National
Transmission
NeedsStudy:
Supplemental
Material
October2023
UnitedStatesDepartmentofEnergy
Washington,DC20585
-1-
ExecutiveSummary
ThismaterialsupplementstheUnitedStatesDepartmentofEnergy’sNationalTransmission
NeedsStudy(NeedsStudy),publishedOctober2023.Materialhereprovidesadditional
context,methodology,anddataassociatedwithinformationintheNeedsStudy.This
documentisorganizedtomatchthesectionnumbersandheadersoftheNeedsStudywhen
appropriate;asaresult,sectionnumberingisnotsequential.
NationalTransmissionNeedsStudy:SupplementalInformation|Pageii
-2-
DepartmentofEnergy|October2023
NationalTransmissionPlanningStudy:
SupplementalMaterial
TableofContents
ExecutiveSummaryii
FindingsSummaryGraphicMethodology1
SectionIV.CurrentTransmissionNeedAssessmentthroughHistoricalData7
SectionIV.a.HistoricalTransmissionInvestments7
SectionIV.b.MarketPriceDi?erentials9
SectionV:CurrentandFutureNeedAssessmentandIdentificationofTransmissionBene?ts
throughReviewofExistingStudies13
AllStudiesIncludedinSectionV13
Co-locationofTransmissionCorridorsIsPossibleinSomeCases25
SectionVI.AnticipatedFutureNeedAssessmentthroughCapacityExpansionModeling33
SectionVI.a.IncludedStudiesandScenarios33
High-levelDescriptionofSixCapacityExpansionModelingStudies33
ModelingFeaturesofDi?erentStudies37
ScenarioCharacteristics:ExcludedSce