__NERC_wind

8/21/2019 __NERC_wind

1/242

Arnold SchwarzeneggerGovernor

INTERMITTENCY ANALYSIS PROJECT:APPENDIX B

IMPACT OF INTERMITTENT

GENERATION ON OPERATION OFCALIFORNIA POWER GRID

Prepared For:

California Energy CommissionPublic Interest Energy ResearchProgram

Prepared By:GE Energy Consulting

Xinggang BaiKara ClarkGary A. JordanNicholas W. MillerRichard J. Piwko

PIER

FINA

LPROJECTREPOR

T

July 2007CEC-500-2007-081-APB

8/21/2019 __NERC_wind

2/242

Prepared By:GE Energy ConsultingRichard J. Piwko

1 River RoadBuilding 2, Room 644Schenectady, NY 12345Commission Contract No. 500-02-004Commission Work Authorization No: MR-017

Prepared For:

Public Interest Energy Research (PIER) ProgramCalifornia Energy Commission

Dora Yen Nakafuji, Ph.D.

Contract Manager

Gerald Braun

Program Area Lead

PIER Renewables

Ken KoyamaActing Office Manager

Energy Generation Research Office

Martha Krebs

Deputy Director

ENERGY RESEARCH & DEVELOPMENT DIVISION

B. B. Blevins

Executive Director

DISCLAIMER

This report was prepared as the result of work sponsored by the California Energy Commission. It does not necessarily represent the views of tEnergy Commission, its employees, or the State of California. The Energy Commission, the State of California, its employees, contractors ansubcontractors make no warrant, express or implied, and assume no legal liability for the information in this report; nor does any party represethat the uses of this information will not infringe upon privately owned rights. This report has not been approved or disapproved by the CalifornEnergy Commission nor has the California Energy Commission passed upon the accuracy or adequacy of the information in this report.

8/21/2019 __NERC_wind

3/242

i

Table of Contents

ListofFigures ................................................................................................................................... v

ListofTables.................................................................................................................................... xi

Executive

Summary..........................................................................................................................1

StudyOverview ...........................................................................................................................1

Conclusions...................................................................................................................................3

Recommendations .......................................................................................................................3

GenerationResourceAdequacy ...........................................................................................4

TransmissionInfrastructure..................................................................................................8

RenewableGenerationTechnology,Policy,andPractice.................................................9

Closure...................................................................................... Error!Bookmarknotdefined.

1.0Introduction ...............................................................................................................................11

1.1.Challenges.............................................................................................................................11

1.2.Background...........................................................................................................................11

1.3.IntermittentGenerationDefinition ...................................................................................12

1.4.OverviewofProjectObjectives,TasksandParticipants................................................12

1.5.Participants ............................................................................................................................15

2.0StudyApproach ........................................................................................................................17

2.1.StudyScenarios ....................................................................................................................17

2.2.TypesofAnalysis.................................................................................................................20

2.3.Data........................................................................................................................................21

2.4.Terminology .........................................................................................................................22

3.0StatisticalAnalysis ....................................................................................................................23

3.1.TemporalandSpatialPatterns...........................................................................................23

3.1.1. DailyandSeasonalVariations .............................................................................23

3.1.2. SpatialVariations...................................................................................................28

3.1.3. YearlyVariationandPenetrationRelativetoSystemLoad.............................29

2006and2010Penetration..............................................................................................33

2020YearlyVariationandPenetration.........................................................................36

3.2.HourlyVariability................................................................................................................38

3.2.1. 2006VariabilityRelativetoLoadLevel ..............................................................40

3.2.2. 2010Variability.......................................................................................................41

RelativetoLoadLevel ....................................................................................................43

RelativetoTimeofDay .................................................................................................45

8/21/2019 __NERC_wind

4/242

ii

Sustained3HourChanges ............................................................................................48

ExtremeChanges.............................................................................................................50

3.2.3. 2020VariabilityRelativetoLoadLevelandTimeofDay...............................54

3.3.IntraHourVariability .........................................................................................................57

3.3.1. Selected

Periods......................................................................................................58 3.3.2. IntraHourVariabilityDefinitions.......................................................................59

3.3.3. 2010XVariabilityatLightLoad ...........................................................................62

3.4.VariabilitySummary ...........................................................................................................65

3.5.HourlyForecastError .........................................................................................................67

3.5.1. DayAheadForecastError ....................................................................................67

3.5.2. HourAheadForecastError..................................................................................75

3.6.Summary...............................................................................................................................77

4.0ProductionSimulationAnalysis.............................................................................................79

4.1.1. GeneralDatabaseCreation ...................................................................................80

4.1.2. ScenarioDescription..............................................................................................81

4.2.Economics .............................................................................................................................82

4.3.IntermittentRenewableForecasting .................................................................................90

4.4.Operations.............................................................................................................................95

4.4.1. CaliforniaHydroelectricOperation ..................................................................103

4.4.2. CombinedCycleOperation................................................................................106

4.4.3. RampRateandRangeofOperation..................................................................108

4.4.4. Sensitivities ...........................................................................................................114

4.5.Emissions ............................................................................................................................121

4.6.TransmissionPathLoading..............................................................................................122

4.7.Observations.......................................................................................................................126

5.0QuasiSteadyStateAnalysis..................................................................................................129

5.1.OverviewofMethod .........................................................................................................129

5.1.1. StudyPeriods........................................................................................................130

5.1.2. InputData .............................................................................................................131

5.1.3. BoundaryConditions ..........................................................................................132

5.2.SystemPerformanceExamples........................................................................................133

5.2.1. JulyMorningLoadIncrease ...............................................................................133

5.2.2. MayNightLowLoadLevel ...............................................................................141

IncreaseManeuverableGeneration ............................................................................144

8/21/2019 __NERC_wind

5/242

iii

TemporaryCurtailmentofWindGeneration ...........................................................148

RemoveLargeStepsfromLoadProfile......................................................................150

5.2.3. JuneEveningLoadDecrease..............................................................................153

IncorporateHourlyWindForecast.............................................................................157

Temporary

Wind

Ramp

Rate

Limit ............................................................................1595.3.SummaryofResults...........................................................................................................161

6.0OperationalImplicationsandMitigationMethods ...........................................................163

6.1.Validation............................................................................................................................163

6.2.StatisticalResultsandOperationalFlexibility...............................................................169

6.2.1. OverallRequirements..........................................................................................170

6.2.2. LightLoadRequirements ...................................................................................172

6.2.3. Extremes................................................................................................................174

6.3.OperationalFlexibility ......................................................................................................175

6.3.1. Forecasting ............................................................................................................175

ImplicationsofIgnoringForecasts..............................................................................176

6.3.2. UnitCommitmentandScheduleFlexibility.....................................................177

HydroelectricGenerationShift....................................................................................177

AvailableDispatchRange............................................................................................178

6.3.3. LoadFollowing ....................................................................................................179

ImpactofPumpsonLoadFollowing.........................................................................181

ImpliedCostsofLoadFollowing ...............................................................................182

6.3.4. Regulation .............................................................................................................183

ImpactofPumpsonRegulation..................................................................................183

CPS2Discussion ............................................................................................................185

ImpliedCostsofRegulation ........................................................................................186

6.4.MitigationMethods ...........................................................................................................186

6.4.1. UnitCommitmentandScheduleFlexibility.....................................................186

6.4.2. LoadFollowing ....................................................................................................187

6.4.3. Regulation .............................................................................................................187

7.0ConclusionsandRecommendations ....................................................................................188

7.1.ObservationsbyTimeFrame ...........................................................................................188

7.1.1. DayAheadandOverallOperation ...................................................................188

7.1.2. HourlyScheduleFlexibility................................................................................188

7.1.3. 5MinuteLoadFollowingandEconomicDispatch.........................................189

8/21/2019 __NERC_wind

6/242

iv

7.1.4. 1MinuteRegulation............................................................................................190

7.2.Conclusions.........................................................................................................................190

7.3.Recommendations .............................................................................................................190

7.3.1. GenerationResourceAdequacy.........................................................................191

7.3.2. Transmission

Infrastructure ...............................................................................1957.3.3. RenewableGenerationTechnology,Policy,andPractice ..............................196

7.4.Closure ................................................................................................................................197

8.0References ................................................................................................................................198

Glossary..........................................................................................................................................199

AppendixA.SummaryofWindProjectsbyScenario.............................................................203

AppendixB.SummaryofSolarProjectsbyScenario ..............................................................209

AppendixC.ApplicationofSolarData .....................................................................................221

Pleasecitethisreportasfollows:

Richard Piwko et. al. 2007. IntermittencyAnalysis Project:Appendix B: Impact of Intermittent

GenerationonOperationofCaliforniaPowerGrid.CaliforniaEnergyCommission,PIERRenewable

EnergyTechnologiesProgram.CEC5002007081APB.

8/21/2019 __NERC_wind

7/242

v

List of Figures

Figure1.FlowchartofIntermittencyAnalysisProject. ......................................................................14

Figure2.TimeScalesforGridPlanningandOperations...................................................................16

Figure3.AverageSystemwideDailyLoad,Wind,Solar,andNetLoadProfilesofJuly2003.....24

Figure4.AllSystemwideDailyLoad,Wind,andSolarProfilesforJuly2003. .............................. 25

Figure5.AllSystemwideDailySolarProfilesforJuly2003..............................................................25

Figure6.AverageSystemwideDailyLoad,Wind,Solar,andNetLoadProfilesofJanuary2002.

