From:Robert Berman [mailto:bermaneconomics@gmail.com]Sent:Tuesday, December 13, 2011 4:17 PMTo:Corkran, Jerry LCc:Dan Mulkey; Phil Hopkinson; Aris Marantan; Katie Coughlin; Richard Parker; Brenda Edwards; Brian Coffey; Caitlin Johnson; DanCohen;Jennifer Tiedeman; John Cymbalsky; Chris Bolduc; Freeman, Jeremiah; Emily Marchetti; Zhimei Luo; Puesh Kumar; Alex Hofmann; AndrewDelaski; Art Rosenfeld; Bob Saint; Bob Smith; Carlos Gaytan; Caskey, John; Charlie Drexler; Charlie Stevens; Chris Brown; ClarkSilcox; Creevy,Jim; Daniel Young; David Flaten; Eric Peterson; Gary Fernstrom;Greg Coulter; Greg Rosenquist; Hirsch, Bruce R; James Lass; Jerry Hodge; JerrySchoen; Jim Raba; Joanna Mauer; John Rossetti; Ken Winder; MaheshP. Sampat; Matthew Nardotti; Maxine Savitz; Meg Waltner; MichaelHyland; Michael Rivest; Millure, Dave; Pamela Costello; Phil Harter; Polinski, Raymond; Rick Anderson; Rob Greeson; Robert Berman; Robert vanBuskirk; Robin Roy; Ryan, Paul; Scott Beck; Simmons, Chuck; SteveNadel; Steve Rosenstock; Ted Johnstone; Thomas Petrosino; TimBallo; TomEckman; Wes PattersonSubject:Re: Distribution Transformer loadingIt appears that the 70% load factor occursonly on the peak day. The annual load factorfor 80% of the meters is reported as 39%. Thisis consistent with 38% implied load factor PG&E filed init's 2007 rate case (A=$7.268, B=$1.063). These results are not inconsistentwith the national distribution of loads used by LBNL.Regards,RobertA.Berman,PrincipalBermanEconomicswww.BermanEconomics.com1915GrandCourtVienna,VA22182703‐281‐0490703‐655‐8398(cell)BermanEconomics@gmail.comOn Dec 13, 2011, at 3:26 PM, Corkran, Jerry L wrote:DanMulkeyandPhilHopkinson–theattachedloadingdataandtheexplanationofhowPG&Eloadstheirnewtransformersatatargeted70%ofthenameplateratingisveryfactualandthemostaccurateexplanationIhaveheardabouthowtheutilitiesloadtheirnewtransformers.Wehaveallheardtheterms“SmartGrid”.Thisappearstobeanexampleofasmartcustomerusingthelatesttechnologytoleadthewayonefficientuseofnewtransformers.Forthe30yeartimeframethatisbeingconsideredfortheDOEtransformerefficiencyrules,itseemslogicalthatmostutilitieswilladoptasimilarsmartprocessasisbeingusedbyPG&Etosizethetransformersandthataloadingtargetsimilartothe70%loadingtargetusedbyPG&Ewillbeadoptedbytheutilityindustry.Thisisexpectedtoresultinloadlevelsmuchhigherthanthe25%to40%loadsusedbytheDOEtocalculatethepaybacksforthevariouslosslevelsconsidered.Thekeyquestioniswhatloadingwillbeusedonnewtransformerstobeinstalledandnotwhatloadingexistsonsomeunitinstalledlongbeforethesmartmetersexisted.Dan–AreyouavailabletoansweremailsiftheDOEWGhasadditionalquestions?MembersoftheDOEWGwhoareutilityemployees:PleasecommentaboutthepracticethatPGEisusingtoloadtheirnewtransformers.Whatdoesyourcompanycurrentlydotosizetransformersandwhatwillyourcompanydointhefuturetoefficientlyloadthenewtransformersinstalledonyoursystems?MembersoftheDOEandNavigantwhoareinvolvedintheevaluationsofthetransformerdesigns:Pleasecomment‐WouldtheDOEandNavigantconsiderusingahigherloadfactorintheDOEpaybackcalculations?Basedonthe70%loadfactortargetedbyPG&Efor6millioncustomers,itseemsthattheDOEstudypaybackresultsarenotaccurateandthattheyshouldberevisedtosomeloadfactorthatreflectsthelatesttechnologythattheutilitieswillroutinelybeusingbasedonthefuture30yeartimeframebeingconsidered.Regards,JerryCorkranFrom:Mulkey, Dan [mailto:DHM3@pge.com]Sent:Tuesday, December 13, 2011 1:42 PMTo:Phil HopkinsonCc:Corkran, Jerry L; Meyers, Aaron; Trujillo, AntonioSubject:RE: Distribution Transformer loadingPhil:ItisgoodtohearfromyouagainasImissedattendingthelastIEEETransformersCommitteeMeetingsinBoston.YouhaveaskedaboutloadcyclesatPacificGas&Electricandinfactwehavepublicinformationthatisreadilyavailableonourwebsite.Thereareapproximately5.1millionmetersonthePG&Esystem.Theaveragedatafromtestmetersforeachrateclassfromresidentialtocommercialandindustrialisdisplayedonanhourlybasisforall8760hoursinayear.Multipleyearsofdataareavailableonthepublicwebsite.TheattachedEXCELspreadsheetisanextractofthedatafor2006.Therateclassesaredefinedinthesecondattachment.Thisdataisnotorganizedbytransformertypebutthereareanumberoffactorsthataresignificanttounderstandingthedisplays:1.Thesummarydatabyrateclassisshownattheverybottomofthespreadsheet.2.Asnapshotofthesummarydataisshownbelow:3.<image001.png>4.ThehourlyreadingsarethekWHrsconsumedwhichisalsotheaveragekWloadduringthathour.5.RateclassE1isthemostabundantclass.Iestimatethatitaccountsforapproximately80%ofthemeters.6.RateclassE7isalsoresidentialbutisTimeofUseservice,andprobablyaccountsfor~5%ofthemeters.Thisclassismostoftenadvantageousforhomeswherepeoplecanshifttheirenergyconsumptiontooff‐peaktimes.7.Thevariousotherrateclassesarealsodefinedinattachment2.8.Theyearlyloadfactorisequaltotheaverageloaddividedbythemaxload.9.ForPG&Etheaveragetransformerisloadedtoapproximately70%ofnameplate.Whilethepeakloadsarenormallywithinthecapabilityofthetransformer,thepeakloadswilloftenexceedthenameplateratingofthetransformer.10.Itisusuallythephysicallocationandgroupingofthecustomerservicepointsthatdeterminestheneededtransformer.11.FormosttransformerinstallationsthelimitingfactorisusuallythevoltageorflickerdropratherthanthekVAsizeofthetransformer.12.Agiventransformercanbeplacedintoserviceforawidevarietyofloads.Forinstance,thesame25kVAsingle‐phasepad‐mountcouldbeusedtosupplyeverythingfromasinglesignallight,toasingleisolatedresidentialcustomer,tofifteenorsoresidentialcustomersinasubdivisioninacoastalarea.13.Whiletheaveragedistributiontransformerserves5customers,therangeisfromonetoseveralhundred.14.PG&Eattemptstotakeadvantageofthefullcapabilityofourtransformerstoachievefavorableeconomicsforourratepayers.Ihopethatthisexplanationhelps.Bestregards,DanMulkeySrConsultingElectricalEngineerDHM3@PGE.COM415‐973‐4699office415‐264‐9260cell<ElectricRateSchedules.xls><2006LoadProfile.xls>