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  <xsd:element id="oesx_EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostNotYetRecognizedDueInFourYears" name="EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostNotYetRecognizedDueInFourYears" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="oesx_EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostNotYetRecognizedDueInThreeYears" name="EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostNotYetRecognizedDueInThreeYears" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="oesx_EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostNotYetRecognizedDueInTwoYears" name="EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostNotYetRecognizedDueInTwoYears" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="oesx_EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostNotYetRecognizedDueThereafter" name="EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostNotYetRecognizedDueThereafter" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="oesx_EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostNotYetRecognizedNextTwelveMonths" name="EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostNotYetRecognizedNextTwelveMonths" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="oesx_EmployeeServiceSharebasedCompensationNonvestedAwardsCompensationCostNotyetRecognizedAlternatePeriodforRecognition" name="EmployeeServiceSharebasedCompensationNonvestedAwardsCompensationCostNotyetRecognizedAlternatePeriodforRecognition" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_EmployeeStockPurchasePlanAllowedLoanAmountPercentageOfAnnualIncome" name="EmployeeStockPurchasePlanAllowedLoanAmountPercentageOfAnnualIncome" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="oesx_EmployeeStockPurchasePlanClosingMarketPriceOfSharesPurchased" name="EmployeeStockPurchasePlanClosingMarketPriceOfSharesPurchased" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_EmployeeStockPurchasePlanLoanIRSInterestRate" name="EmployeeStockPurchasePlanLoanIRSInterestRate" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_EmployeeStockPurchasePlanPurchasePriceToMarketPriceMatchingPercentage" name="EmployeeStockPurchasePlanPurchasePriceToMarketPriceMatchingPercentage" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="oesx_EmployeeStockPurchasePlansDebtStructureDirectLoanAmount" name="EmployeeStockPurchasePlansDebtStructureDirectLoanAmount" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="oesx_EmployeeStockPurchasePlansDebtStructureDirectLoanRepaymentAmount" name="EmployeeStockPurchasePlansDebtStructureDirectLoanRepaymentAmount" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="oesx_EmployeeStockPurchasePlansDebtStructureSharesIssued" name="EmployeeStockPurchasePlansDebtStructureSharesIssued" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_EmployeeStockPurchasePlansLoanMaximumOutstandingAmount" name="EmployeeStockPurchasePlansLoanMaximumOutstandingAmount" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="oesx_EmployeeStockPurchasePlansSharesAuthorized" name="EmployeeStockPurchasePlansSharesAuthorized" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="oesx_EnergyManagementMember" name="EnergyManagementMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_EngineeredSystemsMember" name="EngineeredSystemsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_EntitythatCurrentDirectorOwnsMinorityInterestandServesasBoardofDirectorsChairmanMember" name="EntitythatCurrentDirectorOwnsMinorityInterestandServesasBoardofDirectorsChairmanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_FairValueOfClosingCommonStockPrice" name="FairValueOfClosingCommonStockPrice" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="oesx_FinancingReceivableTypeAxis" name="FinancingReceivableTypeAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_FinancingReceivableTypeDomain" name="FinancingReceivableTypeDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_FiniteLivedandIndefiniteLivedIntangibleAssetsGross" name="FiniteLivedandIndefiniteLivedIntangibleAssetsGross" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="oesx_GoodwillImpairmentLossAndImpairmentOfRealEstate" name="GoodwillImpairmentLossAndImpairmentOfRealEstate" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_GreaterThanNinetyDaysMember" name="GreaterThanNinetyDaysMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_HarrisMember" name="HarrisMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_HarrisSellersNoteMember" name="HarrisSellersNoteMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_InventoryFinishedGoodsValuationReserves" name="InventoryFinishedGoodsValuationReserves" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="oesx_InventoryRawMaterialsandSuppliesValuationReserves" name="InventoryRawMaterialsandSuppliesValuationReserves" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="oesx_InventoryReserveLengthofTimeofInventoryUsageConsidered" name="InventoryReserveLengthofTimeofInventoryUsageConsidered" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_InventoryWorkinProcessValuationReserves" name="InventoryWorkinProcessValuationReserves" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="oesx_June2011OtaFinanceProgramMember" name="June2011OtaFinanceProgramMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_LessorLeasingArrangementsOperatingLeasesNumberofExtensionOptions" name="LessorLeasingArrangementsOperatingLeasesNumberofExtensionOptions" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_LimitedProductWarrantyTerm" name="LimitedProductWarrantyTerm" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_LineofCreditFacilityAdditionalBorrowingCapacity" name="LineofCreditFacilityAdditionalBorrowingCapacity" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="oesx_LineofCreditFacilityCovenantTermsMinimumIndebtednessRatio" name="LineofCreditFacilityCovenantTermsMinimumIndebtednessRatio" nillable="true" substitutionGroup="xbrli:item" type="xbrli:pureItemType" xbrli:periodType="instant" />
  <xsd:element id="oesx_LongTermReceivablesPolicyTextBlock" name="LongTermReceivablesPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_ManitowocManufacturingandDistributionFacilityMember" name="ManitowocManufacturingandDistributionFacilityMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_MaximumAmountLimitForEmployeeStockPurchasePlanPerEmployee" name="MaximumAmountLimitForEmployeeStockPurchasePlanPerEmployee" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="oesx_MinimumSubscriptionPercentage" name="MinimumSubscriptionPercentage" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_NonEmployeeDirectorMember" name="NonEmployeeDirectorMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_NoncashOrPartNoncashAcquisitionNoncashContingentConsiderationLiability" name="NoncashOrPartNoncashAcquisitionNoncashContingentConsiderationLiability" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="oesx_NoncashOrPartNoncashAcquisitionNoncashFinancialOrEquityInstrumentConsiderationIssued" name="NoncashOrPartNoncashAcquisitionNoncashFinancialOrEquityInstrumentConsiderationIssued" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_NotPastDueMember" name="NotPastDueMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_NumberOfSupportingIndividualOtaCustomerContracts" name="NumberOfSupportingIndividualOtaCustomerContracts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element id="oesx_NumberofFinancialInstitutions" name="NumberofFinancialInstitutions" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_NumberofLeaseAgreements" name="NumberofLeaseAgreements" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_October2011Member" name="October2011Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_OneToNinetyDaysMember" name="OneToNinetyDaysMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_OperatingLeasesMonthlyRentalPaymentsReceivable" name="OperatingLeasesMonthlyRentalPaymentsReceivable" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="oesx_OperatingLossCarryforwardsAssociatedWithExerciseOfNonQualifiedStockOptions" name="OperatingLossCarryforwardsAssociatedWithExerciseOfNonQualifiedStockOptions" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="oesx_OtherLongTermAssetsPolicyTextBlock" name="OtherLongTermAssetsPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_OtherLongTermDebtMember" name="OtherLongTermDebtMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_PastDueLeaseNetMember" name="PastDueLeaseNetMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_PaymentsToAcquirePropertyPlantAndEquipmentAndProductiveAssets" name="PaymentsToAcquirePropertyPlantAndEquipmentAndProductiveAssets" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="oesx_PeriodOfTimeStateIncomeTaxReturnsSubjectToExamination" name="PeriodOfTimeStateIncomeTaxReturnsSubjectToExamination" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_PeriodOfTimeWithoutInterestAccruingOrPrincipalPaymentsDue" name="PeriodOfTimeWithoutInterestAccruingOrPrincipalPaymentsDue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_PowerPurchaseAgreementProductRevenueRecognizableTerm" name="PowerPurchaseAgreementProductRevenueRecognizableTerm" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_PrepaidExpensesAndOtherCurrentAssetsPolicyTextBlock" name="PrepaidExpensesAndOtherCurrentAssetsPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_ProceedsfromExerciseofWarrantsandStockOptions" name="ProceedsfromExerciseofWarrantsandStockOptions" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="oesx_PropertyPlantandEquipmentImpairmentExpense" name="PropertyPlantandEquipmentImpairmentExpense" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_RangeEightMember" name="RangeEightMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_RangeFiveMember" name="RangeFiveMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_RangeFourMember" name="RangeFourMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_RangeSevenMember" name="RangeSevenMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_RangeSixMember" name="RangeSixMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_RangeThreeMember" name="RangeThreeMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_RangeTwoMember" name="RangeTwoMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_RelatedPartyTransactionsTextualAbstract" name="RelatedPartyTransactionsTextualAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_RightIssueSharePrice" name="RightIssueSharePrice" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="instant" />