............................................................................................................................................................26

Figure7.AllSystemwideDailyLoadandWindProfilesforJanuary2002. ...................................27

Figure8.AllSystemwideDailySolarProfilesforJanuary2002. ......................................................27

Figure9.AllIndividualCaliforniaWindPlantProfilesforJuly21,2003........................................ 28

Figure10.AllIndividualTehachapiRegionWindPlantProfilesforJuly21,2003........................29

Figure11.Load,Wind,andSolarDurationCurvesfor2010XScenario..........................................30

Figure12.2010HourlyLoadandNetLoadDurationCurvesfor3Years. ..................................... 31

Figure13.DetailofLoadandNetLoadDurationCurvesfor2010XScenario. ..............................32

Figure14.2010XWindProductionandPenetrationDurationCurves. ...........................................33

Figure15.2010XSolarProductionandPenetrationDurationCurves. ............................................34

Figure16.2006and2010HourlyAverageWindPenetrationbyDecile..........................................35

Figure17.2006and2010HourlyAverageSolarPenetrationbyDecile........................................... 36

Figure18.2020HourlyLoadandNetLoadDurationCurves. ......................................................... 37

Figure19.2020HourlyAverageWindandSolarPenetrationbyDecile.........................................38

Figure20.HourlyProfilesand1HourDeltasforanExampleJuly2002Day................................40

Figure21.2010XHourlyLoadandNetLoadDeltaStockChartbyDecile.....................................44

Figure22.2006and2010StandardDeviationofHourlyLoadandNetLoadDeltas....................45

Figure23.2010XAverageHourlyWindandSolarPenetrationbyHourofDay...........................46

Figure24.2010XHourlyLoadandNetLoadDeltaStockChartbyHourofDay. ........................47

Figure25.2010XJulyHourlyLoadandNetLoadDeltaStockChartbyHourofDay. ................47

Figure26.2010XJanuaryHourlyLoadandNetLoadDeltasStockChartbyHourofDay.........48

8/21/2019 __NERC_wind

8/242

vi

Figure27.2010X3HourLoadandNetLoadDeltasStockChartbyHouroftheDay. ................49

Figure28.2010XJanuary3HourLoadandNetLoadDeltasStockChartbyHouroftheDay...50

Figure29.20103HourPositiveLoadandNetLoadDeltaDurationCurvesfor2004..................51

Figure30.20103HourNegativeWindDeltaDurationCurvesfor2004StudyYear....................52

Figure31.20101HourNegativeLoadandNetLoadDeltaDurationCurvesfor2004................53

Figure32.20101HourPositiveWindDeltaDurationCurvesfor2004StudyYear......................54

Figure33.2020HourlyLoadandNetLoadDeltasStockChartbyDecile......................................55

Figure34.2020JanuaryHourlyLoadandNetLoadDeltasStockChartbyHourofDay............56

Figure35.2010LoadDurationCurveswith3HourPeriodsofInterestIdentified.......................58

Figure36.1MinuteProfilesDuring3HourPeriodofExampleJuly2003Day.............................59

Figure

37.

Example

for

Load

Following

and

Regulation

Metric

Definition....................................60Figure38.LoadFollowingRequirementforJuly2003Example3HourPeriod............................61

Figure39.RegulationRequirementforJuly2003Example3HourPeriod..................................... 62

Figure40.2010X5MinuteDeltaDurationCurvesforLightLoad(10thDecile). ..........................63

Figure41.2010X1MinuteDeltaDurationCurvesforLightLoad(10thDecile). ..........................64

Figure42.2010XSubHourlyDeltaWindDurationCurvesforLightLoad(10thDecile)............65

Figure43.2010Load,Wind,andSolarForecastsandActualsDuringanExampleJulyWeek. ..68

Figure44.2010Load,Wind,Solar,andNetLoadForecastErrorsDuringExampleJulyWeek..69

Figure45.2010XLoad,Wind,Solar,andNetLoadDayAheadForecastErrorDurationCurves.

............................................................................................................................................................70

Figure46.2006LoadandNetLoadDayAheadForecastErrorStockChartbyDecile. ...............74

Figure47.2010XLoadandNetLoadDayAheadForecastErrorStockChartbyDecile..............75

Figure48.2010XLoad,Wind,Solar,andNetLoadHourAheadForecastErrorDurationCurves.

............................................................................................................................................................76

Figure

49.

2010X

Load

and

Net

Load

Hour

Ahead

Forecast

Error

Stock

Chart

by

Decile............77

Figure50.SpotPriceDurationCurvefor2002Shapes(#1). ..............................................................83




8/21/2019 __NERC_wind

9/242

vii


Figure55.SpotPriceDurationCurvefor2003Shapes.......................................................................86

Figure56.SpotPriceDurationCurvefor2004Shapes.......................................................................86

Figure57.SpotPriceDurationCurvefor2004Shapes(zoom). ........................................................ 87

Figure58.WECCOperatingCostReductionsDuetoRenewables($M).........................................87

Figure59.WECCOperatingCostReductionsDuetoRenewables($/MWh). ................................88

Figure60.LoadPaymentReductionsDuetoRenewables($M). ...................................................... 89

Figure61.LoadPaymentReductionsDuetoRenewables($/MWh)................................................89

Figure62.NonRenewableGeneratorRevenueReductionsDuetoRenewables($M). ................90

Figure63.NonRenewableGeneratorRevenueReductionsDuetoRenewables($/MWh)..........90

Figure

64.

Impact

of

Intermittent

Forecast

on

Spot

Price

(2010T).....................................................92Figure65.ImpactofIntermittentForecastonSpotPrice(2010X).....................................................92

Figure66.ImpactofIntermittentForecastonSpotPrice(2010Xand2020)....................................93

Figure67.TotalOperatingCostImpactofIntermittentForecasting................................................94

Figure68.CaliforniaGeneratorRevenueReductionsbyType(2010T)...........................................95

Figure69.WECCGeneratorRevenueReductionsbyType(2010T). ...............................................95

Figure70.CaliforniaEnergyChangeDuetoRenewables(2010T). ..................................................96

Figure71.WECCEnergyChangeDuetoRenewables(2010T).........................................................96

Figure72.AnnualDurationCurvesCaliforniaRenewableGeneration. ...................................... 97

Figure73.AnnualDurationCurvesCaliforniaWindandSolarGeneration...............................98

Figure74.AnnualDurationCurvesCaliforniaNuclear,SteamandGasTurbines. ................... 98

Figure75.AnnualDurationCurvesCaliforniaHydroGeneration............................................... 99

Figure76.OneWeekChangeinCaliforniaHydroOperation(2010T). .........................................100

Figure77.AnnualChangeinCaliforniaHydroOperation(2010Tand2010X)............................100

Figure78.AnnualChangeinWECCHydroOperation(2010T)..................................................... 101

Figure79.AnnualHistogramofHydroShift(2010T). .....................................................................101

Figure80.AnnualDurationCurves CaliforniaPumpedStorageHydroOperation.................102

Figure81.AnnualDurationCurves CaliforniaCombinedCycleGeneration............................102

Figure82.AnnualDurationCurves CaliforniaImports. ...............................................................103

8/21/2019 __NERC_wind

10/242

viii

Figure83.CaliforniaHistoricalHydroOperation SampleMayWeek........................................104

Figure84.CaliforniaHistoricalHydroOperationMay. ...............................................................104

Figure85.CaliforniaHistoricalHydroOperationJune. ............................................................... 105

Figure86.CaliforniaHistoricalHydroOperationJuly. ................................................................ 105

Figure87.CaliforniaHydroHistoricalMonthlyDurationCurves. ...............................................106

Figure88.2005CEMSDataDeltaEnergyCenter...........................................................................107

Figure89.2005CEMSDataHaynesGeneratingStation. ..............................................................107

Figure90.2005CEMSDataValleyGeneratingStation. ................................................................108

Figure91.CommitmentWeekofMay10th. ..................................................................................... 109

Figure92.Dispatch WeekofMay10th. .............................................................................................109

Figure

93.

Ramp

Rate

and

Range

Capability

Week

of

May

10th

. ..................................................110Figure94.RampRateDownCapabilityWeekofMay10th...........................................................110

Figure95.RampRateDownCapacityWithoutConventionalHydro WeekofMay10th.........111

Figure96.RampRateDownCapabilityVersusCaliforniaLoad(2010X). ....................................111

Figure97.RangeDownCapabilityVersusCaliforniaLoad(2010X). ............................................112

Figure98.RampRateUpCapabilityVersusCaliforniaLoad(2010X). .........................................112

Figure99.RangeUpCapabilityVersusCaliforniaLoad(2010X)...................................................113

Figure100.AnnualRampRateDownCapability.............................................................................113

Figure101.AnnualRampRateDownCapability(zoom). ..............................................................114

Figure102.OperationofHelmsPumpedStorageHydro(2010X)..................................................114

Figure103.HistoricalHydroDailyMinimum,Maximum,andRange,2006. .............................. 115

Figure104.DailyRangeOfHydroOperation,Summer2004and2006. .......................................116

Figure105.ConstrainedVersusBaseHydroforaSampleMayWeek(2010T). ...........................116

Figure106.AnnualDurationCurveCaliforniaHydroGeneration(2010T)...............................117

Figure107.RampDownCapacityWithConstrainedHydro,2010T. ............................................117

Figure108.RampDownCapacityWithConstrainedHydro,2010T(zoom)................................118

Figure 109. Annual Duration Curve California PSH Operation with Constrained Hydro

(2010T). ............................................................................................................................................119

Figure110.ComparisonofHelmsOperation,Summer2004and2006. ........................................119

8/21/2019 __NERC_wind

11/242

ix

Figure111.SampleWeekofPumpingOperation,January2006. ...................................................120

Figure112.HistoricalPumpingOperation,2006. .............................................................................120

Figure113.CaliforniaEmissionReductionsDuetoRenewables(2010T). ....................................121

Figure114.WECCEmissionReductionsDuetorenewables(2010T). ...........................................121

Figure115.CaliforniaEmissionReductionsDuetoNewWindandSolarGeneration(2010T).122

Figure116.WECCEmissionReductionsDuetoNewWindandSolarGeneration(2010T)......122

Figure117.TransmissionFlowDurationCurvesPath15:SouthofLosBanos.........................123

Figure118.TransmissionFlowDurationCurvesPath21:ArizonatoCalifornia .....................123

Figure119.TransmissionFlowDurationCurvePath46:WestofColoradoRiver...................124

Figure 120. Transmission Flow Duration Curves Total SCIT (Southern California Import

Transmission). ................................................................................................................................124

Figure121.AnnualDurationCurvePath66:COI(2010T). ..........................................................125

Figure122.Path66:COIFlowsforOneWeekinMay(2010T). ......................................................125

Figure123.AnnualDurationCurveforHourlyFlowChangesonPath66:COI(2010T)...........126

Figure124.TotalCaliforniaLoadDuringtheJulyMorningQSSStudyPeriod...........................134

Figure125.TotalCaliforniaWindGenerationDuringtheJulyMorningQSSStudyPeriod. .... 135

Figure126.TotalCaliforniaSolarGenerationDuringtheJulyMorningQSSStudyPeriod. ..... 135

Figure

127.

