Technical Bulletin. Generation Interconnection Procedures. Revisions to Cluster 4, Phase 1 Study Methodology

Transcription

1 Technical Bulletin Generatin Intercnnectin Prcedures Revisins t Cluster 4, Phase 1 Study Methdlgy Release Date: Octber 20, 2011 (Finalizatin f the Draft Technical Bulletin released n September 19, 2011) Page 1 f 6

2 Executive Summary An alternative methdlgy t the phase 1 analysis f the netwrk upgrades fr intercnnectin queue Cluster 4 will be used t assess an intercnnectin custmer s cst respnsibility ceiling and psting requirements fr Cluster 4 generatin. This alternative methdlgy was develped ut f a cncern that, if the current methdlgy were applied in phase 1, the unprecedented vlume f generatin requests received in Cluster 4 wuld likely result in unrealistic results, in the sense that the results wuld be tailred t a generatin prtfli f size and scpe that that is unlikely t cntinue thrugh the intercnnectin prcess, given anticipated pwer supply needs. This alternative phase 1 study methdlgy cnsiders studying a mre realistic amunt f generatin in each study area, based n the greater f the generatin amunts studied in Cluster 3, phase 1, r the highest amunt f generatin frecast in any f the CPUC (Lng Term Prcurement Plan) LTPP renewable generatin prtflis. The delivery netwrk upgrade cst results assciated with these mre realistic generatin amunts ($/MW) will then be extraplated acrss all the Cluster 4 generatin that has applied fr intercnnectin in the study area. Individual generatin intercnnectin facilities (i.e., the upgrades/mdificatins needed t reliably attach the generatin prject t the grid) will cntinue t be studied n a generatr-specific basis. This alternative phase 1 study methd is expected t prvide mre realistic results fr phase 1 purpses that anticipate the inevitable withdrawal f a prtin f the generatin in the clusters. N change in methdlgy is expected fr phase 2 analysis, and all generatin that cntinues t advance frm Cluster 3 and Cluster 4 phase 1 will be studied tgether in the Cluster 3 and 4 phase 2 prcess. The alternative phase 1 study methdlgy therefre des nt impse a limit n the amunt f generatin that actually prceeds thrugh phase 2, and the netwrk upgrades assessed in phase 2 will be based n the generatin prjects that elect t cntinue frward t phase 2. Backgrund The purpse f cluster studies is t identify the intercnnectin facilities and netwrk upgrades that wuld be necessary t integrate the generatin seeking intercnnectin t the transmissin system, t estimate the csts f thse upgrades and t establish the maximum cst respnsibility f each f the generatin prjects in the cluster. The cluster study apprach has prved an effective way t manage a large number f simultaneus intercnnectin requests. The study methdlgy used t assess netwrk upgrades necessary t supprt each cluster f generatin layers the new cluster f generatin upn all existing generatin and all previus intercnnectin requests that remain active, as well as the netwrk upgrades assciated with the active previus intercnnectin requests r apprved thrugh the ISO s transmissin planning prcess. The unprecedented vlume f generatin in Cluster 4 has raised particular cncerns that under the existing apprach the resulting transmissin plans fr netwrk upgrades will nt prduce realistic and meaningful results fr the phase 1 analysis, and that there be little, if any, crrespnding relatinship between the methds f service set frth in the phase 1 study results and thse in the phase 2 study results.. Cluster 4 alne has added 35 GW f renewable generatin t bring the ttal renewable generatin in the queue t 68 GW, in a market with a peak lad f 50 GW and in which the expected need fr new renewable generatin is abut 20 GW. Stakehlders and thers have cmmented that a cmparisn f ptential supply surces t system histric size and anticipated near term needs cmpels the cnclusin that a substantial number f prpsed prjects will nt be cmpleted. Page 2 f 6

