TheLowerSnakeRiverDamsPowerReplacementStudy
April4,2018
Aboutthestudy
ThestudywasundertakentoinvesCgatethetechnicalfeasibilityandcostofreplacingthefourLowerSnakeRiverDamswithaporFolioofcleanandrenewableresourcesthatsupportareliableandadequateregionalpowersystemwhileminimizingincreasestogreenhousegasemissions.ThestudyseekstodevelopadeeperunderstandingoftheopConsforreplacingthegridservicestheLowerSnakeRiverDamsprovidetotheregionalpowersystem,whilealsoestablishingananalyCcframeworkthatusesmodelsandmetricsfamiliarintheNorthwest.ThestudywascommissionedbytheNWEnergyCoaliConandconductedbyEnergyStrategies,anindependentconsulCngfirmfoundedin1986andbasedinSaltLakeCity,Utah.EnergyStrategiesclientsincludepowerproducers,transmissiondevelopers,uCliCes,andgovernmentagenciesthroughoutNorthAmerica.
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WHY
?HO
W?
WHO
?
Thedams,thefish,andtheopportunity
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RestoraConoffishpopulaConsholdsgreatpromisefortheregionandit’srequiredbytheEndangeredSpeciesAct.
TheNorthwestPowerandConservaConCouncilhassaidweneedsustainedreturnratesof2%–4%forsalmonsurvivaland4%–6%tomovetowardsrecovery.Inthelast20years,returnratesforwildSnakeRiversalmonhavelargelyhoveredbetween0.5%and1%—farbelowwhat’srequiredforwildsalmontosurviveandthriveintothefuture.
SalmonrecoveryisessenCaltosavingotherendangeredspecies,includingorcawhales.RestoraConwouldalsospurgrowthintheregion’scommercialandsportfishingindustries,anditwouldbenefittownsandtribalcommuniCesinwhichsalmonplayacentraleconomicandculturalrole.
Despitemanyeffortsandgreatexpense,fishpopulaConsarenotrecovering.
Summaryfindings
• BalancedporFoliosofcleanenergyresources,includingsolar,wind,energyefficiency,demand-response,andstoragecanreplacethepowerthefourLSRDamscontributetotheNorthwestregion.
• CleanporFolioswereequalorsuperiortoanAllGasalternaCveforadequacy,gridstability,andreliability.
• ThecostsofbalancedcleanreplacementporFoliosaresmallcomparedtothecostoftheregionalpowersystem.
• AbalancedcleanreplacementporFoliohasonlyaminorimpactonGHGemissions(about1%).IfimplementedinconjuncConwitharegionalGHGreducConpolicy,substanCalreducConsinGHGemissionscanbeachieved.
• Newgas-firedgeneraConisnotrequiredtoaddressregionalcapacityneeds.
• ThestudydidnottrytoidenCfyanopCmalcleanenergyreplacementporFolio.AnefforttodososhouldproduceevenmorecosteffecCveandenvironmentallyefficientoutcomesthantheporFoliosconsideredinthisanalysis.
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“TheregioncanremovethefourlowerSnakeRiverdamsandreplacethepowertheyprovidewithapor;olioofconserva<onandrenewableenergyresourceswhilemaintaininggridandtransmissionreliabilityatlevelsequaltoorbe?erthanthecurrentsystemandwithli?leornoincreaseingreenhousegasemissions.”
TheLowerSnakeRiverDamPowerReplacementStudy,April2018
Processandstructure
• Thestudywasconductedin3phases:– IdenCficaConandquanCficaConofgridservicesprovidedbytheLowerSnakeRiverDams.– DevelopmentofreplacementporFoliosthatmeetorexceedreliability,energy,andadequacyneeds.– AssessmentoffixedandvariableproducConandoperaCngcoststoimplementthereplacement
porFoliosandtheireffectonmarketpricesandgreenhousegasemissions.
• ThestudystartedwithaReferenceCaseinwhichthedamsremaininoperaConunderexisCngpoliciesandinaccordancewiththeNorthwestPowerandConservaConCouncil’s20-yearPowerPlanand5-yearAcConPlan.ItthenconsideredthreereplacementporFolios,whichallstartwiththe7thPlanassumpConsforacquiringenergyefficiency,demandresponse,andrenewableenergyresources.TheporFoliosthenaddresourcesasrequired.
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Non-Genera<ngAlterna<vePor;olioWouldreplacepowerfromthedamswithfeasiblelevelsofdemandresponse,energyefficiency,baherystorage,andincrementalmarketpurchasesofelectricity
BalancedPor;olioWouldreplacepowerfromthedamswithacombinaConofdemandresponse,energyefficiency,andwindandsolargeneraCon
All-GasPor;olioWouldreplacepowerfromthedamswithamixofcombinedcycleandreciprocaCngenginenaturalgas-firedgenerators
• Coordinated modeling framework used three modeling tools to look at replacement portfolio impacts to reliability, resource adequacy, operations, and cost.
• Initial portfolios were developed,
tested, and adjusted iteratively. • The clean replacement portfolios
included “Plus” versions that ramped-up the level of clean energy resources.
• Modeling resulted in robust
comparisons of all replacement portfolios with the Reference Case.