Maneuverability

Variables

During

the

July

Morning

QSS

Study

Period..................137Figure128.QSSPerformanceVariablesDuringtheJulyMorningQSSStudyPeriod. ...............138

Figure129.EconomicDispatchUnitChangeDuringtheJulyMorningQSSStudyPeriod. ...... 139

Figure 130. Impact of Intermittent Variability on Regulation Duty During July QSS Study

Period...............................................................................................................................................140

Figure131.ImpactofIntermittentVariabilityonEconomicDispatchandLoadFollowingDuty

DuringJulyQSSStudyPeriod. ....................................................................................................140

Figure132.TotalCaliforniaLoadDuringtheMayNightQSSStudyPeriod. .............................. 141

Figure133.TotalCaliforniaWindGenerationDuringtheMayNightQSSStudyPeriod..........142

Figure134.ManeuverabilityVariablesDuringtheMayNightQSSStudyPeriod. ..................... 143

Figure135.PerformanceVariablesDuringtheMayNightQSSStudyPeriod.............................144

Figure136.ManeuverabilityVariablesforaMayNightwithMoreCombinedCyclePlants...145

Figure137.PerformanceVariablesforaMayNightwithMoreCombinedCyclePlants..........146

8/21/2019 __NERC_wind

12/242

x

Figure138.ImpactofWindVariabilityonRegulationDutyDuringMayQSSStudyPeriod....147

Figure139.ImpactofWindVariabilityonEconomicDispatchandLoadFollowingDutyDuring

MayQSSStudyPeriod. ................................................................................................................. 147

Figure140.TemporaryCurtailmentofWindGeneration................................................................149

Figure141.ImpactofTemporaryCurtailmentofWindGenerationonEconomicDispatchand

LoadFollowingDutyDuringMayQSSStudyPeriod. ...........................................................149

Figure142.ImpactofTemporaryCurtailmentofWindGenerationonRegulationDutyDuring

MayQSSStudyPeriod. ................................................................................................................. 150

Figure143.ModifiedLoadProfileWithoutLargeSwitchingEvents.............................................151

Figure144.SelectedCAISO1MinuteLoadDatafromMay2002,2003,and2004. ..................... 151

Figure145.ManeuverabilityVariablesforaMayNightwiththeModifiedLoadProfile..........152

Figure

146.

Performance

Variables

for

a

May

Night

with

the

Modified

Load

Profile.................153Figure147.TotalCaliforniaLoadDuringtheJuneEveningQSSStudyPeriod...........................154

Figure148.TotalCaliforniaWindGenerationDuringtheJuneEveningQSSStudyPeriod. .... 154

Figure149.TotalCaliforniaSolarGenerationDuringtheJuneEveningQSSStudyPeriod. ..... 155

Figure150.ManeuverabilityVariablesDuringtheJuneEveningQSSStudyPeriod..................156

Figure151.PerformanceVariablesDuringtheJuneEveningQSSStudyPeriod.........................156

Figure 152. Impact of Including Hourly Wind Forecast on Regulation Duty During theJune

Evening

QSS

Study

Period. ..........................................................................................................158

Figure 153. Impact of Including Hourly Wind Forecast on Economic Dispatch and Load

FollowingDuringtheJuneEveningQSSStudyPeriod. ..........................................................158

Figure154.TemporaryCapwithRampUpRateLimitonWindGeneration. ............................160

Figure155.ComparisonofRegulationDuringtheJuneEveningQSSStudyPeriod. .................160

Figure156.ComparisonofEconomicDispatchandLoadFollowingDuring theJuneEvening

QSSStudyPeriod. .......................................................................................................................... 161

Figure157.ScheduleandLoadFollowingforaSampleDayofCaliforniaOperation................164

Figure158.HistoricalInterchangeforaSampleJulyWeek. ...........................................................165

Figure159.InstantaneousRangeofInterchangeforSampleJulyWeek. ...................................... 165

Figure160.RegulationandInterchangeforaSampleDayofCaliforniaOperation. ..................166

Figure161.HistoricalACEData..........................................................................................................167

Figure162.PseudoACEfromQSSSimulations. ..............................................................................168

8/21/2019 __NERC_wind

13/242

xi

Figure163.HistoricalLoadandProcuredRegulationDatafor2003. ............................................169

Figure164.StandardDeviationsofHourlyDeltas. .......................................................................... 171

Figure165.AnnualStandardDeviationChanges. ............................................................................ 172

Figure166.StandardDeviationsforOneHourDeltasatLightLoad...........................................173

Figure167.LightLoadStandardDeviationChanges.......................................................................174

Figure 168. Comparison of Historical Forecast and Actual Load and Simulated DayAhead

ForecastandActualWind. ...........................................................................................................176

Figure 169. 2010X Load and Net Load DayAhead Forecast Error Ignoring Wind and Solar

ForecastStockChartbyDecile.....................................................................................................177

Figure170.IntermittentGenerationImpactonHydroOperation..................................................178

Figure171.CommittedGenerationRangeandMaximumHourlyNetLoadChange................179

Figure172.CommittedGenerationRampRateCapabilityandExpectedLoadFollowingDuty...........................................................................................................................................................180

Figure 173. Expanded View of Committed Generation Ramp Rate Capability and Expected

LoadFollowingDuty.....................................................................................................................180

Figure174.ImpactofWindVariabilitywithPumpsinLoadProfile............................................. 181

Figure175.ImpactofWindVariabilityWithoutPumpsinLoadProfile ...................................... 182

Figure176.MayNight:ImpactofWindVariabilitywithPumpSteps..........................................184

Figure

177.

May

Night:

Impact

of

Wind

Variability

Without

Pump

Steps ...................................184

Figure178.ExampleConcentratingSolarProjectProfileforaMayDay. .....................................222

Figure179.ExampleStirlingSolarProjectProfileforaMayDay. .................................................223

Figure180.ExamplePVSolarZIPCodeProfilesforaMayDay....................................................224

Figure181.ComparisonofOriginal15MinuteDataandFinalProfilewith1MinuteVariability.

..........................................................................................................................................................226

Figure182.IrradiationDataUsedasSourceof1MinuteVariabilityinExample. ...................... 226

8/21/2019 __NERC_wind

14/242

xii

List of Tables

Table1.RenewableGenerationMixforFourStudyScenarios. ........................................................ 18

Table2.WindandSolarGenerationinCalifornia. .............................................................................19

Table3.LocationsofWindandSolarResourcesforScenario2010T. ..............................................19

Table4.LocationsofWindandSolarResourcesforScenario2010X. ..............................................19

Table5.2006HourlyLoadStatistics(MW)..........................................................................................41

Table6.2006HourlyNetLoadandIntermittentRenewableStatistics(MWor%).......................41

Table7.2010HourlyLoadStatistics(MW)..........................................................................................42

Table8.2010THourlyNetLoadandIntermittentRenewableStatistics(MWor%).....................42

Table9.2010XHourlyNetLoadandIntermittentRenewableStatistics(MWor%). ...................43

Table10.2020HourlyLoadStatistics(MW)........................................................................................57

Table11.2020HourlyNetLoadandIntermittentRenewableStatistics(MWor%). .................... 57

Table12.StatisticsonLoadFollowingRequirementforJuly2003Example3HourPeriod.......61

Table13.StatisticsonRegulationRequirementforJuly2003Example3HourPeriod.................62

Table14.Summaryof2006and2010FullYearStatisticalAnalysis. ............................................... 66

Table15.Summaryof2006and2010LightLoad(10thDecile)StatisticalAnalysis........................66

Table16.Summaryof2010and2020HourlyStatisticalAnalysis. ...................................................67

Table17.2006HourlyLoadForecastStatistics(MW). .......................................................................70

Table18.2006HourlyNetLoad,Wind,andSolarForecastStatistics(MW). .................................71

Table19.2010HourlyLoadForecastStatistics(MW). .......................................................................71

Table20.2010THourlyNetLoad,Wind,andSolarForecastStatistics(MW)................................72

Table21.2010XHourlyNetLoad,Wind,andSolarForecastStatistics(MW)................................72

Table22.2010XDayAheadForecastErrorStandardDeviation. .....................................................73

Table23.2010XDayAheadForecastErrorEnergy............................................................................ 73

Table24.2010XHourAheadForecastErrorStandardDeviation. ...................................................76

Table25.2010XHourAheadForecastErrorEnergy. ......................................................................... 76

Table26.ProductionSimulationScenarioDescription. .....................................................................82

8/21/2019 __NERC_wind

15/242

xiii

Table27.AverageVariableOperatingCostReductionsperMWhofRenewableEnergy(2010T).

