Dielectric Fluids Overview - Trade Association

1 CONFIDENTIAL. This document contains Trade secret information. Disclosure, use or reproduction outside Cargill or inside Cargill, to or by those employees who do not have a need to know is prohibited except as authorized by Cargill in ConferenceNovember 6th, Ester Dielectric Fluids OverviewAgenda Public Power DEED story History fluid comparison Natural Ester fluid Fire Safety Environmental Impact Longer life Industry Validation / Testing Key takeaways2 APPA's American Public Power AssociationDEED program-Conceives Natural Ester Revolution.

2 And Envirot FR3 3 Natural Ester transformer placed into service in 1997 by Waverly Power & Light- Iowa. Waverly P&L- Piloted field testing. Now nearly 1 million transformers use Natural Esters as part of their insulation system. A transformer containing the Envirotemp FR3 transformer fluid is pictured in the foreground. Photo courtesy of Waverly Light & Power Free Breathing DesignsSealed DesignsThermally Upgraded KraftNatural Esters188019001930196019902010 Common failure mode: mineral oil (sludge, a bi-product of oxidation) impacted heat transfer/dissipationDiagnostics put into practice2020 High temperature materials standardsCommon failure mode: shifted to solid insulation; constrained by operating temperatureCommon failure mode: solid insulation; operating temperature increased85oC AWR, 130oC HST55oC AWR, 95oC HST65oC AWR, 110oC HSTC ommon failure mode: solid insulation.

3 Operating temperature increasedTransformer history (1890-present)4 Mineral OilNatural Ester(FR3 fluid )Synthetic EsterSilicone OilBase FluidPetroleum OilVegetable OilHydrocarbonsPolydimethylsiloxanesDiag nostic CapabilityYesYesYesLessFire point160 C360 C310 C340 CBiodegradabilityLowUltimatelyReadilyNoB iobasedNoYesNoNoOxidationGoodAcceptable( non-free breathing)Very goodVery goodAgingAverageBestBetterAverageInitial Cost$$$$$$$$$ fluid characteristics impact performance capabilities in transformer application5 fluid differences impact performance6 FluidCharacteristicsMineral OilNatural EsterTransformer performance65 AWR110 C hottest spot85 AWR130 C hottest spotAllows for overload or life extensionReliability- Dielectric strengthDielectric strength declines as heat increases due towater saturationRetains Dielectric strength in presence of waterSelf Drying - Hydrolysis consumes the waterMoisture saturation (@20 C)

4 Keep Moisture out of the Paper!55 ppm1,100 ppmFire safetyFlash point 155 CFire point 160 CFlash point 330 CFire point 360 CEnvironmental footprintNon-biodegradableNon toxic, non-hazardous in soil and waterCarbon neutral Biodegradable in 28 daysHottest Spot Temperature ( )Average Winding Rise (K)(Top Temp Bottom Temp)/2 Transformer solid insulation is limiting factor in transformer life Degrades over time, based upon temperature, loading degree/cycle, and contaminants (water, oxygen, and acids)Design limits defined by insulation system hot spot temperature (HST) Natural Esters (IEEE )

5 Demonstrates 20 C additional thermal capability (compared to mineral oil)Economic value and opportunity Natural Ester filled transformers thermal capability enables lower cost per kVA, longer life, reduced transformer price, and positive NPVI nsulation system is the primary failure mode of a transformer7FR3 fluid Formulation DevelopedASTM Standard PublishedEnvirotemp Dielectric Fluids Business Purchased by Cargill 19 Jun12FR3 fluid Applied to 1stTransformerFR3 fluid Commercially AvailableIEC Standard PublishedIEEES tandard PublishedHigh Temp Insulation System Standards Published199019952000200520102015 DGA Standard PublishedOver 20+ years of experience with Natural EstersCargill begins FR3 fluid production8 Increased Safety - Reduces Fire Risk Improved Environmental Footprint Optimized

6 Transformer Performance Lower total cost Greater ReliabilityNatural Esters:Three important benefits to remember9 Increased Safety - Reduces Fire Risk Natural EstersKey Advantages10 Fire Safety(K class fluid ) -UL and FMNo reported fire related failures!11 Fire SafetyFlash and Fire Point of Ester K-Class Fluids Fluids classified as Fire Resistant (K Class) must have Fire Point above 300 C150200250300350400 Temperature ( C)MineralOilEnvirotemp200 SyntheticSiliconeEnvirotemp FR3 Natural EsterFlash PointFire Point308343360165155270300330 CONFIDENTIAL. This document contains Trade secret information.

7 Disclosure, use or reproduction outside Cargill or inside Cargill, to or by those employees who do not have a need to know is prohibited except as authorized by Cargill in Fire Benefits of K Class High Firepoint No fires/self extinguishing Employees and Stakeholders are safer. Discounted insurance No firewalls needed Reduced construction $$$$ No costly sprinkler systems Smaller footprint Reduced separation distances Better use of land and retail space Increased Safety - Reduces Fire Risk Improved Environmental FootprintNatural EstersKey Advantages14 Natural ester fluid is a better choice for the communities you serve15 Made from a renewable resource->98% vegetable oil-Carbon neutral*-Contains no petroleum, halogens, silicones or sulfurs Non-toxic.

8 Non-hazardous in water and soil- OECD oral and aquatic toxicity test Biodegrades in less than 28 days- Ultimately biodegradable according Environmental Protection Agency (EPA) Recyclable* According to BEES lifecycle analysis Increased Safety - Reduces Fire Risk Improved Environmental Footprint Optimized Transformer Performance Lower total cost Greater ReliabilityNatural Esters Advantages16 Optimize performance: Increase capacity with reduced transformer sizeINCREASE LOADABILITY BY UP TO 20% WITHOUT DEGRADING ASSET LIFE17 IEEE (IEC 60076-14) High temperature insulation system standard Current standard 110oC hot spot with 65 AWR limits transformer capability Envirotemp FR3 fluid -based insulation systems can be run 20oC warmer without degrading life Design new transformers smaller with same or more load capability Existing transformers can be upgraded to provide overload capabilityImprove reliability.

9 Extend insulation and asset life 5-8x longer than mineral oil18 Protecting life of insulation paper is thenumber one factor that determines assetlifeTested, validated and proven19 SPCAA Presentation May 13, 2014 Validated by industryMeets IEEE and IEC standards- More than 250 series of tests conducted on FR3 fluid - IEEE (IEC 60076-14) High temperature insulation system standard enables 75 rise new transformer designsClassified as a less flammable fluid (K-class)- Underwriters Laboratory - FM GlobalEnvironmental testing- Carbon neutral according to BEES lifecycle analysis- Ultimately biodegradable by EPA- Non-toxic and non-hazardous in soil and water by OECDI ndustry recognition- 2013 Presidential Green Chemistry Award- 2013 EPA Design for the Environment (DfE)

10 Designation- USDA BioPrefered Program- EPA Environmental Technology Verification California Environmental Technology Certification- FERC ruling retrofills with FR3 fluid may be capitalized20 Natural EstersMineral OilNew OilASTM D6871 ASTM D3487 IEC 62770 IEC 60296 Use and MaintenanceIEEE 60422 TransformersIEEE 60076 seriesIEC 60076 seriesIEEE IEEE 60076-14 IEC 60076-14 Loading GuideIEC 60076-7 IEC 60076-7 Dissolved GasesIEEE 60599 ASTM, IEEE and IEC natural ester standards FireFM Global Property Loss Prevention Data Sheets, 5-4 TransformersIEC 61936-1 Power installations exceeding 1 kV Part 1.