3 The ISO has therefre develped an alternative methdlgy fr cnducting the individual study cmpnents set ut in GIP Sectin 6.4 fr phase 1 intercnnectin studies. The alternative methdlgy relies n the methdlgy principles emplyed previusly but includes adaptatins t prduce mre reasnable and useful results while still accmmdating the needs f intercnnecting parties. The representative MW number fr each study area will be incrprated int the phase I study as a study assumptin. 1 The ISO will apply this methdlgy t the phase 1 study prcess. With respect t the cmbined Cluster 3 and Cluster 4 phase 2 intercnnectin study, any ISO decisin regarding the pssible emplyment any methdlgy ther than the current methdlgy fr phase 2 studies wuld be based n the respnses f the cluster 3 and 4 generatin develpers t their phase 1 csts (i.e. the number f prjects and MW generating capacity that wuld pst the initial financial security psting, thus electing t prgress t phase 2). As f the date f this technical bulletin, the ISO des nt anticipate that any changes will be made t the phase 2 intercnnectin study analysis prcess This technical bulletin sets ut the backgrund and issues that led the ISO t the cnclusin that methdlgy changes are required fr phase 1 f Cluster 4, an alternative methdlgy, and the issues assciated with implementatin f the alternative. The primary cncepts characterizing the alternative are t (1) limit the amunt f new generatin t be studied in the Cluster 4 phase 1 study t a mre reasnable and realistic quantity in each study area, based n a cmbinatin f the resurce prtflis develped by the CPUC and anticipated t be adpted by the ISO fr the 2011/2012 transmissin planning cycle and the Cluster 3 phase 1 results; and (2) establish phase 1 cst caps fr the Cluster 4 generatin prjects by extraplating the cst results. As stated abve, n methdlgy changes are anticipated fr the phase 2 analysis f Cluster 4. The generatin studied in Cluster 4 phase 2 (which will be cmbined with e Cluster 3 analysis) will be based n all generatin prjects that elected t mve frward thrugh the ISO s intercnnectin prcess, and the amunt studied in each area will nt be limited by the generatin amunts assumed in the Cluster 4 phase 1 analysis. It is imprtant t nte that the alternative phase 1 study methdlgy referenced in this technical bulletin applies nly t the Cluster 4 phase I analysis f custmer delivery netwrk upgrades,and NOT t analysis f reliability netwrk upgrades r the PTO s intercnnectin facilities. The ISO will examine reliability netwrk upgrades and intercnnectin facilities individually r in small grups. Objectives f the Phase 1 Cluster Study T be useful and effective, the Phase 1 cluster study effrts shuld accmplish the fllwing bjectives. 1. Identify transmissin facility cmpnents. Prvide a realistic initial assessment f the additinal netwrk upgrades needed t fulfill the intercnnectin requests f prjects in the cluster that anticipate the inevitable withdrawal f a prtin f the generatin in the clusters, given the current status f prjects earlier in the ISO queue and the netwrk upgrades identified fr thse earlier prjects r apprved in the TPP; 1 In this regard, GIP Sectin 6.4 prvides that The Phase I Intercnnectin Study will state fr each Grup Study r Intercnnectin Request studied individually (i) the assumptins upn which it is based, (ii) the results f the analyses, and (iii) the requirements r ptential impediments t prviding the requested Intercnnectin Service t all Intercnnectin Requests in a Grup Study r t the Intercnnectin Request studied individually. (emphasis added..) Page 3 f 6

4 2. Estimate Csts. Result in reasnable cst estimates fr the identified netwrk upgrades based n anticipatin f the inevitable withdrawal f a prtin f the generatin in the clusters, s as t establish a cst cap fr each generatin prject in the cluster that reflects, with reasnable accuracy, the maximum dllar amunt the prject spnsr will be required t up-frnt fund fr its share f the needed netwrk upgrades. As explained belw, the GW vlume f prjects in Cluster 4 makes it unlikely that the current methdlgy can meet these bjectives. The prblem is that the GW vlume may be s large as t prduce results well beynd the realm f plausibility the identificatin f netwrk upgrades that wuld be prduced fr the first bjective. GIP Sectin 6.4 describes the bundle f studies which cmprise a phase 1 intercnnectin study. These cnsist f A shrt circuit analysis, a stability analysis t the extent the CAISO and applicable Participating TO(s) reasnably expect transient r vltage stability cncerns, a pwer flw analysis, including ff-peak analysis, and an On-Peak and Off-Peak Deliverability Assessment(s), as applicable, in accrdance with GIP Sectin The GIP des nt mandate a specific methdlgy under which the ISO and applicable Participating TO perfrm the n-peak and Off-Peak Deliverability Assessments. Rather sectins and state that the ISO shall utilize a methdlgy that it psts t the CAISO Website r include in a BPM. This technical bulletin describes the alternate (i.e. revised) methdlgy by which the ISO will perfrm the deliverability assessments fr Cluster 4. The current study methdlgy: Under the cluster study apprach, the ISO first grups the intercnnectin requests int study areas. The ISO defines the study areas based n gegraphy and netwrk tplgy.. The defined study areas are intended t grup tgether generatin prjects that will impact the same transfer paths n the grid and therefre will be respnsible fr shares f the same netwrk upgrades. The current cluster study apprach next calls fr the ISO t d the fllwing fr each study area, fcusing n ne study area at a time: - Within the study area: - Mdel all existing generatin, generatin remaining active frm prir serial r cluster prcesses, and the related transmissin frm thse prjects, - Layer n all f the Cluster 4 generatin in that area, - Mdel a dispatch f the Cluster 4 generatin in the study area as fllws: Initially dispatch at 80% f each generatr s capacity; Next, increase generatin in the study area up t a maximum f 1500 MW additinal utput by ramping up as many as 20 f these Cluster 4 generating facilities. Under the mdel prtcl, thse generatrs identified fr adjustment (i.e., ramping up) are the nes with the mst significant impact n the transmissin system limitatin being studied. - Outside f the study area - Next, the generatin in ther areas utside f the study area are dispatched dwn t create sufficient demand t balance the generatin in the study area t the lad/demand in the subject area. - The netwrk upgrades necessary t meet the requirements f the new generatin are then determined and allcated amng all f the generatin having a material impact (i.e., at least a 5% shift factr) n the transfer path the netwrk upgrades are reinfrcing. Page 4 f 6