..........................................................................................................................................................126

Table28.AverageLoadPaymentReductionsperMWhofRenewableEnergy(2010T).............127

Table 29. Average NonRenewable Generator Revenue Reduction per MWh of Renewable

Energy

(2010T)................................................................................................................................127 Table30.AnnualLoadPaymentReductionsfromIntermittentGeneration(2010T). .................127

Table31.AverageAnnualEmissionReductions inWECCperMWhofRenewableGeneration

(2010T). ............................................................................................................................................127

Table32.CharacteristicsofQSSStudyPeriods. ................................................................................130

Table33.WeightedAverageRampRateDatabyUnitType...........................................................132

Table34.MinimumGenerationOutputLevelbyUnitType. .........................................................132

Table

35.

Total

and

Light

Load

Change

in

Flexibility

Requirements. ............................................170Table36.TotalVariabilityfromStatisticalAnalysis. ........................................................................174

Table37. LoadFollowingStatisticsofQSSPumpandWindSensitivityCases..........................182

Table38.LoadFollowingStatisticsofLightLoadConditionsforPumpandWindSensitivity182

Table39.RegulationStatisticsofQSSPumpandWindSensitivityCases ....................................184

Table40.RegulationStatisticsofLightLoadConditionsforPumpandWindSensitivity ........ 184

Table41.WindProjectsIncludedin2006StudyScenario. ..............................................................203

Table42.IncrementalWindProjectsAddedfor2010TStudyScenario......................................... 204

Table43.IncrementalWindProjectsAddedfor2010XStudyScenario.........................................205

Table44.IncrementalWindProjectsAddedfor2020StudyScenario. ..........................................207

Table45.SolarProjectsIncludedin2006StudyScenario. ...............................................................209

Table46.IncrementalSolarProjectsAddedfor2010TStudyScenario..........................................209

Table47.IncrementalSolarProjectsAddedfor2010XStudyScenario. ........................................213

Table48.IncrementalSolarProjectsAddedfor2020StudyScenario. ...........................................213

Table49.StandardDeviationofthe15MinuteVariabilityintheCaliforniaPVData................225

Table50.StandardDeviationofthe15MinuteVariabilityintheGolden,CO,IrradiationData.

..........................................................................................................................................................225

8/21/2019 __NERC_wind

16/242

xiv

8/21/2019 __NERC_wind

17/242

1

Executive Summary

Californiahasoneofthemostdiverseelectricitysupplysystemsinthenationwithalarge

potentialtogenerateelectricityfromrenewablesources,suchaswind,geothermal,biomass,

hydroelectricandsolar.Withprogressiverenewablepolicies,thechallengefacingthestatewill

be

how

best

to

integrate

and

manage

renewable

energy

resources

with

traditional

generation

whileensuringareliableelectricitysystem.

Study Overview

TheIntermittencyAnalysisProjectwastailoredtopresentastatewideperspectiveofthe

transmissioninfrastructureandservicesneededtoaccommodatetherenewablepenetration

levelsdefinedinthestatesrenewableenergypolicy.TheIntermittencyAnalysisProjectwas

technicalandwasintendedtoprovidea2020perspectiveonpotentialoperationalneedsand

impactstomeetfuturegrowthanddemand.

ThisreportdocumentsthelaststageofthemultistageIntermittencyAnalysisProject.

Precedingstagesincluded:

Evaluationofpast,present,andfuturewindturbinetechnologies,andtheireffecton

transmissionsystemoperationandperformance,byBEWEngineering,Inc.

Assessmentofworldwideexperiencewithintegratinglargepenetrationsofwind

energy,byKevinPorterofExeterAssociates,Inc.

Developmentoffuturerenewableenergyscenariosandevaluationoftheeffectson

transmissionreliability,byDavisPowerConsultants.

ThefuturerenewablegenerationscenariosdevelopedbyDavisPowerConsultantswerecritical

inputstotheanalysisdocumentedinthisreport.DataprovidedfromDavisPowerConsultants

included:

Detailedlistsofindividualrenewablegeneratingplantsandtheirsite/ratingforeach

scenariostudied,consistentwithCaliforniasRenewablesPortfolioStandardgoals

andlocationsofrenewableresources,and

Powerflowdatasetswithconventionalgeneration,renewablegeneration,and

transmissionsystembuildoutsforeachscenario,consistentwiththeprojected

Californiapeakloadlevel.

TheIntermittencyAnalysisProjectconsideredfourtypesofrenewablegenerationtomeet

Californiasrenewableenergygoals:wind,solar,geothermal,andbiomass.Windandsolar

generationareintermittent,astheirenergysourcesarenotdispatchable:

Thepowerproducedbyawindplantvariesasafunctionofwindspeed.

Thepowerproducedbysolargenerationvariesastheintensityofthesunlight.

Geothermalandbiomassresourcesaredispatchableand,therefore,arenotintermittent

generation.

8/21/2019 __NERC_wind

18/242

2

Fourscenarioswereanalyzed,asfollows:

2006BaseCase

o Existing2006transmissionsystemwithexistingmixofgeneration,including

2,100megawatts(MW)ofwindand330MWofsolar.

2010TehachapiCasewith20percentrenewableenergy(designated2010T)

o 7,500MWwindand1,900MWsolarinCalifornia.

o Includes4,200MWofnewandexistingwindgenerationatTehachapi,withnew

500kilovolt(kV)transmissiontosupportit.

2010AcceleratedCasewith33percentrenewableenergy(designated2010X)


o Assumesinteriminfrastructurewithmostofthe2020intermittentrenewablegeneration.

2020Casewith33percentrenewableenergy


GeneralElectricEnergyConsultingevaluatedtheeffectofintermittentgeneration(windand

solar)ontheoperationoftheCaliforniapowergrid.Theobjectiveswere:

EvaluateCaliforniagridoperationwithincreasinglevelsofintermittentgeneration,

uptotherenewablepolicylevelsofwindandsolarandusingthefourscenarios

developedforthatpurpose.

Identifyandquantifysystemperformanceandanyoperationalproblems(for

example,loadfollowing,regulation,operationduringlowloadperiods).

Identifyandevaluatepossiblemitigationmethods.

Theevaluationcoveredtimescalesinvolvedingridoperationandincludedthefollowing

specifictypesofanalysisforeachscenario:

Statisticalanalysisofvariabilityduetosystemload,aswellaswindandsolar

generationovertimeframes(hourly,5minute,1minute).

ProductioncostsimulationsoftheCaliforniapowergridandtheWesternElectricity

CoordinatingCouncil,usingtheMultiAreaProductionSimulationprogram,toevaluatehourbyhourgridoperationfor3yearswithdifferentwindandload

profiles.

Quasisteadystatesimulations,usingPositiveSequenceLoadFlowprogram,to

evaluateminutebyminutetimesequencedpowerflowsfortheentireWestern

ElectricityCoordinatingCouncilgridoverseveralhours,toquantifygrid

performancetrendsandtoinvestigatepotentialmitigationmeasures.

8/21/2019 __NERC_wind

19/242

3

Theeffectofwindandsolarforecastingingridoperationsandunitcommitmentwerealso

evaluated.

Conclusions

Twoscenarios(2010Tand2020)representedstepsonanexpectedtrajectorytomeetCalifornias

renewablegenerationgoal.Theartificiallyaccelerated2010Xscenariowasdevelopedto

increasesystemstressandrepresentsthemostchallengingstudycondition.However,the

conclusionsandrecommendationspresentedinthissectionapplytoallscenarios,notjustthe

mostchallenging.Theyareintendedtoenableconsistent,sustainedrenewablegrowththrough

2020.

The2010Xscenarioexaminedatotalof19,800MWofrenewablesinCalifornia,including

12,500MWofwindgeneration,2,600MWofsolar,1,000MWofbiomass,and3,700MWof

geothermal.Thisscenariorepresentsastressedconditiondesignedtotestthesystemwithmore

renewablesthanprojectedfor2010.

ThislevelofrenewablegenerationcanbesuccessfullyintegratedintotheCaliforniagridprovidedappropriateinfrastructure,technology,andpoliciesareinplace.Specifically,this

successfulintegrationwillrequire:

Investmentintransmission,generation,andoperationsinfrastructuretosupportthe

renewableadditions.

Appropriatechangesinoperationspractice,policy,andmarketstructure.

Cooperationamongallparticipants,CaliforniaIndependentSystemOperator

(CaliforniaISO),investorownedutilities,renewablegenerationdevelopersand

owners,nonFederalEnergyRegulatoryCommissionjurisdictionalpowersuppliers,

andregulatorybodies.

Recommendations

ThestudyscenariosrepresentstagesalongatrajectorytomeetCaliforniasrenewable

generationgoal.Thefollowingrecommendationsareasetoftargets,actions,andpolicies

designedtoensuresuccessfulintegrationofsignificantlevelsofintermittentrenewable

generationthrough2020.Theimplementationoftheserecommendationsshouldproceedwith

therenewablegenerationgrowth.Suchevolutionaryimprovementswillallowsecureand

economicintegrationatallstagesalongtherenewablegenerationgrowthtrajectory.

Thechallengeofaccommodatingsubstantialintermittentrenewablegenerationisincremental

tothechallengeofservingexistingandnewload.Longtermplanningmustalwaysconsider

requirementsforgenerationandtransmissionandstrikeanappropriatebalancebetweenthe

two.Further,newconsiderationsspecifictorenewabletechnologiesmustbeincluded.Thus,the

planningprocessmustconsiderthreemajorsystemcomponents:

Generation

Transmission

8/21/2019 __NERC_wind

20/242

4

RenewableTechnology

Therecommendationspresentedbelowaregroupedaccordingly.

