APPENDIX H: Pacific Northwest California Transfer Increase Informational Special Study

Transcription

1 APPENDIX H: Pacific Nrthwest Califrnia Transfer Increase Infrmatinal Special Study Califrnia ISO/MID H-1

2 Intentinally left blank Califrnia ISO/MID H-2

3 Table f Cntents 1 Intrductin Objective Study Assumptins and Criteria LADWP Studies n PDCI Rating Upgrade Increase the Capacity f AC and DC Interties Near-term Assessment (Year 2023) Near-term Assessment 5,100 MW Nrth t Suth Flw n COI Near-term Assessment Suth t Nrth Flw n PDCI and COI Lng-term Assessment (Year 2028) PNW Hydr Mdel in Prductin Cst Mdel (PCM) Analysis f Lng-term Assessment Results Summary f Lnger-term Assessment Results 26 5 Increase Dynamic Transfer Capability (DTC) Excessive vltage fluctuatins and reactive switching RAS Arming Vltage Stability Ptential Slutins T Increase DTC Implementing sub-hurly scheduling n PDCI Assigning Resurce Adequacy (RA) Value t firm zer-carbn imprts ISO s RA prcurement prcess Histrical MIC allcatin n the Malin 500 Branch Grup Histrical RA shwings n the Malin 500 Branch Grup Histrical MIC allcatin n NOB Branch Grup (PDCI) Histrical RA shwings n NOB Branch Grup (PDCI) COI and PDCI Flws in Real Time Ptential barriers fr higher RA shwings Summary f RA Analysis Summary and Cnclusins Next Steps Attachments Attachment 1 BPA DTC Radmap Califrnia ISO/MID H-3

4 1 Intrductin On February 15, 2018, the ISO received a request frm Rbert B. Weisenmiller, Chair f the CEC and Michael Picker, President f the CPUC1, that the ISO undertake a transmissin sensitivity study within the transmissin planning prcess fcused n increasing capabilities fr transfers f carbn-free electricity between the Pacific Nrthwest and Califrnia. Expanded transmissin capability, and increasing the transfer f lw-carbn supplies t and frm the Nrthwest in particular, was seen t be ne f the multiple puzzle pieces that the agencies must examine t build a cumulative phase ut strategy f Alis Canyn usage and address ptential impacts n the gas-fired generatin fleet. The request prvided the fllwing synpsis fr the sensitivity study: Increasing rated capacity f AC Intertie and Pacific DC Intertie. Explre the csts and benefits f ptential increases t AC and DC intertie capacity with the Pacific Nrthwest (PNW), cnsidering a range f ptins as well as assessing dwnstream impacts t transmissin within Califrnia. Increasing dynamic transfer capability limits beynd 400 MW. Cnduct engineering analyses t determine an upper limit n dynamic transfer capability frm the BPA system. Reflect BPA Reliability Actin Scheme (RAS) autmatin effrts and the relatinships t vltage variability and stability cncerns within bth the BPA system and the brader Nrthwest grid. Autmating manual cntrls n key BPA infrastructure. Assume that within a five-year hrizn BPA (at Cellil) and peratrs at Sylmar deply necessary upgrades t the autmatic generatin cntrl and Energy Management Systems (EMS) perating at the cnverter statins t facilitate intra-hur scheduling n the Pacific DC Intertie and perfrm sensitivity analyses t assess the impacts t Nrthwest hydr energy transfer capability frm a reliability and ramping perspective t supprt the gal f clsing Alis Canyn. Assigning sme RA value t firm zer-carbn imprts r transfers. Develp a bunding case that assumes maximal utilizatin f existing infrastructure investments supprting Energy Imbalance Market peratins f participating entities in the Nrthwest, as well as the integratin f synchr-phasr data int cntrl rm peratins. This case will infrm further study and explre the maximum annual expected Nrthwest hydr imprt capability f the Califrnia ISO grid t estimate an upper bund n avided GHG emissins assuming that RA/RPS cunting criteria are nt limiting. These studies fcused n evaluating key ptins t increase transfer ratings f the AC and DC interties with the Pacific Nrthwest, and assessing what rle these systems can play in displacing generatin whse reliability is tied t Alis Canyn. The expectatin was that the insights gained frm this sensitivity study can be used t infrm a brader assessment f Alisn Canyn Phase-Out ptins, cnsistent with the directin the state 1 Califrnia ISO/MID H-4

5 agencies have received t develp plans that wuld allw fr the shutdwn f the Alis Canyn Natural Gas Strage Facility. The ISO has cllabratively wrked with the Califrnia Energy Cmmissin (CEC), the Califrnia Public Utilities Cmmissin (CPUC), Bnneville Pwer Administratin (BPA), Ls Angeles Department f Water and Pwer (LADWP), and Suthern Califrnia Edisn (SCE) t develp this study scpe. In additin, a high-level review f study bjectives and f the scpe was prvided t ther wners and peratrs f the path t ensure alignment n all aspects f this infrmatinal special study and will d as required thrughut study. These wners and peratrs included PG&E, TANC, WAPA, PacifiCrp, PGE, the City f Glendale, the City f Burbank, the City f Pasadena, and BANC. The intent f this dcument is t articulate clearly the bjective f the study, the assumptins and study methdlgy, rles and respnsibility f different entities in the study and deliverables. 2 Objective The bjective f this study was t explre the fllwing fur aspects f hw t increase the pwer transfer capability between Pacific Nrthwest and Califrnia taking int accunt planning, peratin, and market cnsideratins. Increase the Capacity f AC and DC Interties Increase Dynamic Transfer Capability Cntrl Autmatin (Sub-hurly scheduling n PDCI) Assigning RA Value t Imprts Fr each f the abve study items, the existing limitatins wuld be reviewed and dcumented fllwed by identifying incremental system enhancements that wuld be required t address the limitatin and increase the transfer capability. The study wuld identify pssible increase in transfer capability in near term and lng term. The near term study wuld fcus n hw t increase the transfer capability by utilizing the existing infrastructure under favrable cnditins and withut significant system reinfrcements. The lnger-term study wuld evaluate availability f hydr resurces in PNW in the lng term and hw much additinal transfer capability wuld be required t fully utilize the hydr resurce. This sensitivity study was dne mainly fr infrmatinal purpses. Therefre, it was nt expected that any transmissin prject t be apprved as part f this study. Hwever, minr upgrades culd be cnsidered fr apprval, especially if they are beneficial in baseline studies, by being referred t the ISO s ecnmic study prcess. Califrnia ISO/MID H-5