5 Applicatin f current methdlgy t Cluster 4 Phase 1: While this methdlgy has generally prduced realistic and therefre useful results in previus phase 1 cluster studies up thrugh Cluster 2, applying the same methdlgy fr Cluster 3 has intrduced cncerns that unrealistic generatin develpment scenaris resulted, which then dictate unrealistic transmissin plans being prduced, due t a large number and aggregate GW generating capacity f generatrs seeking t intercnnect in areas where there is general recgnitin that nly a prtin f generatrs will ultimately be sited. Because the current methdlgy accmmdates the ttal MW quantity f all generatin that has submitted an intercnnectin request within the queue, the resulting transmissin plan can appear t ver-state the GIP-driven netwrk upgrades that will ultimately be needed. This situatin is exacerbated in the Cluster 4 phase 1 analysis, as Cluster 4 includes clse t 35 GW f renewable capacity alne (with the peak lad in the ISO s entire ftprint reaching nly 50 GW) and bringing the ttal amunt f renewable generatin in the ISO queue t ver 68 GW. In cntrast, the ISO s ftprint requires less than 20 GW f new renewable capacity t reach the 33% RPS gals by In reviewing the Califrnia Public Utility Cmmissin (CPUC) generatin prtflis that the ISO is planning t use in the 2011/2012 transmissin planning cycle, it is bserved that, in a number f areas, the generatin included in Cluster 3 and earlier prcesses already surpasses the amunt f generatin expected in thse areas under any scenari in the CPUC prtflis. The additin f Cluster 4 generatin bviusly increases this versubscriptin. Methdlgy fr Cluster 4 Phase 1 Study In respnse t the cncerns expressed by interested parties with the applicatin f the current methdlgy t the Cluster 4 phase 1 generatin intercnnectin queue, the ISO has develped an alternative fcusing n the fllwing design principles: - Reasnable and Useful: prvide meaningful estimated csts and useful transmissin develpment plans. - Efficient: make best use f past technical analysis and study effrts. The results f this methdlgy, t be emplyed nly in phase 1 analysis, will be used fr all purpses the results f the current methdlgy are used fr, including setting the ceiling fr netwrk upgrade csts fr the generatrs in cluster 4. The stages in the revised methdlgy are: Step 1 Assess whether a methdlgy change is apprpriate fr each specific study area: - Assess the maximum amunt f generatin frecast in each area by 2020 in any f the identified CPUC prtflis (t be referred t as the CPUC study area ceiling). - Fr study areas in which the ttal generatin, including Cluster 4 applicatins, is less than the maximum identified in any f the CPUC s generatin prtflis, n changes will be made t the methdlgy (i.e. the current methdlgy, which incrprates all Cluster 4 MW int the study area, will be utilized). Page 5 f 6

6 - Fr study areas where the Cluster 3 and highest PUC prtfli amunts d nt prvide a representative price signal fr the additin f new generatin, then the ISO will apply the current methdlgy fr that study area r therwise make the necessary adjustment. Examples f these circumstances include: Applying the current methdlgy may be necessary if there were n material generatin in Cluster 3 r the CPUC prtflis, but cnsiderable Cluster 4 applicatins. Applying an adjustment t the price signal frm Cluster 3 may be necessary if the price signal was based n intercnnectins t ne vltage level in the system, but applicatins in Cluster 4 are seeking intercnnectins t a lwer vltage, necessitating further upgrades. Step 2 - Determining delivery netwrk upgrades and csts: - Fr each study area where Cluster 3 results are already based n mre generatin than was identified in any f the CPUC prtflis fr that area, the Cluster 3 delivery netwrk upgrades and csts will be carried frward t the Cluster 4 cst allcatin stage. - Fr each study area where Cluster 3 results are based n less generatin than the highest CPUC prtfli area result, delivery netwrk upgrades will be identified and csts will be estimated that wuld supprt the ceiling established in the CPUC prtflis. The incremental netwrk upgrades and csts will be added t the upgrades and csts t supprt Cluster 3 generatin, s that the ttal upgrades and csts will reflect all f Cluster 3 and the prtin f Cluster 4 generatin necessary t reach the CPUC ceiling fr the study area. Step 3 Allcatin f delivery netwrk upgrade csts t Cluster 4 generatin: - Determine fr the study area the $/MW netwrk upgrade cst by dividing the netwrk upgrade csts identified in Step 2 by the incremental generatin in that area. The incremental generatin is the Cluster 3 generatin plus the Cluster 4 generatin added t the study area (if any) t reach the CPUC ceiling fr that study area. - Apply the $/MW value t each prject in the study area t the capacity f that prject, t determine the netwrk upgrade cst respnsibility fr that prject. Step 4 Determining intercnnectin and reliability netwrk upgrades and csts: - The alternative methdlgy des nt extend t these elements. Accrdingly, each generatin prject will be assessed individually r in a grup t develp cnceptual intercnnectin and reliability netwrk upgrades and t estimate their csts. Page 6 f 6