Study framework
RegionalResourceAdequacyAnalysis
(GENESYSmodel)
EvaluateSystemReliability
(ColumbiaGridSummer&Winterpowerflowin
PowerWorld™)
Produc<onCostModelSimula<on
(WECC2026CommonCaseinABBGridView™)
Es<mateCostsandRateImpacts(annualizedcostofporGolio)
DevelopandIterateReplacementPor;olios
Por;olioData
CommonModelingPla;orm
• Three models were used to evaluate Pacific Northwest region
o Two models represent the entire WECC-footprint. The third represents ties and market purchases with neighboring areas.
o British Columbia and Alberta are factored in all three models.
• Lower Snake River Dams are modeled explicitly.
• Replacement portfolios are modeled with high-granularity (e.g. new resources sited at specific substations, demand response assigned to appropriate load types).
Geographic scope of the study
LowerSnakeRiverDamsWesternUS
ThereplacementporFolios
RESOURCECOMPOSITIONOFTHEREPLACEMENTPORTFOLIOSThebaseBalancedandNon-GeneraCngAlternaCve(NGA)porFolioswereenhancedbytheaddiConofextraresourcestocreate“Plus”versions.TheresulCngporFoliosaswellastheAllGasporFoliowerethenmodeledfortheireffectsbothundercurrentlawandunderascenarioinwhichNorthweststatesadoptcarbonpricingpolicies.
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Models,datasources,andassumpCons
ResourceadequacywasassessedusingtheNorthwestPowerandConservaConCouncil’sGENESYSmodel.ReliabilityandpowerflowcharacterisCcsweremodeledusingPowerWorld.ProducConcostsandgridstabilityweremodeledusingABB’sGridView.Wind,solar,andbaherystoragelevelizedcostswerecalculatedusingthe2017WECCCapitalCostModel.DataforthestudywasprovidedbyWECC,ColumbiaGrid,andtheNorthwestPowerandConservaConCouncil.
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Findings:Adequacy&reliability
AllthreereplacementporFoliosreducedthelikelihoodofcurtailmentsandthemagnitudeofloadlossintheeventofcurtailments.The“Plus”porFolioswerethebest-performingintermsofsystemadequacy.
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MagnitudeofCurtailmentsProbabilityofCurtailments
Findings:Cost
• TheBalancedPlusporFolioincreasesthesystemrevenuerequirementby3%starCngin2026,whichtranslatestoa$1.28permonthincreasefortheaverageresidenCalcustomer.Thefigureincreasesslightlyto3.21%or$1.38permonthifNorthweststatesimplementgreenhousegaspolicies.
• TherevenuerequirementfortheBalancedPlusporFolioislessthanthatoftheAllGasporFolio.• Ifcostsforwindpower,solarpower,andstorageconCnuetheircurrentdeclines,costsmaybelower.This
isreflectedinthecolumnCtled,“BalancedPlusw/LowRenewableCostSensiCvity”.
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Findings:Greenhousegasemissions
TheBalancedPlusporFoliogeneratesenoughcleanelectricitytomiCgatetheimpactonregionalemissionstolessthan1%.
WhentheBalancedPlusporFolioiscombinedwithregionalgreenhousegaspolicy,emissionsdeclineby2%.
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DecreasesinGHGemissionsarefeasibleiftheLowerSnakeRiverDamsarereplacedbycleanenergyporFoliosthatareimplementedinparallelwithaGHGreducConpolicy.
0%
5%
10%
15%
-2% -1% 0% 1% 2% 3% 4% 5% 6% 7% 8% 9%
ChangeinTotalRevenue
Requirement(%)
ChangeinAnnualCO2Emissions(%)
ChangestoRegionalRegionalCostsandCO2Emissions • When the Balanced portfolio was modified to
include additional renewable resources and then modified further to include a regional GHG policy, carbon emissions are fully mitigated at a relatively low incremental cost .
• The All Gas portfolio started with much higher
emissions and, when mitigated by GHG policy, was more costly and higher emitting than the Balanced portfolio.
• An optimized portfolio may result in lower costs
without increases in GHG emissions.
Costs and emissions summary
+RegionalGHGpolicy
+RegionalGHGpolicy
+RegionalGHGpolicy
+EEuptoTechnicalAchievablePoten<al(+560aMW)
+750MWwind+500MWsolar
BalancedPor;olios
NGAPor;olios
AllGasPor;olios
ReferenceCase
PolicyimplicaCons
TheLowerSnakeRiverDamsPowerReplacementStudyhasimportantimplicaConsforthecourt-orderedreviewprocessnowbeingconductedbythefederalagenciesthatownandoperatethedams.
1. Thestudyshowsthatremovalofthedamsandreplacementoftheenergytheygeneratewithcleanandrenewableresourcesisaviable,effecCveandaffordableopCon.ThestudyalsooffersaframeworkfromwhichthefederalagenciescandrawastheydevelopanewplanfordamoperaCons.
2. ThecleanenergyporFoliosdevelopedinthestudycanbeimprovedupon.AlthoughthisstudydemonstratestheviabilityofreplacingpowerfromthefourLSRDamswithcleanandrenewableresources,itdidnotseektoidenCfytheopCmalcleanenergysoluCon.Thecourt-orderedprocessoffersagreatopportunityforthefederalagenciestoidenCfymorecosteffecCveandenvironmentallyefficientporFoliosthanthoseconsideredinthisanalysis.
3. Afullstudyofdamremovalneedstoaddressfactorsbeyondthescopeofthisstudy.Thesefactorsincludethecostsofdecommissioningthedamsaswellascostsavingsfromdamremoval,includingthehundredsofmillionsofdollarsthatwillbeneededinthenextfewyearstoreplacethedams’agingturbines.
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