6 3 Study Assumptins and Criteria Details f the study assumptins, methdlgy, and criteria are prvided in the Study Plan 2. A key parameter in these studies is the categrizatin f the cntingency f tw adjacent circuits nt n the same twer, which varies between different standards: The WECC Reginal Criteria used t treat adjacent 500 kv lines (250 feet separatin r less) as a P7 cntingency The WECC Path Rating prcess currently treats the cntingency as a P7 The NERC TPL standard cnsiders the N-2 f adjacent circuits nt n same twer as an Extreme Event (regardless f separatin), and the N-1-1 is cnsidered a P6 cntingency CAISO peratins treats the N-2 cntingency n COI lines in the same right-f-way but n separate twers (that have less than 250 feet separatin) as a cnditinally credible cntingency. Operatins treats these cntingencies t be credible, and set perating limits accrdingly nly, when there is a risk such as fire r severe weather cnditins in the area f the lines. WECC is currently reviewing its Path Rating prcess with regards t the cntingency lss f adjacent circuit. 3 In this study, the rating f the transmissin paths were calculated fr bth the P6 and P7 treatment f the N-2 cntingencies. 3.1 LADWP Studies n PDCI Rating Upgrade As discussed in the Study Plan, the WECC path rating f the PDCI is 3220 MW in the nrth t suth and 3100 MW in the suth t nrth directin. LADWP limits the flw in real time peratin t 3210 MW in the nrth t suth and 1,000 MW in the suth t nrth directin. LADWP is cmmencing a third party cnsultant study t cnduct an engineering and planning study t identify the system upgrades, mdificatins, utage cnstraints required t increase the PDCI transfer capability frm 3220 MW t 3800 MW. Intermediate upgrades shall als be cnsidered where apprpriate, t imprve transfer capacity beynd 3220 MW while minimizing the capital investment and utage times. The impact f these upgrades n the feasibility f reusing the existing twers and cnductrs will als be evaluated. The study will include the cst assciated with all upgrades/mdificatins identified in the analysis, the utage time and cnstraints required t perfrm the upgrade wrk, and the intermediate &DefaultItemOpen=1 t&defaultitemopen=1 emopen=1 Califrnia ISO/MID H-6

7 system impacts during prject implementatin and cnstructin stages. Belw is mre detailed infrmatin that will be cvered as part f the study. Engineering and Planning Study Perfrmance f a system impact study (SIS) which includes: Study plan and list f assumptins, criteria and cntingencies that will be used t cmply with the NERC Reliability Standards. Steady state lad flw analysis, shrt circuit analysis, and dynamic studies fr system stability cnsideratins needed t identify impacts n LADWP AC system at Sylmar AC switchyard and beynd as a result f the increase f HVDC capacity. The scenaris cvered in study include but are nt limited t vltage upgrade, current upgrade r a cmbinatin f bth amng all viable ptins. Analysis f inadvertent flws in the LADWP system and mitigatin measures Sylmar Cnverter Statin and PDCI Analysis The assessment shall include an engineering analysis t identify upgrades needed t reach reliable peratins at 3800 MW: Upgrades required at Sylmar Cnverter Statin (Suthern terminus f the PDCI) including but nt limited t: Cnverter Valves Cnverter Transfrmers Cntrls and prtectin system AC & DC filters Electrde system Cling Telecmmunicatin Civil and seismic upgrades All ther necessary and assciated cmpnents An analysis f the 581 mile HVDC transmissin line between the Nevada-Oregn Brder (NOB) and Sylmar Cnverter Statin identifying all upgrades required fr peratin at a higher vltage r current t achieve an increased transfer capability, up t a maximum f 3800 MW. The analysis shall include, but nt limited t, a review f the fllwing: Insulatin Clearances and line sag Califrnia ISO/MID H-7

8 Cnductr surface gradient and the resulting audible and radi nise Electric field strength at grund level Thermal rating f cnductrs Lidar survey f biple circuit and electrde Evaluatin f reusing existing twers and cnductrs Any ther limiting factrs that wuld necessitate an infrastructure upgrade LADWP is cnducting these studies with full participatin and cperatin f PDCI Suthern participants including SCE and the Cities f Glendale, Burbank, and Pasadena. The studies are expected t be cmpleted by the end f Q3, Since the LADWP studies were nt cmplete when this infrmatinal was perfrmed, the current WECC and peratinal ratings f PDCI were used in this infrmatinal studies. 4 Increase the Capacity f AC and DC Interties The Pacific Nrthwest (PNW) system cvers the fur US states f Washingtn, Oregn, Idah and Mntana. The system has 35,000 MW f installed hydr generatin capacity with varying levels f energy and flexibility available in different seasns. The characteristics f lad and generatin resurces in PNW and Califrnia prvide an pprtunity t exchange pwer between the tw systems in a way that maximizes the utilizatin f the generatin and transmissin assets and minimize the ttal GHG emissins by electricity generatin. There are tw main intercnnectins between PNW and Califrnia pwer systems; Califrnia Oregn Intertie (COI) and Pacific DC Intertie (PDCI). Based n the WECC path rating catalgue, the ttal transfer capacity f these paths are currently 8,020 MW in the nrth t suth directin and 6,775 MW in the suth t nrth directin. Figure shws the schematic diagram f these WECC path and majr 500 kv lines in the area. Benefits f increasing the capacity f AC and DC interties t increase the exchange f carbn-free electricity between PNW and Califrnia was explred in this study. This study was dne fr tw time hrizns; near term (year 2023) and lng term (year 2028). Califrnia ISO/MID H-8

9 Figure 3.1-1: Schematic Diagram f AC and DC Interties between PNW and Califrnia Big Eddy Jhn Day Slatt Cellil Marin Buckley Grizzly Path 65 (PDCI) Klamath Falls Redmnd Lad Hemingway Summer Lake Captain Jack Malin Path 76 Path 66 (COI) Rund Muntain Olinda Table Muntain Maxwell Tracy Vaca Dixn t Sylmar t Ls Bans Tesla Legend: 500 kv Series Capacitr 4.2 Near-term Assessment (Year 2023) The fcus f the near-term analysis was t assess the ptential t maximize the utilizatin f the existing transmissin system in bth nrth t suth (N-S) and suth t nrth (S-N) flw directins and identify minr upgrades that may be required t increase the capacity. Likely cnditins fr high levels f pwer exchange between PNW and Califrnia were studied under tw scenaris: Energy Transfer The assumptin in this scenari is that sustained surplus energy is available in ne system while demand exists in the ther system. An example f a nrth t suth energy transfer scenari culd be early evenings in summer in which high temperatures and a lack f slar generatin create high demand in Califrnia that culd be served by surplus hydr generatin in the nrthwest. A ptential scenari fr the energy transfer in the suth t nrth directin is the late afternn in the Califrnia ISO/MID H-9

