC Russell City Energy company , LLC Sacramento Municipal Utility District I-4 Salt River Project San Diego Gas & Electric San Diego Gas & Electric San Diego Gas & Electric Seattle City Light Sentinel Energy Center, LLC Shiloh IIII Wind Project, LLC Shiloh IV Wind Project, LLC Shiloh Wind Project 2, LLC Sierra Pacific Industries Sierra Pacific Power dba NV Energy Silicon Valley Power Solar Star California XIII, LLC Solar Star California XIX, LLC Solar Star California XX, LLC South Feather Power Project Southern California Edison company SPI Anderson 2 Spindle Hill Energy LLC Spring Canyon Energy LLC Spring Valley Wind LLC Sunnyside Cogeneration Associates SWG Colorado, LLC SWG Fountain Valley Power, LLC Sycamore Cogeneration company Tacoma Power Talen Montana, LLC Tenaska, Inc.

9 Tenaska, Inc. Termoelectrica de Mexicali, S. de de Terra-Gen Dixie Valley, LLC Thermal Energy Development Partnership Three Buttes Windpower LLC Tonopah Solar Energy LLC Top of the World Wind Energy Topaz Solar Farms LLC - NCR 11342 TransAlta Centralia Generation TransAlta Wyoming Wind LLC Tri-Dam Project/South San Jaquin and Oakdale Irrigation Districts Tri-State Generation and Transmission Association, Inc. Turlock Irrigation District Tuscon Electric Power company US Army Corps of Engineers - Seattle District US Army Corps of Engineers - Walla Walla District USACE - Portland District USACE-Omaha Utah Associated Municiple Power Systems Utah Red Hills Renewable Park, LLC Valencia Power, LLC Vantage Wind Energy LLC Watson Cogeneration company Wellhead Power Panoche LLC West Valley Power LLC Western Power and Steam, Inc WestRock CP, LLC Williams Flexible Generation, LLC Windstar Energy, LLC Windy Flats Partners, LLC Woodland BiomassPower.

10 Ltd Yuba County Water Agency I-5 Transmission Owner Responders Alameda Municipal Power Arizona Electric Power Cooperative Arizona Public Service Avista Basin Electric Power Cooperative Benton County PUD Black Hills Corporation Bonneville Power Administration Bureau of Reclamation California Department of Water Reources California ISO City of Anaheim City of Burbank Water and Power City of Forest Grove City of Fort Collins City of Gallup City of Glendale City of Idaho Falls Electric Light Division City of Loveland City of Palo Alto City of Pasadena Water and Power City of Redding City of Riverside Public Utilities City of Roseville City of St. George Clark Public Utilities Colorado Springs Utilities Columbia River People Utility District Deseret Generation and Transmission Douglas County PUD El Paso Electric Empire Electric Association Eugene Water and Electric Board Fall River Rural Electric Flathead Electric Cooperative Glacier Electric Cooperative Grant County PUD Hetch Hetchy Water and Power Holy Cross Energy Idaho Power company Imperial Irrigation District Intermountain Rural Electric Assoc Klickitat County PUD La Plata Electric Association Inc.