Generation Resource Adequacy

TheCaliforniaEnergyCommission,CaliforniaPublicUtilitiesCommission,andCaliforniaISO

haveongoingprocessestoprovidethegenerationinfrastructurenecessarytomaintainreliableoperation.Theadditionofbothintermittentandnondispatchablerenewableresourcestothe

Californiagridincreasestherequirementforgenerationresourceflexibility.Itisessentialthat

thisrequirementforflexibilitybeincludedintheoverallassessmentandplanningforresource

adequacy.Itisrecommendedthatspecificattributesofgenerationflexibilitybeinventoried,

maintained,andincreased.Wherepossible,quantitativetargetsaresuggested;othersmaybe

adoptedascircumstancesandunderstandingchanges.Toavoidrepetition,specificpolicyand

technologyrecommendationsaregroupedwiththemostrelevantperformanceissue.However,

manyrecommendationscouldapplytoabroaderrangeofperformancecategories.Further,

noneoftherecommendationsareeitherselfsufficientormutuallyexclusive.Anappropriate

combination

of

recommendations

will

be

most

successful.

MinimumLoadOperation.TheCaliforniagridshouldtargetacombinationofinstategenerating

resourcesandpowerexchangecapability/agreementswithneighboringsystemsthatallow

operationdowntoaminimumnetload(loadminuswindminussolar)intherangeof

18,000MWto20,000MW.Thesetargetswillmeetthelongterm(2020)needsofthesystemand

allowforoperationwithminimalcurtailmentofintermittentrenewables.

MinimumTurndown.Generatingresourceswithlowerminimumpoweroutputlevels

providegreaterflexibilityandallowsuccessfuloperationatminimumload.New

generatingresourcesshouldbeencouragedand/orrequiredtohavethiscapability;

existinggenerationshouldbeencouragedand/orrequiredtoupgradetheircapability.

Acomparisonoftheloadandnetload(loadwindsolar)forthevariousscenarios

showsthatminimumsarelesswiththeintermittentgenerationonthesystem.The

minimumsystemturndowncapabilitywilldeterminetheamountofrenewable

generationcurtailmentthatisnecessary.Aminimumof20,000MWisexpectedtoresult

incurtailmentduringafewhundredhoursperyearfortheexpectedgrowthtrajectory.

DiurnalStart/Stop.Anotherwaytomeetminimumloadistoincreasetheamountof

generationthatiscapableofreliablediurnalcycling.Thiswillbenefitthesystemby

allowingthecommitmentofunitsthatareeconomicatpeakandshoulderloads,

withoutrequiringtheirnoneconomicoperationatlightload.

LoadParticipation.Activeparticipationbylargeloads,especiallypumps,isanotherway

toassureadequateflexibility.ThepumpscontrolledbyCaliforniaDepartmentofWater

Resourcesarealreadyparticipantsintheenergymarket,butadditionaltypesof

participationandcooperationcouldincreaseoverallsystemflexibility.Forexample,

additionalinvestmentinpumps,controls,orotherloadinfrastructuretotakeadvantage

oflightloadenergypricingcouldbebotheconomicandeffective[8].

8/21/2019 __NERC_wind

21/242

5

Californiashouldexploreothermeanstoencourageloadshiftingtowardlightload

conditions.Variousloadshiftingandstoragetechnologies,suchascoldstorage(for

example.forbuildingcoolingorinletaircoolingforgaspeakinggeneration)hold

promiseandmayprovetobeeconomic.Arrangementsthatgivethegridoperator

controloverloadsforacontractualconsiderationorratereductionwillbemore

attractiveaspenetrationofintermittentrenewablesincreases.

PumpedStorageHydro.Useofpumpedstoragehydrofacilitieswasshowntoincreasefor

thescenariosexamined.Theinfrastructureandpolicynecessarytoallowthebestuseof

existingpumpedstoragehydrowithinCaliforniashouldbeenhanced.Additional

pumpedstoragehydrocapabilitycouldalsoenhancesystemschedulingflexibilityand

willlikelyaidotherflexibilityattributesdiscussedbelow.Thisisparticularlytruewhen

conventionalhydroflexibilityislow,duetounusuallyhighrunoffconditions.

HourlyScheduleFlexibility.TheCaliforniagridshouldtargetacombinationofinstategenerating

resourcesthatprovideaminimumlevelofschedulingflexibility.Theanticipatedloadgrowth

to2020willdrivetheoverallsystemflexibilityneedsfromthepresentlevelofabout4,300megawattsperhour(MW/hr)toabout6,000MW/hr.Theadditionalvariabilityand

uncertaintyassociatedwithintermittentrenewableswillincreasetheamplitudeofsustained

loadramps(bothupanddown),andthefrequencyofgenerationstartsandstops.Forthe

expectedrenewablesgrowthtrajectory(2010T,2020),theoverallhourlyflexibilityrequirement

isexpectedtobeabout130MW/hrgreaterthanthatrequiredforloadalone.Underthe

artificiallyacceleratedrenewableexpansionofthe2010Xscenario,thatincrementalrequirement

isabout400MW/hr.

Duringlightloadconditions,totalrequirementsaresmaller,buttherelativeimpactof

intermittentrenewablesislarger.Theanticipatedloadgrowthto2020willdrivethelightload

systemflexibilityneedsfromthepresentlevelofabout2,000MW/hruptoabout3,000MW/hr.

Fortheexpectedrenewablesgrowthtrajectory(2010T,2020),thehourlylightloadflexibility

requirementisexpectedtobeabout1,000MW/hrgreaterthanthatrequiredforloadalone.

HydroScheduling.Conventionalhydroelectricgenerationplaysakeyroleinlightload

scheduleflexibilityaswellasloadfollowingandregulation.Economicoperationwillbe

enhancedbyhighhydroflexibility.Existingflexibilityshouldbemaintainedatleast,

andinvestmentstoincreasemaneuverabilityshouldbeconsidered.Adocumented

inventoryofcapabilityisimportant.Californiashouldperiodicallyexaminetheamount

andtypeofhydroconstraints,andevaluateinvestmentsorcontractualmechanismsfor

costeffectivereliefofthoseconstraints.

FasterStart/Stop.Uncertaintiesinforecastscreateasomewhatdifferentflexibility

requirement.Evenwithstateoftheartwindforecasting,bothdayaheadandhour

aheadnetloadforecastuncertaintieswillincreaseduetointermittentrenewables.With

anincreasedriskofanactualnetloadsignificantlydifferentfromtheforecastnetload,

shortnoticestart/stopcapabilityduringdailyoperationwillbeanimportantpartofthe

redispatchneededtobalancegenerationandload.TheCaliforniagridshouldtarget

8/21/2019 __NERC_wind

22/242

6

sufficientinstategeneratingresourcecapabilitytomeetdayaheadforecasterrorsinthe

rangeof5,000MWofgenerationcapacityandhouraheadforecasterrorsintherange

of2,000MWofgenerationcapacity.Overall,thisrepresentsaboutdoublethepresent

levelofdayaheadloadforecasterrorandabout20percentmorethanthepresenthour

aheadloadforecasterror.

Duringlighterloadperiods,thenetloadforecasterrormaybethreetimestheload

aloneforecasterrorinthedayaheadforecast.Thetargetsrecommendedabovewillalso

besufficientforlightloadconditions.

MultiHourScheduleFlexibility.Flexibilitytargetsshouldalsoaddressperiodsofsustainedload

increasesanddecreases.TherecommendedtargetsarefortheCaliforniagridtohaveenough

resourcestomeetamaximummorningloadincreaseof12,000MWoverthreehoursanda

maximumeveningloaddecreaseof14,000MWoverthreehours.Thisrepresentsanincreaseof

about1,000MWoverthecapabilityneededtomeettheloadalone.

LoadFollowingCapability.TheCaliforniagridshouldtargetacombinationofinstategenerating

resourcesthatprovideaminimumlevelofgenerationrampingcapability,bothupanddown.

Onaverage,thesystemshouldmaintainontheorderof+/130MW/minuteforaminimumof5

minutes.Thisisabouta10MW/minuteincreaseovertherequirementduetoloadalone.

Duringlightloadconditions,approximately70MW/minuteofdownloadfollowingcapability

arerequired.Uploadfollowingrequirementsarelower.Theloadfollowingcapabilityshould

besubjecttoeconomicdispatchfromthesystemoperators.Loadfollowingdutyshouldnotbe

shiftedtounitsprovidingregulation.

Import/ExportScheduling.TheCaliforniagridshouldrecognizethateconomic

incorporationofsubstantialinstaterenewableswillinevitablyinvolvesignificant

displacementofimportedenergy.Regulatoryandcontractualarrangementsforimports

andexportsshouldbestructuredsuchthatthevalueofschedulingflexibilityis

recognized,allowed,andappropriatelycompensated.Inparticular,Californiashould

allowschedulechangestooccurmorefrequentlyandattimesotherthanonthehour.

RegulationCapability.TheCaliforniagridshouldtargetacombinationofinstategenerating

resourcesthatprovideaminimumlevelofregulationcapability.TheCaliforniaISOcurrently

procuresregulationintherangeof300MWto600MW.Theprocuredamountvaries

substantiallyoverallloadlevels.Theimpactofintermittentrenewablesonregulation(20MW)

isconsiderablylessthanthenormalvariabilityintheamountprocured.However,regulation

resourceswillcontinuetobeimportant.Therefore,theCaliforniagridshouldatleastmaintain

thecurrentlevelofregulationcapability.Thislevelofregulationshouldallowthestateto

continuetosatisfytheirregulatoryobligationsforinterchangeandfrequencycontrol,suchas

theNorthAmericanElectricReliabilityCouncilControlPerformanceStandard2compliance

shouldbecontinuallyscrutinizedasintermittentrenewablesareaddedtothegridtorefine

regulationrequirementsandprocurement.