10 fall in which there is surplus slar generatin in Califrnia due t mild temperature that culd be transferred t serve lad in the nrthwest. Resurce Shaping Maximum slar curtailment in Califrnia ccurs in the middle f the day in early spring (March and April). The reasn fr slar curtailment is the significant amunts f slar generatin while the lad is relatively lw (arund 60% f the peak lad). Anther characteristic f Califrnia lad in early spring is the high ramp rate in the late afternn as slar generatin, which is a significant prtin f the supply at the time, quickly drps t almst zer in the space f a few hurs. The basis fr resurce shaping scenari in the spring is t exprt the surplus generatin in Califrnia t the PNW in the middle f the day (S-N flw) and imprt energy in late afternn and early evening hurs t help with the steep ramp (N-S flw). The assumptin in this scenari is t utilize strage capability f PNW hydr generatin t shape the slar generatin in Califrnia t reduce curtailment f slar utput Near-term Assessment 5,100 MW Nrth t Suth Flw n COI Tw study cases were develped fr this assessment; Energy Transfer and Resurce Shaping: Energy Transfer (N-S): COI = 5,100 MW N-S, PDCI = 3,210 MW N-S, ther paths based n histrical data; Late afternn, early evening hurs in ht summer days in Califrnia in which it is expected that the Califrnia lad is clse t its net-peak lad; Califrnia slar generatin is clse t zer; and, Plant utages in the desert Suthwest. Resurce Shaping (N-S): COI = 5,100 MW N-S, PDCI = 3,210 MW N-S, ther paths based n histrical data; Late afternn, early evening hurs in early spring in which highest Califrnia demand ramp rate is expected due t drp in slar generatin; Califrnia slar generatin is clse t zer; and, Califrnia lad is arund 60% f its peak lad. The fllwing table shws a summary f the base cases fr these tw study scenaris: Califrnia ISO/MID H-10

11 Table 4.2-1: Parameters f the COI = 5,100 MW N-S study scenaris Nrthern Califrnia Hydr Generatin Assumptins T test system perfrmance under stressed scenaris, nrthern Califrnia hydr generatin is typically dispatched at 80% f their capacity. Hwever in this special study, the bjective was t test the system under favrable cnditins rather than a stressed scenari. A review f nrthern Califrnia Hydr utput in the last 5 years was perfrmed in late afternn/early evening hurs in summer and spring. The median values f nrthern Califrnia hydr generatin as a percentage f installed capacity are shwn in Figure Based n this analysis, nrthern Califrnia hydr generatin was assumed t be arund 60% and 40% fr summer and spring study cases respectively. Califrnia ISO/MID H-11

12 Figure 4.2-1: Median f Histrical Nrthern Califrnia Hydr Generatin in the Study Hurs Analysis f COI = 5,100 MW N-S Energy Transfer Case (Summer) One imprtant check in setting up study cases with high COI flws is the COI pick-up fllwing the trip f ne Pal Verde unit. Histrically, fllwing the trip f ne Pal Verde unit, 42% - 45% f its generatin shws up n COI and base cases are typically set up in the studies t reflect that. Hwever, in this study, the COI pick-up is arund 38% f ne Pal Verde unit. The reasn is that hydr generatin in the PNW is high and, as a result, the generatrs dn t have large amunts f headrm t respnd t generatin tripping. Nte that in additin t the COI flw f 5,100 MW, PDCI is dispatched at 3,210 MW. High exprt alng with relatively high lad in the NW (summer evening) requires high hydr utput. As COI flw increases beynd a certain threshld, the RAS t drp generatin in the PNW system is armed t address reliability issues fr the simultaneus (P7) utage f tw adjacent 500 kv lines. At maximum COI flw f 4,800 MW, arund 2,400 MW generatin in PNW is armed fr the RAS. If the cntingency categrizatin remains P7 and the RAS arming amunt desn t change, the maximum COI flw limit will remain 4,800 MW. One apprach t increase the COI capacity is t treat the simultaneus utage f tw adjacent circuits as cnditinally credible, in which the utage is cnsidered a P6 (N-1-1) cntingency unless certain high risk weather r fire cnditins exist that makes them a credible P7 cntingency. This study shwed that with this apprach, COI flw culd be increased t 5,100 MW befre any criteria vilatins ccur. At 5,100 MW COI flw, the N-1 utage f the Rund Muntain Table Muntain 500 kv line laded the remaining line at 100%. Therefre, under favrable cnditins, COI flw culd be set at 5,100 MW. Study results shw that with COI flw at 5,100 MW, a simultaneus utage f Malin Rund Muntain #1 and #2 500 kv lines, caused a 10% verlad n the Captain Jack Olinda 500 kv line. Nte that if COI is at 5,100 MW n this basis, this duble utage wuld be cnsidered nt t be credible and therefre is equivalent f an Extreme Event fr which planning slutins are nt required by NERC r WECC standards. Califrnia ISO/MID H-12

13 Anther apprach t increase COI t 5,100 MW is t increase generatin tripping in the PNW r include lad shedding in Califrnia fllwing the N-2 cntingency. BPA has indicated that increasing generatin tripping in the PNW culd be challenging. Currently there are number f lad shedding schemes in service in Califrnia t address reliability issues. By adding lad shedding t the COI RAS, it wuld be pssible t increase COI t 5,100 MW t address thermal verlads fllwing N-2 cntingencies. Details f the lad shedding scheme such as magnitude and lcatin shuld be defined in future studies. N vltage issue and vltage r dynamic stability criteria vilatins were identified fr the energy transfer case. Studies Cnducted by BPA n PNW System Figure shws a schematic diagram f the BPA system cnnecting t Califrnia. Study results shwed that in determining the ttal NW net exprt, the critical cnditin is the duble utage f the Jhn Day Grizzly #1 and Buckley Grizzly 500 kv lines verlading the Jhn Day Grizzly #2 500 kv line. There are number f factrs impacting the maximum COI flw: Path 75 (Hemingway Summer Lake) flw P76 (Alturas Prject) flw Redmd Imprt Klamath Falls generatin The rating f the Jhn Day Grizzly #2 500 kv line COI flw culd be higher with lwer exprts n P75, P76, and Redmnd while Klamath Falls generatin is high Califrnia ISO/MID H-13

14 Figure 4.2-2: Schematic Diagram f BPA system cnnecting t Califrnia BPA perfrmed a detailed study t quantify the crrelatin between the parameters impacting the NW Net Exprt capability. Figure shws that a ttal f 5,100 MW n COI and Path 76 is achievable under a wide range f Path 75 flws when Klamath Falls generatin is dispatched at high levels, which based n histrical data is expected t be the case in summer mnths. Figure 4.2-3: NW exprt capability vs. ttal COI + Path 76 flw Califrnia ISO/MID H-14

