From:Mulkey, Dan [mailto:DHM3@pge.com]Sent:Wednesday, December 14, 2011 11:55 AMTo:Phil Hopkinson; Robert BermanCc:Corkran, Jerry L; Aris Marantan; Katie Coughlin; Richard Parker; Brenda Edwards; Brian Coffey; Caitlin Johnson; Dan Cohen; JenniferTiedeman; John Cymbalsky; Chris Bolduc; Freeman, Jeremiah; Emily Marchetti; Zhimei Luo; Puesh Kumar; Alex Hofmann; Andrew Delaski; ArtRosenfeld; Bob Saint; Bob Smith; Carlos Gaytan; Caskey, John; Charlie Drexler; Charlie Stevens; Chris Brown; Clark Silcox; Creevy, Jim; DanielYoung; David Flaten; Eric Peterson; Fernstrom, Gary; Greg Coulter; Greg Rosenquist; Hirsch, Bruce R; James Lass; Jerry Hodge; Jerry Schoen;Jim Raba; Joanna Mauer; John Rossetti; KenWinder; Mahesh P. Sampat; Matthew Nardotti; Maxine Savitz; Meg Waltner; Michael Hyland; MichaelRivest; Millure, Dave; Pamela Costello; PhilHarter; Polinski, Raymond; Rick Anderson;Rob Greeson; Robert van Buskirk; Robin Roy; Ryan, Paul;Scott Beck; Simmons, Chuck; Steve Nadel; Steve Rosenstock; Ted Johnstone; Thomas Petrosino; Tim Ballo; Tom Eckman; Wes PattersonSubject:RE: Distribution Transformer loadingPhil&Robert,Itisincorrecttosaythatwe“target”70%loading.WeusethesmallestkVAsizethat:a)hasacapability(whichisgreaterthannameplate)inexcessoftheexpectedpeakloadb)meets,alongwiththeserviceandanysecondarycables,thevoltageandflickerdroplimitsTheresultisthatontheaverageforthewholeonemillionplustransformers,myaveragepeakloadis70%ofthenameplateAnyindividualtransformercanhavealoadofanywherefrom0.01%to225%ofnameplateatpeak.(Thesmallpole‐bolttransformersdonotcomeanywherenearthe65CriseatnameplateandItakeadvantageofthat.)Ingeneral,distributionequipmentisnotquite“runtofailure”butrather“runtoproblem”.TherehastobeanissuewithatransformerbeforeIwillchangeaninstalledoneout‐customervoltagecomplaint;customeraddingloadinexcessoftransformercapability;polereplacement/relocation;oilleak;etc.Replacementsandnewinstallationsaresizedaccordingtotheloadandthevoltagedrops,butIwouldneverreplaceatransformertogetcloserto70%loading.‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Fortransformerlossesandefficiencies,Iagreeanddisagreewithbothofyou:MostofthesmalltransformerswillseecustomersthatareontheE1rateschedule.Thisisprobably80%ofthetransformersbutislessthan50%ofthe$valueintransformerpurchases.Ourspendonthree‐phasepad‐mountsusuallyexceedsourspendonsingle‐phasepole‐bolts.Theload‐losscomponentofthetransformerlossesisgoingtofollowthesquareofthedailyloadprofilesoneitherthepeak‐dayload‐factornortheyearly‐loadfactoristhecorrectnumbertousefortheefficiencyevaluation.Itshouldbesomewherebetweenthetwo,soDOE’s50%evaluationmaybecorrectforthesmalloverheadtransformers.Letmecallyourattentiontotheotherrateclasses.Ihavesixrateclassesthathaveannualloadfactorsabove75%.Thoserateclassesarealsothelargerloadswhichtendtobesinglecustomersonasinglelargetransformer.Forthelargertransformers,DOE’sevaluationat50%iswaytoolow.DanMulkeySrConsultingElectricalEngineerPacificGas&ElectricCoDHM3@PGE.COM415‐973‐4699office415‐264‐9260cellFrom:Phil