8/21/2019 __NERC_wind

23/242

7

RegulationTechnologies.Californiashouldconsiderusingtechnologiesbeyond

conventionalgenerationtoprovideregulation.Theearlierdiscussionaboutload

participationinscheduleflexibilityapplieshereaswell.Functionalrequirementsfor

loadstoprovideregulationaredifferentfromthoseforgeneration.Givenasuitable

regulatoryandmarketstructure,however,itislikelythatothertechnologiesand

participantswillemergetoprovidetherequiredservices.Examplesincludesometypes

ofstoragetechnology,suchasvariablespeedpumpedhydroandthelatestflywheel

energystoragesystems.Policyandmarketstructureshouldencouragediversityof

participantsinprovidingancillaryservices,andtechnicalspecificationsforperformance

shouldbesufficientlyflexibletoallowtheintroductionofnewtechnologies.

NonTechnicalResourceAdequacyConsiderations.Theprecedingrecommendationswereaimedat

securingthetechnicalcapabilitiesnecessaryforsuccessfulintegrationofintermittent

renewables.Thefollowingitemsaddresspolicyandcommercialconsiderations.

MarketDesign.Itmustberecognizedthatwhileoperationalflexibilityisvaluabletothe

grid,itcurrentlyholdslittleattractionforpowersuppliers.Deeperturnback,morerapidcyclingandloadfollowing,andmorefrequentstartsandstopsallimpose

significantcostsandrevenuereductionsonthesuppliers.Marketandregulatory

structuresmustrecognizethevalueoftheseflexibilityfeatures.Policychangesmay

includeacombinationofexpandedancillaryservicesmarkets,incentives,and

mandates.

ContractualObligations.Muchoftheanalysispresentedinthisreportisbasedonthe

presumptionthatthegridisoperatedrationallythatis,theavailablegeneration

resourcesareusedasefficientlyandeconomicallyaspossible.Theanalysisdidnot

includehistoricalconstraints,suchaslongtermcontractualobligations,thatforcethe

systemtorunlessefficientlythanpossible.Newcontractsunderconsideration,existing

longtermcontractsupforrenewal,orindeedanyexistingcontractsthatcouldbe

renegotiatedshouldbereviewedwithalloftheprecedingresourceadequacy

recommendationsinmind.TheCaliforniagridmustmaintainoperationalflexibility,

andtodoso,itmusthavenotonlythephysicalresourcesnecessary,butalsothe

businessandcontractualarrangementsnecessarytoenabletherationaluseofthose

physicalresources.

Retirements.Generatingplantretirementsthatwerefirmlyscheduledwhenthe

databaseswereassembledwereincorporatedintothisstudy.However,increased

competitionfromnewresources,renewableorotherwise,willtendtopushmarginally

profitablegeneratingresourcesoutofbusiness.Suchspeculative,economicretirements

werenotconsideredinthestudy.Successfulimplementationoftherecommendations

abovewillensurethatresourceswiththenecessaryflexibilityareavailable.Inaddition,

itisrecommendedthatretirementsbeprojected,monitored,andevaluatedduringthe

resourceplanningprocess.

8/21/2019 __NERC_wind

24/242

8

Inventory.Duringthisstudy,itwasnotedthatgeneratorcharacteristicsandcapabilities

(forexample,minimumturndown,rampratecapability)werenotalwaysknownwith

sufficientdetailorcertainty.Somedegreeofuncertaintyisinevitable.However,with

theincreasedneedforresourceflexibility,Californiashouldimplementaprogramto

measure,verify,andcataloguetheflexibilitycharacteristicsofthegenerationresources.

AprogramsimilartotheWesternElectricityCoordinatingCouncilgeneratordynamic

testingmightprovesuitable.

Transmission Infrastructure

TheadditionofthousandsofMWofnewgenerationofanyvarietywillrequireexpansionof

thetransmissionsystem.Thisstudyincludedtheadditionofenoughbulktransmission

necessaryforconnectionofthenewrenewablestothegridasdeterminedanddocumentedby

DavisPowerConsultants[6].However,itwasnotadetailedtransmissionstudyandisnota

substituteforone.Policiesmustrecognizethatlocalproblemsmightdevelop,andenablethe

necessarytransmissionadditions.Practiceandpolicythatcorrectproblemsandstrikeabalance

betweeninfrastructureinvestmentandcongestionarenecessary.Toanappreciableextent,this

observationholdsforalltransmissionplanningandallgenerationadditions.Californiacan

economicallybenefitfromchangesinplanningandoperationofthetransmissioninfrastructure

byrecognizingthelocationalandvariablenatureofintermittentrenewables.Thefollowing

recommendationsarespecifictotheseneeds.

ExistingConstraints.Californiahasexistinginfrastructurethatcontributessubstantiallytothe

secureandeconomicoperationofthegridwithhighlevelsofintermittentrenewables.Insome

circumstances,theuseofthatinfrastructureforsystemwidebenefitisconstrainedbylocal

transmissionlimitations.OneexampleofsuchaconstraintistheoccasionalinabilityofHelms

pumpedstoragehydrotoreachfullpumpingpower.Planningandpolicyshouldrecognizeand

enable

correction

of

such

local

limitations.

RatingCriteria.Windgenerationisvariable,andthespatialdifferencesbetweenplants

substantiallyeffectsthecoincidentproductionofpowerfromthoseplants.Clearly,awindplant

willreachratedoutputformanyhoursperyear.Thus,normalplanningcriteriarequires

sufficientcapability,suchasthermalrating,onthetransmissioninterconnectiondedicatedto

thatplanttoaccommodateratedpoweroutput.

However,asmorewindplantsvieforaccesstospecifictransmissioncorridors,itwillbe

increasinglyunlikelythatallwindplantswillsimultaneouslyreachtheirmaximumoutput.

Notethatinthreeyearsofdata,allwindplantsinthisstudyneversimultaneouslyreached

maximumoutput.Andthe12,500MWofwindgenerationexceeded10,000MWofproduction

lessthan1percentofthetime.Thus,transmissionplanningtoaccommodatemultiplewind

plantsshouldconsidertheirspatialdifferencesandthestatisticalexpectationofsimultaneous

highpoweroutputlevels.Plantsclosetogetherwillgenerallyrequiretransmissioncapability

equivalenttotheaggregateratingoftheplants.Plantsthatarefartherapartmayrequireless

transmissioncapability.Hence,itisnotnecessarytoguaranteesufficientratingonthebulk

transmissioninfrastructuretoaccommodateallwindprojectsatfulloutput.Existingcriteria

shouldbesufficienttoprovidethisplanningflexibility.

8/21/2019 __NERC_wind

25/242

9

Technology.Policyshouldrewardinvestmentintechnologytomaximizeuseoftransmission

infrastructureforrenewables.Suchpoliciesshouldrecognizethatwindgenerationisa

relativelypoorresourceforcapacityandthatcreativeuseoftechnologymayoptimizeuseof

transmission.Regulatoryandcontractualpracticeshouldallowtechnologiessuchasrealtime

lineratings,controlsthatmanageoutputfromintermittentrenewableresources,localshort

termforecasting,andothernonstandardapproachestobalancerenewableenergydelivery

withtransmissioninfrastructurecosts.

Renewable Generation Technology, Policy, and Practice

Withsignificantlevelsofintermittentrenewablegeneration,operationmaybechallengingat

extremelylightloadlevels,underaconstrainedtransmissiongrid,orwithhighwindvolatility.

Undertheseconditions,renewablegenerationmustparticipateinoverallgridcontrol.The

followingrecommendationsarespecifictorenewabletechnologyandareaimedatassuringthat

intermittentrenewablesplayanactiveandpositiveroleinthesecureandeconomicoperationof

thegrid.

Curtailment.Undertherareoccasionsofcoincidentminimumload,highwindgeneration,andlowconventionalhydroflexibility,itmustbepossibletocurtailintermittentrenewables.The

gridoperatorshouldhavetheabilitytoordersuchareductioninproduction.Regulatoryand

contractualarrangementsforintermittentrenewablesshouldbestructuredsuchthat

curtailmentsarerecognized,allowed,andappropriatelycompensated.Rampratecontrols

couldalsobeconsidered.

AncillaryServices.Intermittentrenewablesmaybeabletoprovideancillaryservicesthatare

bothvaluableandeconomicundersomeoperatingconditions.Forexample,windgeneration

canprovidefrequencyregulation.Suchfunctionalityisarequirementinsomeregions[10].

Regulatoryandcontractualarrangementsforintermittentrenewablesshouldbestructuredsuch

thatprovidingsuchservicesarerecognized,allowed,andappropriatelycompensated.

Forecasting.SuccessfulandeconomicoperationoftheCaliforniagridrequireswindandsolar

forecasting.Thisstudyverifiedsubstantialbenefitsfromtheuseofstateoftheartdayahead

forecastingintheunitcommitmentprocess.Substantialbenefitsareexpectedforimprovements

inbothlongerterm(multiday)andshortterm(hoursandminutesahead)forecasting.

Investmentandpolicymustencouragedevelopmentofhighfidelityintermittentrenewable

forecastingforallintermittentrenewablegenerationinthestate.