15 Analysis f COI = 5,100 MW N-S Resurce Shaping Case (Spring) The COI pick-up test fllwing the trip f ne Pal Verde unit was arund 51% f the lst generatin, which is higher than the histrically typical 42% - 45% range. The reasn is that this scenari is a spring evening case and, as a result, many Califrnia thermal generatrs are ffline and dn t respnd t lst generatin. On the ther hand, high exprt n COI and PDCI requires high hydr generatin in the PNW with relative lw spring lad, which results in high hydr generatin headrm. Similar t the Energy Transfer case in summer, if the cntingency categrizatin f tw adjacent circuits remains P7 and the RAS arming amunt desn t change, the maximum COI flw limit will remain 4,800 MW. Hwever by treating the simultaneus utage f tw adjacent 500 kv line as cnditinally credible, COI flw culd be increased t 5,100 MW at which the N-1 utage f the Rund Muntain Table Muntain 500 kv line lads the remaining line at 100%. Study results shwed that with COI flw at 5,100 MW, a simultaneus utage f Malin Rund Muntain #1 and #2 500 kv lines, caused an 18% verlad n Captain Jack Olinda 500 kv line and as a result the vltage alng the Olinda Tracy 500 kv path wuld be lw. Nte that if COI is at 5,100 MW, this duble utage is cnsidered nt t be credible and therefre is equivalent f an Extreme Event fr which planning slutins are nt required by NERC r WECC standards. Anther apprach t increase COI t 5,100 MW in the Resurce Shaping case in spring, is t increase generatin tripping in the PNW r include lad shedding in Califrnia fllwing the N-2 cntingency. BPA has indicated that increasing generatin tripping in the PNW culd be challenging. Currently there are number f lad shedding schemes in service in Califrnia t address reliability issues. By adding lad shedding t the COI RAS, it wuld be pssible t increase COI t 5,100 MW t address thermal verlads and vltage issues fllwing N-2 cntingencies. Details f the lad shedding scheme such as magnitude and lcatin shuld be defined in future studies. If required, vltage issues culd als be addressed by utilizing Fast AC Reactive Insertin (FACRI) scheme in the PNW system which culd be utilized under extreme events such as simultaneus utage f tw 500 kv lines when it was deemed nt credible. Studies Cnducted by BPA n PNW System BPA studies shwed that there were n thermal verlad issues fr a wide range f Path 75 flws with 5,100 MW simultaneus flw n COI and Path 76. Als, there were n vltage r vltage stability issues in the system with prper switching f existing reactive supprt devices in the system. Califrnia ISO/MID H-15

16 4.2.2 Near-term Assessment Suth t Nrth Flw n PDCI and COI Three study cases were develped fr this assessment; tw fr the Energy Transfer scenari and ne fr the Resurce Shaping scenari: Energy Transfer (S-N) (tw cases): Late afternn hurs in the fall with mild temperatures in Califrnia and cler weather in PNW. Califrnia lad is expected t be 60% f its peak lad with slar generatin at arund 80% f peak and wind generatin in suthern Califrnia at arund 70% f its peak. With high slar and wind generatin and lw lad in Califrnia it is expected that surplus generatin t be available t exprt f PNW. Case A: PDCI = 1,000 MW S-N, COI = 3,627 MW S-N, typical n ther paths Case B: PDCI = 1,500 MW S-N, COI = 2,543 MW S-N, typical n ther paths. Resurce Shaping (S-N): Middle f the day in the spring with mild temperatures in Califrnia and cler weather in PNW. Califrnia lad is expected t be 60% f its peak lad with slar generatin at arund 100% f peak and wind generatin in suthern Califrnia at arund 70% f its peak. With high slar and wind generatin and lw lad in Califrnia it is expected that surplus generatin t be available t exprt f PNW. PDCI = 1,500 MW S-N, COI = 2,725 MW S-N, typical n ther paths The fllwing table shws a summary f the base cases fr these S-N study scenaris: Table 4.2-2: Parameters f the PDCI suth t nrth study scenaris 2023fallffpk_etr_pdci1000sn_v fallffpk_etr_pdci1500sn_v2. Case Name 2023sp_rs_pdci1500sn_v2.sav sav sav Fall ffpeak energy transfer frm Fall ffpeak energy transfer frm Spring ff-peak energy shaping Califrnia t the Pacific Califrnia t the Pacific with PDCI at 1500 MW (S-N Case Descriptin Nrthwest with PDCI flw at Nrthwest with PDCI flw at directin) and COI at 2,725 MW (S- 1,000 MW (S-N) and with COI at 1,500 MW (S-N) and with COI at N) 3,627 MW (S-N) 2,543 MW (S-N) Year/Seasn 2023, late fall 2023, late fall Early spring 2023, arund nn Initial WECC Case 23HW1a1 23HW1a1 23HW1a1 COI (66) 3,627 MW (S-N) 2,543 MW (S-N) 2,725 MW (S-N) PDCI (65) 1,000 MW (S-N) 1,500 MW (S-N) 1,500 MW (S-N) Path 15 3,972 MW (S-N) 2,296 MW (S-N) 1,403 MW (S-N) Path MW (S-N) 239 MW (S-N) 1,120 MW (N-S) Path 46 7,276 MW (E-W) 7,435 MW (E-W) 5,088 MW (E-W) Path MW (N-S) 114 MW (N-S) 115 MW (N-S) IPP (27) 1,575 MW (E-W) 1,575 MW (E-W) 1,575 MW (E-W) NW-BC (Path 3) 1,408 MW (S-N) 1,405 MW (S-N) 1,400 MW (S-N) ISO Lad ~ 61% f peak lad ~ 61% f peak lad ~60% f peak lad ISO Slar 80% 80% 100% ISO Wind ~ 69% (SCal), 3% (PG&E) ~ 69% (SCal), 3% (PG&E) ~ 69% (SCal), 3% (PG&E) Ttal ISO Imprt -238 MW (exprt) -260 MW (exprt) -2,927 MW (exprt) Nrthern Califrnia Hydr 1,513 MW (37%) 1,513 MW (37%) 1,513 MW (37%) Califrnia ISO/MID H-16