Hopkinson [mailto:phopkinson@hvolt.com]Sent:Tuesday, December 13, 2011 7:41 PMTo:Robert BermanCc:Corkran, Jerry L; Mulkey, Dan; Aris Marantan; Katie Coughlin;Richard Parker; Brenda Edwards; Brian Coffey; Caitlin Johnson; Dan Cohen;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; Fernstrom, Gary; 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; PamCostello; Phil Harter; Polinski, Raymond; Rick Anderson; Rob Greeson; Robert van Buskirk; Robin Roy;Ryan, Paul; Scott Beck; Simmons, Chuck; Steve Nadel; Steve Rosenstock; Ted Johnstone; Thomas Petrosino; Tim Ballo; Tom Eckman;WesPattersonSubject:RE: Distribution Transformer loadingHiRobertandall:Youdon’tseemtorelatetometerloadnumbersandseeminsteadtowanttomakethenumbersapplytotransformerloading.IsuggestthatyoucontactDanMulkeyandspeakwithhim.BycopytoDan,youmaywishtomakeacommenthereyourself.Yourarrowsareperfect:1.TheLoadfactorforthemeterE1relatestoanRMSequivalentloadonthetransformerof70%ofnameplateperPG&ELoadingtargets..2.Thepeakdailyloadonthemetermayormaynotbeinsynchwithalloftheothermetersonthattransformerbutthetypicalmeterseespeakdailyloadsof2timestheaverage.Ifallofthemetersareseeingthesamepeakthenthetransformercarriesmorethanratedloadatthattime.3.Idonotseewhythatissounusualtoyoubecauseitisgeneralpracticetohavecoldloadpickupreachashighas200%ofnameplate.TheIEEELoadingguideallowsupto200%ofnameplateloadforupto30minutes.4.Liquidfilleddistributiontransformershaveveryhighthermalridethrough.Thetimeconstantofthecoreandoilistypically30to60minutesandisthereasonfortheexcellentthermalridethrough.Thewindingoveroiltimeconstantisfasterbutthenetresultisatremendouscapabilitytosustainoverloadswithoutsignificantinsulationlossoflife.5.MycontactswithAmerenUEandEmpireDistrictElectricCompanyshowsthatallaretakingadvantageoftheloadingcapabilitiestooffsetsomeofthecostincreasesofnewtransformers.Thisislikelytobecomequitewidespread.Bestregards,PhilPhilip J Hopkinson, PEPresident & CEO HVOLT Inc.3704 High Ridge Rd.Charlotte, NC 28270phopkinson@hvolt.comPh 704-846-3290Fx 704-845-2520Cell 704-236-3320www.hvolt.comFrom:Robert Berman[mailto:bermaneconomics@gmail.com]Sent:Tuesday, December 13, 2011 10:20 PMTo:Phil HopkinsonCc:Robert Berman; Corkran, Jerry L; Dan Mulkey; Aris Marantan; Katie Coughlin; Richard Parker; Brenda Edwards; Brian Coffey; Caitlin Johnson;Dan Cohen; Jennifer Tiedeman; John Cymbalsky; Chris Bolduc; Freeman, Jeremiah; Emily Marchetti; Zhimei Luo; Puesh Kumar; Alex Hofmann;Andrew Delaski; Art Rosenfeld; Bob Saint;Bob Smith; Carlos Gaytan; Caskey, John; Charlie Drexler; Charlie Stevens; Chris Brown; Clark Silcox;Creevy, Jim; Daniel Young; David Flaten; Eric Peterson; Gary Fernstrom; Greg Coulter; Greg Rosenquist; Hirsch, Bruce R; James Lass; JerryHodge; Jerry Schoen; Jim Raba; Joanna Mauer; John Rossetti; KenWinder; Mahesh P. Sampat; Matthew Nardotti; Maxine Savitz; MegWaltner;Michael Hyland; Michael Rivest; Millure, Dave; Pam