ComputePresentValue Subroutine

private subroutine ComputePresentValue()

Arguments

None
Called By

Source Code

SUBROUTINE ComputePresentValue
          ! SUBROUTINE INFORMATION:
          !    AUTHOR         Jason Glazer of GARD Analytics, Inc.
          !    DATE WRITTEN   August 2010
          !    MODIFIED       na
          !    RE-ENGINEERED  na

          ! PURPOSE OF THIS SUBROUTINE:
          !    For each cashflow, compute the present value

          ! METHODOLOGY EMPLOYED:

          ! REFERENCES:
          ! na

          ! USE STATEMENTS:
IMPLICIT NONE    ! Enforce explicit typing of all variables in this routine


          ! SUBROUTINE ARGUMENT DEFINITIONS:
          ! na

          ! SUBROUTINE PARAMETER DEFINITIONS:
          ! na

          ! INTERFACE BLOCK SPECIFICATIONS
          ! na

          ! DERIVED TYPE DEFINITIONS
          ! na

          ! SUBROUTINE LOCAL VARIABLE DECLARATIONS:
REAL(r64) :: totalPV
INTEGER :: curCategory
INTEGER :: curResource
REAL(r64) :: curDiscountRate
INTEGER :: iCashFlow
INTEGER :: jYear
INTEGER :: kResource
INTEGER :: nUsePriceEsc
REAL(r64) :: effectiveYear