17 Nrthern Califrnia Hydr Generatin Assumptins The nrthern Califrnian hydr generatin is nt as critical when COI is in the suth t nrth directin, cmpared t the nrth t suth studies, as it desn t impact COI limit and therefre it wasn t adjusted frm the riginal WECC case. Analysis f Suth-t-Nrth Near-term Assessment Results Fr the verlapping cntingencies (N-1-1) r N-2 (WECC Cmmn Crridr) f 500 kv lines in the same crridr but nt n the same twer the transmissin cntingency f Adelant-Tluca and Victrville-Rinaldi 500 kv lines are the mst severe utage. Study results shwed n verlading r vltage r transient stability cncerns. Fr the extreme cntingency f N-2-1 f Rinaldi-Tarzana 230 kv #1 and 2 lines, fllwed by Nrthridge-Tarzana 230 kv line, a number f 138 kv lines within LADWP s transmissin system verlad. These verlads are existing lcal area reliability cncerns that stemmed frm having n lcal generatin dispatched. A ptential mitigatin fr this issue is t dispatch lcal generatin pst first cntingency t prepare fr the next cntingency. Fr 500 kv bulk cntingencies treated as either P6 r P7 f 500 kv lines in the same crridr but nt n the same twer in nrthern Califrnia, varius 230 kv line verlads were bserved that are addressed by existing RAS schemes (i.e., inserting line series reactr n 230 kv line). The Olinda 500/230kV transfrmer als verladed fr the 1000 MW PDCI S-N study case that culd be mitigated by generatin curtailments thrugh existing r new RAS schemes t trip generatin (as a P7 cntingency) r by system readjustment after first cntingency (as a P6 cntingency). Analysis f Suth-t-Nrth Near-term Assessment Results (Sensitivity Studies) In additin t the baseline scenaris, three sensitivity studies were als assessed as fllws, based n the Resurce Shaping case: Case 1: 1500 MW PDCI S-N resurce shaping, spring ff-peak, slar generatin at 100% installed capacity, additinal lads include 600 MW Castaic pump lads Case 2: Started with Case 1 and changed PDCI dispatch t 1,050 MW S-N Case 3: Started with the 1500 MW PDCI S-N resurce shaping, and switched ff Klamath Falls generatin t reflect spring cnditin; this case had an earlier assumptin f having lcal generatin dispatch in LADWP s LA Basin. Fr Case 1, the Rinaldi 500/230kV Bank H and the Century Victrville 287kV line were verladed fr the verlapping cntingencies (N-1-1) r N-2 (WECC Cmmn Crridr) f Adelant-Tluca and Victrville-Rinaldi 500 kv lines. Fr the extreme cntingency f N-2-1 f Rinaldi-Tarzana 230kV #1 and 2 lines, fllwed by Nrthridge-Tarzana 230kV line. Thermal lading cncerns n varius 138kV lines internally within LADWP s transmissin system. These are existing lcal area reliability cncerns due t having Califrnia ISO/MID H-17

18 n lcal generatin dispatched. A ptential mitigatin is t dispatch lcal generatin pst first cntingency t prepare fr the next cntingency fr the extreme utage lading cncerns. Fr 500 kv bulk cntingencies treated as either P6 r P7 f 500 kv lines in the same crridr but nt n the same twer in nrthern Califrnia, varius 230 kv line cngestin ccurs. There are existing RAS schemes t mitigate the lcal cngestin cncerns in nrthern Califrnia (i.e., inserting a line series reactr n 230 kv lines, pening 500/230 kv circuit breakers at Rund Muntain.)Fr ther lcal cngestin cncerns in nrthern Califrnia, either include generatin curtailments t either existing r new RAS schemes t trip generatin (P7 cntingencies) r implement cngestin management prtcl fr verlapping P6 cntingencies. The Olinda 500/230kV and Rund Muntain 500/230kV transfrmers are als verladed fr 500 kv bulk cntingencies. These verlads culd be mitigated by generatin curtailments thrugh existing r new RAS schemes t trip generatin (as a P7 cntingency) r by system readjustment after first cntingency (as a P6 cntingency). The fllwing cnceptual mitigatin ptins culd help maintaining PDCI schedules and imprts int LADWP under critical cntingencies: Install tw 230kV phase shifters with 540 MVA, 0 t -40 phase angles n the Sylmar- Guld 230kV line at Sylmar end (nte that there are variatins n lcatins fr the phase shifters); OR, Install RAS t trip pump lads (this mitigatin ptin is nt favred by LADWP.) The fllwing cnceptual perating mitigatins are prvided here fr infrmatin nly. the ISO ntes that LADWP retains jurisdictinal respnsibility fr prpsing and implementing perating actins. These ptins may invlve curtailing schedules r lads under critical cntingencies: Ptential perating actins t curtail pump lads after the first cntingency; Ptential perating actins t reduce PDCI S-N flw t 1,000 MW after the first cntingency; OR, Ptential perating actins fr implementing System Operating Limit (SOL) fr VIC-LA path. Summary f Near-term Assessment Results In the nrth t suth flw: With N-2 treatment f cntingency lss f 500 kv lines in adjacent circuits, COI limit will remain 4,800 MW unless new generatin r lad shedding in included in the RAS. If the utage f tw 500 kv adjacent lines were t be cnsidered cnditinally credible cntingencies (i.e., as P6), the COI limit culd ptentially increase t 5,100 MW under favrable cnditins. Further studies are required fr a COI limit beynd 5,100 MW Califrnia ISO/MID H-18

19 In the suth t nrth flw: COI flw up t the WECC limit f 3,675 MW S-N is feasible fr certain cnditins with typical fall and spring ff-peak cnditins. PDCI flw is currently limited t 1000 MW S-N peratinally by LADWP t address mst, if nt all, winter perating cnditins. LADWP is the perating agent fr the PDCI at the suthern terminal. Hwever, under certain fall and spring ff-peak light lad scenaris, PDCI S-N flw culd be perated higher (i.e., 1,500 MW) under nrmal cnditins. Under critical cntingency cnditins, the PDCI S-N flw wuld need t be reduced t its 1,000 MW limit. Ptential transmissin upgrades, such as phase shifting transfrmers, culd be an ptin fr prviding imprts fr LADWP via the Sylmar path while maintaining PDCI S-N flw at 1,500 MW. This is explratry at this time and wuld need further assessments f engineering and peratinal feasibility. 4.3 Lng-term Assessment (Year 2028) In the lng-term assessment fr the year 2028, the bjective was t perfrm prductin cst mdeling simulatins t estimate the ptential benefits f increased AC and DC transfer capability. Assumptins n the prfile f hydr generatin in the PNW was a critical cmpnent f this study. The ISO received hydr infrmatin frm Nrthwest Pwer and Cnservatin Cuncil (NWPCC) and updated PNW hydr mdels in the prductin cst mdel t reflect the updated infrmatin PNW Hydr Mdel in Prductin Cst Mdel (PCM) The WECC Anchr Data Set (ADS) was used as a starting pint fr the prductin simulatin analysis using ABB GridView sftware. Hydr assumptins in the ADS are based n histrical hydr utput in WECC frm 2008/2009. Using publicly available infrmatin n BPA hydr generatin, the BPA hydr generatin utput frm f the 2028 PCM was cmpared with actual BPA generatin and the results are prvided in Figure The 2028 PCM prvides similar seasnal hydr generatin variatins as year 2008 actual utput, while there are sme differences cmpared t year 2017 actual utput. Califrnia ISO/MID H-19

20 Figure 4.3-1: Cmparisn between actual BPA generatin and prductin simulatin results The ISO als reached ut t the nrthwest planning regins (ClumbiaGrid and Nrthern Tier Transmissin Grup) and the hydr wners t review hydr mdeling in the ADS and make updates as required. The ISO received infrmatin n typical (medium), high, and lw hydr scenaris frm NWPCC and BPA4. NWPCC s GENESYS mdel prvides a chrnlgical hurly simulatin f the Pacific NW pwer supply that includes 34,086 MW f installed hydr capacity. 4 Califrnia ISO, Nrthwest Pwer and Cnservatin Cuncil and Bnneville Pwer Authrity. September 6th Prtland Stakehlder Wrkshp Available here: BPA. Wind generatin & ttal lad in the BPA balancing authrity Available here: US Army Crps f Engineers. Dataquery Available here: Califrnia ISO/MID H-20