  <xsd:element id="oesx_RightsDistributionDateTriggerNumberOfBusinessDaysAfterCommencementOrOfferOfAcquisition" name="RightsDistributionDateTriggerNumberOfBusinessDaysAfterCommencementOrOfferOfAcquisition" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_SaleLeasebackTransactionAreaofLeasedProperty" name="SaleLeasebackTransactionAreaofLeasedProperty" nillable="true" substitutionGroup="xbrli:item" type="num:areaItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_SaleLeasebackTransactionLeaseTerm" name="SaleLeasebackTransactionLeaseTerm" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_SalesTypeNetMember" name="SalesTypeNetMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_ScheduleOfWarrantsOutstandingRollforwardTableTextBlock" name="ScheduleOfWarrantsOutstandingRollforwardTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedForfeitureRate" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedForfeitureRate" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrantForfeited" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrantForfeited" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrantRestrictedShares" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrantRestrictedShares" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrantRollForward" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrantRollForward" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrantSharesIssuedToEmployee" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrantSharesIssuedToEmployee" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrantSharesIssuedToNonEmployee" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrantSharesIssuedToNonEmployee" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerSharePrice" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardPerSharePrice" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="instant" />
  <xsd:element id="oesx_ShareBasedCompensationArrangementsByShareBasedPaymentsAwardOptionMaximumLife" name="ShareBasedCompensationArrangementsByShareBasedPaymentsAwardOptionMaximumLife" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_SharePurchaseRightsRedemptionPrice" name="SharePurchaseRightsRedemptionPrice" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="instant" />
  <xsd:element id="oesx_SharebasedGoodsandNonemployeeServicesTransactionSecuritiesIssuedValuationPricePerShare" name="SharebasedGoodsandNonemployeeServicesTransactionSecuritiesIssuedValuationPricePerShare" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_SolarPowerSystemsCompletionPeriodMaximum" name="SolarPowerSystemsCompletionPeriodMaximum" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_SolarPowerSystemsCompletionPeriodMinimum" name="SolarPowerSystemsCompletionPeriodMinimum" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="oesx_StockIssuedDuringPeriodValueStockOptionsandWarrantsExercised" name="StockIssuedDuringPeriodValueStockOptionsandWarrantsExercised" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="oesx_StockholdersEquityReceivablefromShareholdersorAffiliatesforIssuanceofCapitalStock" name="StockholdersEquityReceivablefromShareholdersorAffiliatesforIssuanceofCapitalStock" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="oesx_Stockissuedduringperiodsharesstockoptionsandwarrantsexercised" name="Stockissuedduringperiodsharesstockoptionsandwarrantsexercised" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_SummaryOfIssuanceOfStockUnderEmployeeStockOwnershipPlanAbstract" name="SummaryOfIssuanceOfStockUnderEmployeeStockOwnershipPlanAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_SummaryOfSignificantAccountingPoliciesTextualAbstract" name="SummaryOfSignificantAccountingPoliciesTextualAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_SummaryofSignificantAccountingPoliciesLineItems" name="SummaryofSignificantAccountingPoliciesLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_SummaryofSignificantAccountingPoliciesTable" name="SummaryofSignificantAccountingPoliciesTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_TwoThousandFourStockAndIncentiveAndAwardPlanMember" name="TwoThousandFourStockAndIncentiveAndAwardPlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_U.S.MarketsMember" name="U.S.MarketsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="oesx_WellsFargoBankNationalAssociationMember" name="WellsFargoBankNationalAssociationMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
</xsd:schema>