! identify how each cashflow should be treated
DO iCashFlow = 1, numCashFlow
  SELECT CASE (CashFlow(iCashFlow)%SourceKind)
    CASE (skResource)
      !only for real fuels purchased such as electricity, natural gas, etc..
      IF ((CashFlow(iCashFlow)%Resource) .GE. iRT_Electricity .AND. (CashFlow(iCashFlow)%Resource  .LE. iRT_ResidualOil)) THEN
        CashFlow(iCashFlow)%pvKind = pvkEnergy
      ELSE
        CashFlow(iCashFlow)%pvKind = pvkNonEnergy
      END IF
    CASE (skRecurring, skNonrecurring)
      IF (CashFlow(iCashFlow)%Category .EQ. costCatEnergy) THEN
        CashFlow(iCashFlow)%pvKind = pvkEnergy
      ELSE
        CashFlow(iCashFlow)%pvKind = pvkNonEnergy
      END IF
    CASE (skSum)
      CashFlow(iCashFlow)%pvKind = pvkNotComputed
    CASE DEFAULT
      CashFlow(iCashFlow)%pvKind = pvkNotComputed
  END SELECT
END DO
! compute the Single Present Value factors based on the discount rate
ALLOCATE(SPV(lengthStudyYears))
ALLOCATE(energySPV(NumOfResourceTypes,lengthStudyYears))
! Depending if using Constant or Current Dollar analysis
! use the appropriate discount rate
IF (inflationApproach .EQ. inflAppConstantDollar) THEN
  curDiscountRate = realDiscountRate
ELSEIF (inflationApproach .EQ. inflAppCurrentDollar) THEN
  curDiscountRate = nominalDiscountRate
END IF
!compute single present values based on real discount rates
DO jYear = 1, lengthStudyYears
  ! NIST 155 D.2.1.1 - Single Present Value (SPV) formula
  SELECT CASE (discountConvension)
    CASE (disConvBeginOfYear)
      effectiveYear = REAL(jYear,r64) - 1.0d0
    CASE (disConvMidYear)
      effectiveYear = REAL(jYear,r64) - 0.5d0
    CASE (disConvEndOfYear)
      effectiveYear = REAL(jYear,r64)
    CASE DEFAULT
  END SELECT
  SPV(jYear) = 1.0d0 / ((1.0d0 + curDiscountRate) ** effectiveYear)
END DO
!use SPV as default values for all energy types
DO jYear = 1, lengthStudyYears
  DO kResource = 1,NumOfResourceTypes
    energySPV(kResource,jYear) = SPV(jYear)
  END DO
END DO
!loop through the resources and if they match a UseEscalation use those values instead
DO nUsePriceEsc = 1,numUsePriceEscalation
  curResource = UsePriceEscalation(nUsePriceEsc)%resource - ResourceTypeInitialOffset
  IF ((curResource .GE. 1) .AND. (curResource .LT. NumOfResourceTypes)) THEN
    DO jYear = 1, lengthStudyYears
      !the following is based on UPV* formula from NIST 135 supplement but is for a single year
      SELECT CASE (discountConvension)
        CASE (disConvBeginOfYear)
          effectiveYear = REAL(jYear,r64) - 1.0d0
        CASE (disConvMidYear)
          effectiveYear = REAL(jYear,r64) - 0.5d0
        CASE (disConvEndOfYear)
          effectiveYear = REAL(jYear,r64)
        CASE DEFAULT
      END SELECT
      energySPV(curResource,jYear) = UsePriceEscalation(nUsePriceEsc)%Escalation(jYear) /   &
         ((1.0d0 + curDiscountRate) ** effectiveYear)
    END DO
  END IF
END DO
DO iCashFlow = 1, numCashFlow
  SELECT CASE (CashFlow(iCashFlow)%pvKind)
    CASE (pvkNonEnergy)
      totalPV = 0.0d0
      DO jYear = 1,lengthStudyYears
        CashFlow(iCashFlow)%yrPresVal(jYear) = CashFlow(iCashFlow)%yrAmount(jYear) * SPV(jYear)
        totalPV = totalPV + CashFlow(iCashFlow)%yrPresVal(jYear)
      END DO
      CashFlow(iCashFlow)%presentValue = totalPV
    CASE (pvkEnergy)
      curResource = CashFlow(iCashFlow)%Resource - ResourceTypeInitialOffset
      IF ((curResource .GE. 1) .AND. (curResource .LT. NumOfResourceTypes)) THEN
        totalPV = 0.0d0
        DO jYear = 1,lengthStudyYears
          CashFlow(iCashFlow)%yrPresVal(jYear) = CashFlow(iCashFlow)%yrAmount(jYear) * energySPV(curResource,jYear)
          totalPV = totalPV + CashFlow(iCashFlow)%yrPresVal(jYear)
        END DO
        CashFlow(iCashFlow)%presentValue = totalPV
      END IF
    CASE (pvkNotComputed)
      ! do nothing
  END SELECT
END DO
! sum by category
DO iCashFlow = countOfCostCat + 1, numCashFlow
  curCategory = CashFlow(iCashFlow)%Category
  IF ((curCategory .LE. countOfCostCat) .AND. (curCategory .GE. 1)) THEN
    CashFlow(curCategory)%presentValue = CashFlow(curCategory)%presentValue + CashFlow(iCashFlow)%presentValue
    DO jYear = 1,lengthStudyYears
      CashFlow(curCategory)%yrPresVal(jYear) = CashFlow(curCategory)%yrPresVal(jYear) + CashFlow(iCashFlow)%yrPresVal(jYear)
    END DO
  END IF
END DO
!create total categories
CashFlow(costCatTotEnergy)%presentValue = CashFlow(costCatEnergy)%presentValue
CashFlow(costCatTotOper)%presentValue = CashFlow(costCatMaintenance)%presentValue + &
                                            CashFlow(costCatRepair)%presentValue + &
                                            CashFlow(costCatOperation)%presentValue + &
                                            CashFlow(costCatReplacement)%presentValue + &
                                            CashFlow(costCatMinorOverhaul)%presentValue + &
                                            CashFlow(costCatMajorOverhaul)%presentValue + &
                                            CashFlow(costCatOtherOperational)%presentValue + &
                                            CashFlow(costCatWater)%presentValue + &
                                            CashFlow(costCatEnergy)%presentValue
CashFlow(costCatTotCaptl)%presentValue = CashFlow(costCatConstruction)%presentValue + &
                                            CashFlow(costCatSalvage)%presentValue + &
                                            CashFlow(costCatOtherCapital)%presentValue
CashFlow(costCatTotGrand)%presentValue = CashFlow(costCatTotOper)%presentValue + &
                                            CashFlow(costCatTotCaptl)%presentValue
DO jYear = 1,lengthStudyYears
  CashFlow(costCatTotEnergy)%yrPresVal(jYear) = CashFlow(costCatEnergy)%yrPresVal(jYear)
  CashFlow(costCatTotOper)%yrPresVal(jYear) = CashFlow(costCatMaintenance)%yrPresVal(jYear) + &
                                            CashFlow(costCatRepair)%yrPresVal(jYear) + &
                                            CashFlow(costCatOperation)%yrPresVal(jYear) + &
                                            CashFlow(costCatReplacement)%yrPresVal(jYear) + &
                                            CashFlow(costCatMinorOverhaul)%yrPresVal(jYear) + &
                                            CashFlow(costCatMajorOverhaul)%yrPresVal(jYear) + &
                                            CashFlow(costCatOtherOperational)%yrPresVal(jYear) + &
                                            CashFlow(costCatWater)%yrPresVal(jYear) + &
                                            CashFlow(costCatEnergy)%yrPresVal(jYear)
  CashFlow(costCatTotCaptl)%yrPresVal(jYear) = CashFlow(costCatConstruction)%yrPresVal(jYear) + &
                                            CashFlow(costCatSalvage)%yrPresVal(jYear) + &
                                            CashFlow(costCatOtherCapital)%yrPresVal(jYear)
  CashFlow(costCatTotGrand)%yrPresVal(jYear) = CashFlow(costCatTotOper)%yrPresVal(jYear) + &
                                            CashFlow(costCatTotCaptl)%yrPresVal(jYear)
END DO

END SUBROUTINE ComputePresentValue
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