Monitoring.Thewindproductionprofilesusedinthisstudyarebasedonhistoricalweather

dataandsophisticatedcomputermodels.Recordeddatafromrealoperatingexperiencewillbe

invaluableinrefiningoperatingpractice,performance,andflexibilityrequirements.Timesynchronizedproductionandmeteorologicaldatafrommanyplantswillprovidevalidationor

correctionofthetrendsandresultspredictedbythisstudy.Theywillshowthebenefitsand

limitationsofspatialdifferences,mesoscalemodeling,andvariouswindplantcontrols.Itis

recommendedthatCaliforniacontinueandexpand,asnecessary,programstomonitor,analyze,

anddisseminateperformanceinformationregardinggridoperationsandplanningfor

intermittentrenewables.

8/21/2019 __NERC_wind

26/242

10

ThetargetedlevelsofrenewablegenerationcanbesuccessfullyintegratedintotheCalifornia

gridprovidedappropriateinfrastructure,technology,andpoliciesareinplace.

8/21/2019 __NERC_wind

27/242

11

1.0 Introduction

Californiahasoneofthemostdiverseelectricitysupplysystemsinthenationwithalarge

potentialtogenerateelectricityfromrenewablesources,suchaswind,geothermal,biomass,

hydroelectricandsolar.WithprogressiverenewablepoliciesasintheRenewablesPortfolio

Standard

(RPS)

and

state

Energy

Action

Plan

[1],

the

challenge

facing

the

state

will

be

how

best

tointegrateandmanagerenewableenergyresourceswithtraditionalgenerationwhileensuring

areliableelectricitysystem.

1.1. Challenges

Withpolicytargetsof20%renewableenergyby2010and33%by2020,afewofthemain

challengesfacingthestateinclude:

Buildingsufficienttransmissioninfrastructuretosupportandsustainthe

developmentenvisionedfor2020

Balancingtheneedtointegrateincreasinglevelsofrenewableenergywhile

minimizingadverseimpactsonthesurroundingenvironment

Developingtoolswiththeindustrytoproperlyintegratevariablerenewable

resourcesincludingwindandsolar

1.2. Background

TheIntermittencyAnalysisProject(IAP)soughttoaddressthefollowingquestions:

Whataretheimpactsofincreasingrenewableenergyprojectsonsystemreliability

anddispatchability,withaparticularfocusonwindandsolarenergy?

Whatwillthefuturesystemlooklikeandwherewilltheresourcescomefrom?

Howwillthefuturegridneedtorespond?Willitrespondbymarketstructure,

services,ortechnologies?

TheIAPwastailoredtopresentastatewideperspectiveofthetransmissioninfrastructureand

servicesneededtoaccommodatetherenewablepenetrationlevelsdefinedinthestates

renewableenergypolicy.TheIAPwastechnicalinnatureandwasintendedtoprovideayear

2020perspectiveonpotentialoperationalneedsandimpactstomeetfuturegrowthand

demand.Asaresult,certainassumptionsweremadeontechnologyavailability,system

conditionsandconstraints,aswellasmarketconstraints.

Inthisproject,powerflowandproductioncostmodelingwereconductedtoestablishthe

operationalbaselineoftheCaliforniagridasof2006andtodeveloptherenewableresource

mixesforthe2010and2020scenarios.Renewableportfoliomixesaswellasthetransmission

neededtointerconnecttheresourceswereevaluatedinthescenariosbasedonatransmission

benefitcriteria.ThemodelingbuiltandexpandedonpreviousCaliforniaEnergyCommission

(EnergyCommission)fundedtransmissionstudiesthatfocusedonconnectingstatewide

renewableresourcepotentialandtheassociatedtransmissionconsiderations.

8/21/2019 __NERC_wind

28/242

12

ThisprojectbuiltuponworkthatwascompletedfortheEnergyCommissionaspartofthe2005

IntegratedEnergyPolicyReport(IEPR)process[2].Moreinformationmaybefoundrelatedto

IEPRontheCommissionwebsite(www.energy.ca.gov).TheIAPeffortleveragedwork

conductedbytheCaliforniaWindEnergyCollaborative(CWEC)[3],theConsortiumfor

ElectricReliabilityTechnologySolutions(CERTS)[4],andtheStrategicValueAnalysis(SVA)

workbyDavisPowerConsultants(DPC).UndertheSVAproject,PublicInterestEnergy

Research(PIER)andDPCassessedtheavailabilityofrenewableresourcesanddefinedan

approachthatminimizestransmissioninfrastructurechangesandmaximizesbenefitsfor

integratingrenewablesontotheCaliforniagridbyavoidingcongestion.Availabilityofinter

stateandintrastaterenewableresourcesandtransmissionrequirementswerealsomodeled

usingtheSVAapproachtoalleviate,oratleastminimize,transmissionconstraints[5].

1.3. Intermit tent Generation Defin ition

TheIAPconsideredfourtypesofrenewablegenerationtomeetCaliforniasrenewableenergy

goals;wind,solar,geothermal,andbiomass.Windandsolargenerationareintermittent,as

theirenergysourcesarenotdispatchable:

Thepowerproducedbyawindplantvariesasafunctionofwindspeed

Thepowerproducedbysolargenerationvariesastheintensityofthesunlight.

Geothermalandbiomassresourcesaredispatchable,andthereforearenotintermittent

generation.

1.4. Overview of Project Objectives, Tasks and Participants

ThisreportdocumentsthelaststageofthemultistageIAP.Precedingstagesincluded:

Evaluationofpast,present,andfuturewindturbinetechnologies,andtheirimpact

ontransmissionsystemoperationandperformance,byBEWEngineering,Inc.

Assessmentofworldwideexperiencewithintegratinglargepenetrationsofwind

energy,byKevinPorterofExeterAssociates,Inc.

DevelopmentoffuturerenewableenergyscenariosconsistentwithCaliforniasRPS,

andevaluationoftheimpactsontransmissionreliability,byDavisPower

Consultants(DPC).

ThefuturerenewablegenerationscenariosdevelopedbyDPCwerecriticalinputstothe

analysisdocumentedinthisreport.Figure1isaflowchartshowingthemajortasksthat

assessedgridimpactsandmitigationmethodsforintermittency,aswellasthetasksthat

producedthescenariosanddatanecessaryforthatanalysis.DPCassessedthepotentialforfuturerenewableresources(wind,solar,geothermal,biomass)anddevelopedaseriesof

scenarioswithincreasinglevelsofrenewablegeneration,consistentwiththegoalsofthe

CaliforniaRPS.AlloftherenewablegenerationwaslocatedinsideCalifornia.TheDPCteam

alsodevelopedcorrespondingtransmissionexpansionplansforeachrenewablegeneration

scenario.

8/21/2019 __NERC_wind

29/242

13

Thus,theresultsoftheDPCtaskincludedthefollowingforeachscenario:

Detailedlistofindividualrenewablegeneratingplantsandtheirsite/rating,

consistentwithCaliforniasRPSgoalsandlocationsofrenewableresources,and

Powerflowdatasetswithconventionalgeneration,renewablegeneration,and

transmissionsystembuildoutsconsistentwiththeprojectedCaliforniapeakloadlevel.

Thescenariosare:

2006BaseCase

o Existing2006transmissionsystemwithexistingmixofgeneration,including

2,100megawatts(MW)ofwindand330MWofsolar.

2010TehachapiCasewith20%renewableenergy(designated2010T)


o Includes4,200MWofnewandexistingwindgenerationatTehachapi,withnew

500kilovolts(kV)transmissiontosupportit.

2010AcceleratedCasewith33%renewableenergy(designated2010X)


o Assumesinteriminfrastructurewithmostofthe2020intermittentrenewable

generation.

2020Casewith33%renewableenergy


CompleteresultsofthisportionoftheIAParedocumentedinthereportIntermittencyImpacts

ofWindandSolarResourcesonTransmissionReliability,byDavisPowerConsultants[6].

8/21/2019 __NERC_wind

30/242

14

Powerflow Data and

Renewable Generation Mix

for 4 Study Scenarios

(from DPC)

Wind Power Profiles(from AWST)

Solar Power Profiles

(from multiple sources)

Load Profiles and

Historical Operation Data

(from CAISO)

Analysis of Impacts

on

Grid Operations

Statistical Analysis

Quasi-Steady-State

Simulations

Production Cost

Simulations

Conclusions and

Recommendations

Evaluation of Potential

Mitigation Methods

Renewable Resource

Potential and Availability

Assessment

(by DPC)

Transmission

Assessment

Development of Study Scenarios(by DPC Team)

Analysi s of Grid Impacts and Mi tigat ion Methods(by GE Energy Consu lting Team)

Figure 1. Flowchart o f Intermittency Analysis Project.

Note:AWST=AWSTruewind,LLC.;CAISO=CaliforniaIndependentSystemOperator;

GEEnergy=GeneralElectricEnergyConsulting.

GeneralElectricEnergyConsulting,(GE)evaluatedtheimpactofintermittentgeneration(wind

andsolar)ontheoperationoftheCaliforniapowergrid.Theobjectiveswere:

EvaluateCaliforniagridoperationwithincreasinglevelsofintermittentgeneration,

uptotherenewablepolicylevelsofwindandsolarandusingthefourscenarios

developedforthatpurpose.

Identifyandquantifysystemperformanceandanyoperationalproblems(e.g.,load

following,regulation,operationduringlowloadperiods).

Identifyandevaluatepossiblemitigationmethods.

Theevaluationcoveredmultipletimescalesinvolvedingridoperation,asillustratedinFigure

2,andincludedthefollowingspecifictypesofanalysisforeachscenario:

Statisticalanalysisofvariabilityduetosystemload,aswellaswindandsolar

generationovermultipletimeframes(hourly,5minute,1minute).

8/21/2019 __NERC_wind

31/242

15

ProductioncostsimulationsoftheCaliforniapowergridandtheWesternElectricity

CoordinatingCouncil(WECC),usingGeneralElectricsMultiAreaProduction

Simulation(GEMAPSTM)program,toevaluatehourbyhourgridoperationfor3

yearswithdifferentwindandloadprofiles.