21 GENESYS is used by NWPCC fr assessing resurce adequacy in the Pacific Nrthwest and cnsiders the nn-pwer requirements f the nrthwest hydr. The GENESYS mdel prvides mnthly ttal hydr generatin based n water flw patterns fr 80 years frm 1929 t T study system perfrmance under high, lw, and medium hydr cnditins, water flw patterns f years 1931, 1960, 1997 were selected that crrespnd t 5 th, 50 th, and 95 th percentile f hydr generatin. Figure shws the mnthly hydr generatin under each hydr scenari alng with the PNW hydr mdel in the ADS fr cmparisn. The ttal energy generated in a year is 100, 148, and 172 TWh fr lw, medium, and high water cnditins. Figure 4.3-2: Mnthly Hydr Generatin under High, Lw, and Medium hydr years 20,000,000 18,000,000 16,000,000 14,000,000 Energy (MWh) 12,000,000 10,000,000 8,000,000 6,000,000 4,000,000 2,000,000 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nv Dec Mnth LOW MED HIGH ADS Updating ADS hydr mdeling parameters The infrmatin prvided by NWPCC was an aggregate f all the hydr units in the PNW system. GridView sftware requires the fllwing infrmatin fr each unit: Mnthly energy (MWh) Mnthly max utput (MW) Mnthly min utput fr each year (MW) Mnthly daily average perating range (MW) Fr the majrity f the PNW units, the rated capacity f each unit was used t calculate the abve parameters fr the unit, n a pr-rata basis frm the NWPCC aggregated values. The nly exceptins were the Federal Clumbia River Pwer System Mainstem units that include a ttal f Califrnia ISO/MID H-21

22 6 prjects as shwn in Figure 4.3-3: Grand Culee, Chief Jseph, McNary, Bnneville, Jhn Day and The Dalles. Fr these units, the mnthly energy was still btained n pr-rata basis, and mnthly maximum energy, mnthly minimum energy, and daily perating range parameters were estimated based n histrical data. Figure 4.3-4, Figure 4.3-5, and Figure shw these estimated parameters fr Mainstem units fr each mnth in high, lw, and medium hydr years. Figure 4.3-3: Lcatin, Capacity, and Energy f Mainstem Units Figure 4.3-4: Min, Max, and Daily Operating Range fr Mainstem Units fr Medium Hydr Years Califrnia ISO/MID H-22

23 Figure 4.3-5: Min, Max, and Daily Operating Range fr Mainstem Units fr High Hydr Years Figure 4.3-6: Min, Max, and Daily Operating Range fr Mainstem Units fr Lw Hydr Years Califrnia ISO/MID H-23

24 4.3.2 Analysis f Lng-term Assessment Results Prductin cst mdeling simulatins were carried ut n the ISO s current PCM as a reference, as well as the three updated scenaris fr high, lw and medium hydr years. The fcus f this analysis was t assess the cngestin n COI and PDCI. In additin t these tw paths, the cngestin n Path 26 was als examined t evaluate the impact f perating limits n PDCI in the suth t nrth directin. COI Cngestin with Different Hydr Cnditins In the baseline scenari f the prductin simulatin studies, the COI path rating is the current rating f 4800 MW in nrth-suth and 3675 MW in the suth-nrth directin. Table shws the number f hurs that COI was cngested under different hydr cnditins. Nte that COI scheduled utages and derates are mdeled in the prductin cst mdel and COI cngestin mainly happened during the hurs in which COI was derated. The COI cngestin includes the cngestin f Path 66 (COI) itself as well as its dwnstream transmissin lines. A sensitivity study was perfrmed n the medium hydr cnditins assuming N-S COI path rating was 5,100 MW. Prductin simulatin results indicated that the COI cngested hurs decreased frm 387 hurs in the baseline scenari with a 4,800 MW COI rating dwn t 281 hur in the sensitivity scenari with a 5,100 MW COI rating. Table 4.3-3: COI cngestin in year 2028 prductin simulatin ISO Planning PCM Medium Lw High ISO Planning PCM with 5100 MW COI rating Medium with 5100 MW COI rating Cngestin Hur Cngestin Cst ($M) The prductin benefit fr the ISO s ratepayers and the WECC verall prductin cst savings f increasing the COI path rating t 5100 MW are shwn in Table The PNW Medium hydr cnditin was used in this assessment. This assessment shwed prductin benefit t the ISO s ratepayers, which differes frm the results in sectin f the ISO s Transmissin Plan. This is mainly because the PNW Medium hydr cnditin has higher annual energy than the PNW hydr cndtin that was mdeled in the WECC ADS and used as the baseline assumptin in the ISO s ecnmic planning study in the Transmissin Plan. It is wrth nting that the PCM fr PNW-CA study allwed hydr generatrs t respnse t system- wide LMP t reflect the ptential crdinatin between the hydr and renewable peratins. In the WECC ADS and ISO ecnmc planning PCM, hydr generatrs nly respnded t lcal LMP. Califrnia ISO/MID H-24

25 Table 7.1-4: Prductin Cst Mdeling Results fr COI path rating at 5100 MW, PNW Medium Hydr cnditin Pre prject upgrade ($M) Pst prject upgrade ($M) Savings ($M) ISO lad payment 8,083 8, ISO wned generatin prfits 2,150 2,146 4 ISO wned transmissin revenue ISO Net payment 5,743 5, WECC Prductin cst 16,172 16,173-1 Nte that ISO ratepayer savings are a decrease in lad payment, but an increase in ISO wned generatin prfits and an increase in ISO wned transmissin revenue. WECC-wide Savings are a decrease in verall prductin cst. A negative saving is an incremental cst r lss. In the ISO planning PCM, the PDCI rating in the suth t nrth directin was assumed t be 1050 MW t be cnsistent with LADWP s peratin limit n this path. A sensitivity study assuming the WECC PDCI rating that is 3100 MW in the suth t nrth directin was cnducted t assess the impact f the PDCI rating in the suth t nrth directin, n the PDCI cngestin. Table shws that PDCI was nt cngested in many hurs even when the 1050 MW rating was used. The PDCI rating increase helped t reduce Path 26 cngestin hurs frm 1029 hurs t 1022 hurs. Path 26 cngestin csts may change in either directin depending n the LMPs change n the bth side f the path, which were decided by the generatin dispatch in each hur. The ISO net exprt limit als cnstrained flw thrugh PDCI frm suth t nrth. Table shws the PDCI and Path 26 cngestins when the ISO net exprt limit was nt enfrced. PDCI cngestin hurs were reduced frm mre than 300 hurs t zer when the PDCI rating was increased frm 1050 MW t 3100 MW. In this sensitivity study, the PDCI path rating increase resulted in Path 26 cngestin reductin frm 1115 hurs t 1091 hurs. Table 4.3-5: Path 26 and PDCI cngestin in year 2028 prductin simulatin 2000 MW ISO net exprt limit scenari PDCI Limit (MW) PAC NW Hydr ISO Planning PCM ISO Planning PCM Path 26 Cngestin Cst ($M) Path 26 Cngestin Hurs PDCI Cngestin Cst ($M) PDCI Cngestin Hurs Medium Medium Califrnia ISO/MID H-25

