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  <xs:element id="pwr_SeniorNotesDueAugust2027Member" abstract="true" name="SeniorNotesDueAugust2027Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_SeniorNotesDueAugust2028Member" abstract="true" name="SeniorNotesDueAugust2028Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_SeniorNotesDueOctober2030Member" abstract="true" name="SeniorNotesDueOctober2030Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_SeniorNotesDueJanuary2031Member" abstract="true" name="SeniorNotesDueJanuary2031Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_SeniorNotesDueJanuary2032Member" abstract="true" name="SeniorNotesDueJanuary2032Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_SeniorNotesDueAugust2034Member" abstract="true" name="SeniorNotesDueAugust2034Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_SeniorNotesDueAugust2035Member" abstract="true" name="SeniorNotesDueAugust2035Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_SeniorNotesDueOctober2041Member" abstract="true" name="SeniorNotesDueOctober2041Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_CommercialPaperProgramMember" abstract="true" name="CommercialPaperProgramMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_LeaseFinancingTransactionLiability" abstract="false" name="LeaseFinancingTransactionLiability" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pwr_TermLoanMember" abstract="true" name="TermLoanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_SeniorCreditFacilityMember" abstract="true" name="SeniorCreditFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_LettersOfCreditOutsideOfTheSeniorCreditFacilityMember" abstract="true" name="LettersOfCreditOutsideOfTheSeniorCreditFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_DebtWeightedAverageTerm" abstract="false" name="DebtWeightedAverageTerm" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="pwr_EffectiveIncomeTaxRateReconciliationIncreaseDecreaseInTaxBenefitShareBasedPaymentArrangementAmount" abstract="false" name="EffectiveIncomeTaxRateReconciliationIncreaseDecreaseInTaxBenefitShareBasedPaymentArrangementAmount" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pwr_A2023RepurchaseProgramMember" abstract="true" name="A2023RepurchaseProgramMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_RestrictedStockUnitsToBeSettledInCommonStockMember" abstract="true" name="RestrictedStockUnitsToBeSettledInCommonStockMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_PerformanceStockUnitsPSUsMember" abstract="true" name="PerformanceStockUnitsPSUsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_SilveradoWildfireMember" abstract="true" name="SilveradoWildfireMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_NumberOfSubsidiariesSubjectToLawsuits" abstract="false" name="NumberOfSubsidiariesSubjectToLawsuits" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="pwr_DamagedLandArea" abstract="false" name="DamagedLandArea" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:areaItemType"/>
  <xs:element id="pwr_PoleReplacementPeriodBeforeFire" abstract="false" name="PoleReplacementPeriodBeforeFire" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="pwr_CommitmentAndContingenciesTable" abstract="true" name="CommitmentAndContingenciesTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="pwr_EmployersLiabilityWorkersCompensationAutoLiabilityGeneralLiabilityAndGroupHealthCareClaimsMember" abstract="true" name="EmployersLiabilityWorkersCompensationAutoLiabilityGeneralLiabilityAndGroupHealthCareClaimsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_InsuranceTypeAxis" abstract="true" name="InsuranceTypeAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="pwr_InsuranceTypeDomain" abstract="true" name="InsuranceTypeDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_GeneralAndAutoLiabilityInsuranceMember" abstract="true" name="GeneralAndAutoLiabilityInsuranceMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_CommitmentAndContingenciesLineItems" abstract="true" name="CommitmentAndContingenciesLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="pwr_DeductibleAndAdditionalRetentionAmountForLiabilityProgramsMaximum" abstract="false" name="DeductibleAndAdditionalRetentionAmountForLiabilityProgramsMaximum" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pwr_DomesticJointVenturesMember" abstract="true" name="DomesticJointVenturesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_ForeignJointVenturesMember" abstract="true" name="ForeignJointVenturesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_InvestmentsInJointVenturesMember" abstract="true" name="InvestmentsInJointVenturesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_CaptiveInsuranceCompanyMember" abstract="true" name="CaptiveInsuranceCompanyMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_CashNotHeldByJointVenturesOrCaptiveInsuranceCompanyMember" abstract="true" name="CashNotHeldByJointVenturesOrCaptiveInsuranceCompanyMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_GoodwillAndIntangibleAssetsTable" abstract="true" name="GoodwillAndIntangibleAssetsTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="pwr_CurriculumMember" abstract="true" name="CurriculumMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pwr_GoodwillAndIntangibleAssetsLineItems" abstract="true" name="GoodwillAndIntangibleAssetsLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
</xs:schema>