Quasisteadystatesimulations,usingPositiveSequenceLoadFlow(PSLF)program,

toevaluateminutebyminutetimesequencedpowerflowsfortheentireWECCgrid

overseveralhours,toquantifygridperformancetrendsandtoinvestigatepotential

mitigationmeasures.

Theimpactofwindandsolarforecastingingridoperationsandunitcommitmentwerealso

evaluated.

Thisreportpresentstheresultsofthatanalysis,aswellasconclusionsandrecommendations

drawnfromtheresults.

1.5. Participants

Inconductingthisproject,GEEnergyConsultingcollaboratedwithseveralotherorganizationsonthefollowingessentialtasks:

AWSTrueWindwindprofiledataforexistingandfuturewindgenerationsites[7]

RumlaproductioncostmodeldatafortheCaliforniapowergridandWECC.

CaliforniaIndependentSystemOperator(CaliforniaISO)loadprofilesand

historicaloperationdatafortheCaliforniapowergrid.

Solardatawasobtainedfrommultiplesources,includingCaliforniaISO,the

UniversityofCaliforniaatDavis,theNationalRenewableEnergyLaboratory

(NREL),StirlingEnergySystems,theCaliforniaPublicUtilitiesCommission(CPUC)

SelfGenerationIncentiveProgram,andAtmosphericResearchScienceCenterattheStateUniversityofNewYorkatAlbany.

GEEnergyConsultinggratefullyacknowledgesthevaluablecontributionsofallofthese

organizations.Thisprojectcouldnothavebeenperformedwithoutthem.

8/21/2019 __NERC_wind

32/242

16

U n i t C o m m i t m e n tan d

Day-AheadS chedu l i ng

Load Fo l l ow i ng(5 Minu te D ispatch)

F r equency and

Tie-L ine Regu la t i on(AGC)

Day-ahead andMul t i -Day

Fo r ecas t i ng

Faster(seconds)

TimeFrame

Slower(Y

ears)

Plann ing and

Opera t ion ProcessT e c h n o l o g y

Issues

H our - A headFo r ecas t i ng

a n dP lant Ac t i ve Pow erM aneuve r ing and

M anagem en t

R esou r ce and

Capac i t y P lann ing

(Rel iabi l i ty)

Unit Dispatch

0

100

200

300

400

500

600

700

0 2000 4000 6000 8000

Hour

MW

Real -T ime andA u to n o m o u s Pro tec t io n

and C on t r o l Func t i ons(AGC, LVR T, PSS,Govern or , V -Reg, e t c . )

Capac i t y Va luat i on(UCAP, ICAP)

an dLong - Te r m Load

G r ow t h Fo r ecas t ing

2001 Average Load vs Average Wind

0

5,000

10,000

15,000

20,000

25,000

30,000

1 6 11 16 21

Hour

NYISOLoad(MW)

0

200

400

600

800

1,000

1,200

1,400

1,600

WindOutput(MW)

J u ly lo ad A u g u s t l o ad Se p te m b e r lo ad

J u ly w in d A u g u s t w in d Se p te m b e r w in d

0

50 0

1 0 0 0

1 5 0 0

2 0 0 0

2 5 0 0

3 0 0 0

1 6 1 1 2 1

M i n u t e s

MW

S ep tem be r M or ni ng A u gu s t Mo rn in g M ay Ev e nin g O ct ob er Ev e nin g A pr il A f te rn oo n

1 Year

1 Day

3 Hours

10 Minutes

Figure 2. Time Scales for Grid Planning and Operations.

UCAP=uniformcapacity,ICAP=installedcapacity,AGC=automatedgeneratorcontrol,

LVRT=lowvoltageridethrough,PSS=powersystemstabilizer,VReg=voltageregulation

8/21/2019 __NERC_wind

33/242

17

2.0 Study Approach

Theoverallstudyapproachisoutlinedinthissection.Thestudyscenarios,typesofanalysis,

dataprovided,andterminologyarealldescribedbelow.

2.1. Study ScenariosTherenewablegenerationmixforeachofthefourstudyscenariosissummarizedinTable1.

Thevariousscenarioscanbedescribedintermsofincreasinglevelsofrenewablegeneration

penetration.Butthedefinitionofpenetrationcanbeconfusing.ManyRenewablePortfolio

Standards(RPS)usepenetrationtodescribethepercentofenergytobeprovidedbyallofthe

renewablegeneration,includingwind,solar,geothermal,biomassandsometimeshydroelectric.

TheenergytargetsdiscussedintheIAPfallintothiscategorywith20%penetrationby2010

and33%penetrationby2020.Theenergydefinitionisimportantbecauseitisameasureof

theamountoffossilfuelgenerationthatcanbedisplaced.However,intheanalysisof

intermittentgenerationthetermpenetrationisoftenusedtodescribetheratioofthenameplate

capacityofintermittentgeneration(windandsolar)dividedbythepeakloadofthesystem.Thisis

becausetheimpactonoperationsisoftenafunctionoftheintermittentrenewablepoweroutput

relativetothesystemload.Bothdefinitionsareimportantandbothwillbeusedwithinthis

report.

In2006,theStateofCaliforniahadapeakloadof58,900MW,ofwhich48,900MWwaswithin

theCaliforniaISOoperatingarea.Therewas2,100MWofwindand330MWofsolar

generation,yielding4%intermittentgenerationpenetration(as%ofpeakload)statewideand

5%penetrationwithinCaliforniaISO.

Case2010Trepresentsafuturescenariofortheyear2010,withatotalof7,500MWofwindand

1,900MWofsolargenerationinCalifornia.Inthisscenario,theintermittentgenerationpenetrationis15%statewideand18%withintheCaliforniaISOoperatingarea.Thisscenario

includesover3,000MWofnewwindgenerationintheTehachapiregion,whichisconsistent

withexistingdevelopmentplans.Forthisstudy,theTehachapiregionwasbroadlydefinedto

includeallwindgenerationinregion8(fordetailsseetheAWSTruewindreport,[7]).

Case2020representsafuturescenarioforyear2020with33%renewableenergy,consistentwith

theCaliforniaRPSgoal.Itincludes12,700MWofwindand6,000MWofsolargeneration,

yieldinganintermittentpenetrationof25%inCaliforniaand31%withinCaliforniaISO.

Case2010Xrepresentsanacceleratedscenariowhere33%renewableenergyisintegratedintoa

transmission

system

similar

to

what

is

anticipated

for

the

year

2010.

Although

this

scenario

is

notarealisticprojectionofrenewableintegrationforyear2010,itprovidesvaluableinsights

relativetotheimpactofintermittentgeneration.The2020scenarioincludesnumeroussystem

expansionassumptionstoaccommodateaprojectedpeakloadof74,300MW,includingnew

transmissionlinesandconventionalgeneratingresources.The2010Xscenario,withapeakload

of62,600MW,doesnotincludethoseextensivegenerationandtransmissionadditions.Assuch,

gridperformanceofthe2010Xscenariocanbedirectlycomparedwithscenarios2010Tand

2006.Theprimarydifferencesbetweenthesescenariosarethelevelsofintermittentgeneration.

8/21/2019 __NERC_wind

34/242

18

Similarcomparisonswiththe2020scenarioaremoredifficulttointerpret,sincedifferencesare

notlimitedtointermittentgeneration,butalsoincludesignificantdifferencesinconventional

generation,loadlevel,andtransmissionsysteminfrastructure.

Table 1. Renewable Generation Mix for Four Study Scenarios.

Scenario2006 2010T 2010X 2020

California Peak Load, MW 58670 64336 64336 80742

California Minimum Load, MW 22804 25006 25006 31383

California Load Factor, % 60% 60% 60% 60%

California ISO Peak Load, MW 48466 53147 53147 66700

California ISO Minimum Load, MW 19066 20908 20908 26239

California ISO Load Factor, % 61% 61% 61% 61%

Total Geothermal Capacity, MW 2,400 4,100 3,700 5,100

Total Biomass Capacity, MW 760 1,200 1,000 2,000

Total Solar Capacity, MW 330 1,900 2,600 6,000

Total Wind Capacity, MW 2,100 7,500 12,500 12,700Wind Capacity in Tehachapi Region, MW 760 4,200 5,800 5,800

CA Wind+Solar Capacity Penetration, % 4% 15% 23% 23%

California ISO Wind+Solar Capacity Penetration,% 5% 17% 26% 25%

California ISO Wind+Solar Energy, GWH 6201 26,111 43,255 49,933

California Wind+Solar Energy, GWH 6201 27,220 44,365 51,042

CA Wind+Solar Energy Penetration, % 2% 8% 13% 12%

California ISO Wind+Solar Energy Penetration, % 2% 9% 15% 14%

Notes: LoadFactor=(TotalEnergy)/(PeakLoadx8760hours)

CapacityPenetration=(Wind+SolarCapacity)/(PeakLoad)

EnergyPenetration=(Wind+SolarEnergy)/(PeakLoadxLoadFactorx8760hours)

Thewindandsolargenerationresourcesinthisstudyaredistributedamongnumeroussites

acrossCalifornia.Table2summarizesthenumbersofindividualwindandsolarsites

representedineachscenario.Forexample,the2010Tscenarioincludes12concentratingsolar

facilities,136photovoltaicgenerationsites,and98windgeneratingplants,40ofwhicharein

theTehachapiregion.The2020scenarioincludes43concentratingsolarfacilities,228

photovoltaicgenerationsites,and147windgeneratingplants.Detailedlistsofindividualwind

generationandsolargenerationsitesforeachscena

Date post:	07-Aug-2018
Category:	Documents
Upload:	raulbsu
View:	212 times
Download:	0 times

__NERC_wind

Documents