26 Table 4.3-6: Path 26 and PDCI cngestin in year 2028 prductin simulatin N ISO net exprt limit scenari PDCI Limit PAC NW Hydr ISO Planning PCM ISO Planning PCM Path 26 Cngestin Cst ($M) Path 26 Cngestin Hurs PDCI Cngestin Cst ($M) PDCI Cngestin Hurs Medium , Medium Summary f Lnger-term Assessment Results In the nrth t suth flw: COI cngestin ccurs in all hydr cnditins with highest cngestin ccurring in high hydr scenari; and, N cngestin was bserved n PDCI in the N-S directin. In the suth t nrth flw: N cngestin n COI was bserved in the S-N directin; N cngestin n PDCI assuming WECC path rating as the limit. There wuld be cngestin n PDCI if the S-N is limited t 1050 MW; and Path 26 is cngested fr mre than 1,000 hurs in the S-N directin fr the medium hydr scenari. Califrnia ISO/MID H-26

27 5 Increase Dynamic Transfer Capability (DTC) This sectin prvides a summary f DTC limitatins and the mitigatin measures BPA is cnsidering t address them. The details are prvided in BPA DTC Radmap in Attachment 1 Dynamic transfer capability refers t the capability f the Pacific Nrthwest system t accmmdate variatins n 5-minute scheduling n Pacific Nrthwest AC Interties (NWACI). Currently the DTC n NWACI is limited t 600 MW mainly t prevent excessive vltage fluctuatins and reactive switching. The current manual RAS arming prcess culd becme anther limitatin n DTC at higher levels. Vltage stability cncerns were anther DTC limiting factr until recently but the cncerns have been addressed and they n lnger limit DTC. 5.4 Excessive vltage fluctuatins and reactive switching Frequent variatins in active pwer flws can cause excessive variatins in custmer vltages r switching f vltage cntrl devices such as shunt reactrs, capacitrs and tap changers. Custmer vltage variatins limitatins apply ver the full range f COI transfers, and are mre restrictive under high pwer transfers. Vltage variability is the limiting DTC factr abut 80% f time tday. 5.5 RAS Arming RAS arming requirements increase at a steep rate between 2,500 MW and 3,600 MW f COI flw. The system can end up in an insecure state if dispatchers are unable t keep up with manual RAS arming. 5.6 Vltage Stability Vltage stability was the limiting DTC factr abut 20% f time, mainly under utage cnditins. The reasn was that a fast ramp up f the COI pwer may have resulted in a sub-ptimal system state such that it may becme vltage unstable fr a critical cntingency. Hwever, the WECC Remedial Actin Scheme Reliability Subcmmittee (RASRS) apprved BPA s Synchrphasr RAS as wide-area prtectin effective December 1 st, 2018 and as a result vltage stability is n lnger a limit n DTC f NWACI. The Synchrphasr RAS addressed the issue as it identifies vltage stability risks using wide-area measurements and enables fast switching f shunt capacitrs and reactrs t imprve stability. 5.7 Ptential Slutins T Increase DTC BPA is perfrming studies t evaluate ptential slutins t increase the DTC. Vltage Variability Limitatin Emply Real-time Allcatin f DTC Califrnia ISO/MID H-27

28 DTC n COI is currently allcated in the day-ahead time frame. BPA is explring applying the DTC limit in real-time n the net f all mvements, instead f allcating DTC ahead f time, t allw significantly mre dynamic usage within the same stated limits. Apply DTC Limit t Actuals (instead f schedules) BPA perfrmed analysis f DTC usage, which indicated that actual five-minute flw variatins n COI differ frm DTC schedules. The actual change in flw is generally less than the magnitude f the crrespnding schedule change. BPA is cnsidering having the limit implemented by the peratr f Western EIM (i.e. Califrnia ISO) based n actual physical flws as ppsed t scheduled flws. Use DTC Nmgram Instead f a Fixed Limit. Vltage variability increases at higher COI flw fllwing a classic Pwer-Vltage (PV) curve. Currently, BPA applies a single cnservative limit crrespnding t the high COI flws. A nmgram wuld be mre apprpriate t take advantage f greater DTC at lwer COI levels. Real-Time Vltage Assessment Tls Real-time vltage assessment tls can be used t determine the dynamic transfer impact n custmer vltage variability. Hwever, based n a large number f sensitivity studies perfrmed by BPA, the benefits f using real-time tls are likely t be minimal cmpared t the DTC nmgram. Crdinated Vltage Cntrls Further increases in DTC beynd 600 MW can be achieved by deplying Crdinated Vltage Cntrls (CVC). BPA has successfully implemented Autmatic Reactive Cntrls (ARC) at wind generatin hubs t crdinate switching f BPA shunt capacitrs with vltage cntrls and reactive resurces f wind farm. Prpsed CVC will be similar in principle t ARC. Crdinatin with PG&E and TANC is required t achieve full utilizatin f COI DTC and ensure there are n vltage issues in their systems. Cntrl State Awareness and Analytics Based n past experience with ARC, implementing CVC required state awareness tls t detect ramps and cntrller switching, as well as simulatin tls t reprduce cntrller behavir. BPA is planning t determine system enhancements, perating prcedures, and analytical tls required t remve the DTC limitatin in the Pacific Nrthwest system. Withut DTC limitatins, the 5-minute scheduling n COI will be similar t the 15-minute scheduling n which there are n limits n hw much the schedule culd change frm ne scheduling interval t the next. Califrnia ISO/MID H-28

29 6 Implementing sub-hurly scheduling n PDCI Transfer scheduling n COI culd currently be dne n a 15-minute basis. Upn cmpletin f DTC initiatives discussed earlier in this reprt, it wuld be pssible t have 5-minute scheduling n COI withut any technical limitatins. With regards t PDCI, the scheduling can be dne nly n hurly basis. Having 5-minute r even 15-minute scheduling capability n PDCI wuld facilitate further utilizatin f PNW hydr t supply Califrnia lad especially during mrning and evening ramps in which the transfer requirements change quickly. A number f mdificatins in bth BPA and LADWP systems are required t facilitate sub-hurly scheduling n PDCI: AGC and EMS mdificatins at BPA system; Autmatin f PDCI RAS arming. BPA is wrking n this prject with expected cmpletin in 2020; and, Vltage variability: BPA perfrmed initial system impact studies f PDCI dynamic transfers n the PNW system. The studies indicated increased switching f pwer factr crrectin capacitrs at BPA and LADWP substatins, and further analysis f switching device duty is required. BPA will perfrm studies in 2019 t determine what AGC and ther EMS mdificatins are required. System impact studies f simultaneus COI and PDCI 5-minute scheduling are planned in 2019 as well. Fllwing up the cmpletin f BPA studies, a jint BPA/LADWP study will be perfrmed in rder t fully assess what will need t be mdified t autmate the cntrl f the DC frm AGC systems. The jint study is expected t be cmpleted in tw years. The next steps will be decided based n the utcme f the studies. System impact studies are als required t assess the impact f simultaneus COI and PDCI 5-minute scheduling. BPA is planning t perfrm these studies in Califrnia ISO/MID H-29

30 7 Assigning Resurce Adequacy (RA) Value t firm zer-carbn imprts 7.1 ISO s RA prcurement prcess The Maximum Imprt Capability is the quantity in MW determined by the ISO fr each intertie int the ISO Balancing Authrity Area t be deliverable t the ISO Balancing Authrity Area and ver which resurce capacity can be prcured by a lad serving entity fr meeting its resurce adequacy capacity bligatins. As part f annual Maximum Imprt Capability (MIC) determinatin prcess, the ISO calculates MIC n all branch grups (BG) based n the histrical hur-ahead scheduled imprt n the BGs. This calculatin is dne annually, using the histrical data ver the prir tw years. Frm all the hurs in each year in which ISO lad was higher than 90% f peak lad in that year, the highest tw scheduled imprts will be selected (ttal f 4 data pints fr each BG). The average f the abve fur data pints determines the MIC fr any BG. The ISO psts the results f this annual analysis fr all BGs n the ISO s website.5 Frm the available MIC, a prtin f the capacity may have already been allcated t entities utside the ISO in the frms f Existing Transmissin Cntracts (ETCs) and Transmissin Ownership Rights (TORs). The remaining capacity wuld be available t the Lad Serving Entities (LSEs) in the ISO-cntrlledgrid t prcure RA n the BGs. In the fllwing sectins, the MIC and available RA fr the Malin 500 BG that is part f COI as well as Nevada-Oregn Brder (NOB) which is part f PDCI is discussed in further detail. 7.2 Histrical MIC allcatin n the Malin 500 Branch Grup The Malin 500 BG cnsists f the Malin-Rund Muntain #1 and #2 500 kv lines which are part f COI (Path 66). The Malin 500 BG maximum capacity is 3,200 MW, which is tw thirds f COI s current WECC path rating f 4,800 MW. The MIC allcated t the Malin 500 BG in the last few years are prvided in Table 5.7-, which shws that in last few years arund 2,000 MW f capacity has been available n the Malin 500 BG t be used by LSEs fr RA cntracts frm resurces in the Pacific Nrthwest pdf Califrnia ISO/MID H-30

31 Table 5.7-7: Malin 500 BG MIC and Available RA fr Internal ISO LSEs Year Max limit n Malin 500 BG MIC (MW) (2/3 rds f COI limit) Allcated MIC n Malin 500 BG (MW) ETCs and TORs n Malin 500 BG held by entities utside the ISO (MW) Available RA fr Internal ISO LSEs (MW) ,983 2, , ,133 3, , ,127 3, , ,200 3,008 1,200 1, Histrical RA shwings n the Malin 500 Branch Grup The usage f available Malin 500 BG capacity fr RA in the last few years is prvided in Figure The results shw higher usage in summer mnths cmpared t ther times f the year. Figure 5.7-1: Malin 500 BG Maximum Mnthly Usage by ISO LSEs Califrnia ISO/MID H-31

32 7.4 Histrical MIC allcatin n NOB Branch Grup (PDCI) The Nevada-Oregn Brder (NOB) BG is basically the prtin f the capacity f PDCI available t ISO. The allcated MIC allcated t the NOB BG in the last few years are prvided in Table which shws that in last few years, n average, arund 1,400 MW f capacity has been available n the NOB BG t be used by LSEs fr RA cntracts frm resurces in the Pacific Nrthwest. 7.5 Histrical RA shwings n NOB Branch Grup (PDCI) The usage f available NOB BG capacity fr RA in the last few years is prvided in Figure The results shw higher usage in summer mnths cmpared t ther times f the year. Table : NOB BG MIC and Available RA fr Internal ISO LSEs Year Max limit n NOB BG MIC (MW) Allcated MIC n NOB BG (MW) ETCs and TORs n NOB BG held by entities utside the ISO (MW) Available RA n NOB BG fr Internal ISO LSEs (MW) ,564 1, , ,564 1, , ,294 1, , ,294 1, ,270 Califrnia ISO/MID H-32

33 Figure 5.7-1: NOB BG Maximum Mnthly Usage by ISO LSEs 7.6 COI and PDCI Flws in Real Time Figure shws the daily variatin f flws n COI and PDCI in March and August Each plt shws 0 (minimum), 10 th, 25 th, 50 th (median), 75 th, 90 th and 100 th (maximum) percentile f flws n COI and PDCI fr any given hur f the day in March and August Review f March data shws significant flws n bth paths during hurs withut sunshine. Flws drp during the day with lw lad in Califrnia in March as well as significant slar generatin. High flws at night are ccurring despite relatively lw RA shwings in March. Review f August data shws significant flws almst in all hurs with slightly higher flws during evening ramp n bth paths. This is in line with RA shwings which are relatively higher in summer mnths. Califrnia ISO/MID H-33

34 Figure 7.6-1: Actual Daily Flws n COI and PDCI in March and August Ptential barriers fr higher RA shwings As per CPUC/ISO requirements, cmmitment f firm capacity is required 45 days ahead f the perating mnth in rder t be cunted twards RA. This might be challenging fr sme hydr units t frecast hydr that far in advance. Als fr sme entities, serving lcal lads takes pririty ver exprt t Califrnia. Als currently the FERC-apprved ISO RA Imprt allcatin prcess is ne year at a time. Sme LSEs prefer t sign multi-year cntracts. In general, firming up capacity and energy ging thrugh number f Balancing Authrity Areas may results in additinal cst cmpared t internal Califrnia resurces. 7.8 Summary f RA Analysis Cmparisn f histrical data fr available capacity n COI and PDCI fr RA cntract, and the RA shwings n these branch grups indicates that except fr summer mnths, the RA shwings are less than available MIC. While RA shwings are lw fr nn-summer mnths, the actual flw n COI and PDCI is quite high. The histrical flws n COI and PDCI that are used in the MIC determinatin makes available almst the ttal ISO share f the COI path rating fr RA; hwever as indicated the RA prcured Califrnia ISO/MID H-34