Costello; PhilHarter; Polinski, Raymond; Rick Anderson; Rob Greeson; Robertvan Buskirk;Robin Roy; Ryan, Paul; Scott Beck; Simmons, Chuck; Steve Nadel;Steve Rosenstock; Ted Johnstone; Thomas Petrosino; Tim Ballo; Tom Eckman;Wes PattersonSubject:Re: Distribution Transformer loadingYou appear to have a knack for ignoring hard data in favorof calculated possibilities, no matter how unlikely or unreasonable.Possible "could" and "can" possibilities are not relevant whenactualexperience is reported. PG&E peak loads are as reported. Seebelow. Moreover, because utilities valuereliability very highly, prudence would obviate against planning to operate daily peaks at133% of nameplate rating. Indeed, any sortof load growth would likelynecessitate frequent replacement in addition to the heightenedoutage risk.Regards,Robert A. Berman, PrincipalBerman Economicswww.BermanEconomics.com1915 Grand CourtVienna, VA 22182703-281-0490703-655-8398 (cell)BermanEconomics@gmail.comOn Dec 13, 2011, at 6:13 PM, Phil Hopkinson wrote:HelloRobertandall:No,hispeakloadsgowellpastthenameplateratingofthetransformers.HeisquiteemphaticthathisRMSequivalentloadonthetransformeris70%ofthenameplaterating.<image002.png>LookcloselyatthesummarychartfortheE1rateclassandIwillguideyouthroughthenumbers:1.Hisaveragemeterdraws0.785kWRMSovera365day,8760houryear.2.Athisdailypeak,theaveragemeterdrawsabout2timestheaverageandhits0.785*0.74/0.39or1.489kWRMS.3.Atmaximumtheloadingonanygivenmetercanhit1.99kWRMS.4.Overalongerperiodlikeamonththeaveragepeakloadpermeteris0.785*0.51/0.39or1.03kWRMS.5.Sinceheachieves70%RMSequivalentloadonaverage,hisdailypeakcouldactuallybe70%*.74/.39or133%ofnameplateifthepeakweretooccuronallmetersonthesametransformeratthesametime.6.Sinceheachieves70%RMSequivalentloadonaverage,wecanseethathisaveragemonthlypeakcanbeashighas70%*0.51/0.39or91%ofnameplateifallofthemetersseethesamepeakconditions.7.Ifthecauseofpeakloadisweatherrelatedthenitisindeedlikelythatthetransformerwillseemorethan100%loadsuchasduringanextremeheatwaveorduringacoldspell.Iwillsoonsendoutloadingpatternsforotherutilities.Thepointisthattherehasbeenachangeinloadingpracticeandwecanexpectmoreofthesameiftransformersellingpricesgetpushedupbyhigherefficiencyrequirementsbeingimposed.Bestregards,PhilPhilip J Hopkinson, PEPresident & CEO HVOLT Inc.3704 High Ridge Rd.Charlotte, NC 28270phopkinson@hvolt.comPh 704-846-3290Fx 704-845-2520Cell 704-236-3320www.hvolt.comFrom:Robert Berman[mailto:bermaneconomics@gmail.com]Sent:Tuesday, December 13, 2011 5:27 PMTo:Phil HopkinsonCc:Robert Berman; Corkran, Jerry L; Dan Mulkey; Aris Marantan; Katie Coughlin; Richard Parker; Brenda Edwards; Brian Coffey; Caitlin Johnson;Dan Cohen; Jennifer Tiedeman; John Cymbalsky; Chris Bolduc; Freeman, Jeremiah; Emily Marchetti; Zhimei Luo; Puesh Kumar; Alex Hofmann;Andrew Delaski; Art Rosenfeld; Bob Saint;Bob Smith; Carlos Gaytan; Caskey, John; Charlie Drexler; Charlie Stevens; Chris Brown; Clark Silcox;Creevy, Jim; Daniel Young; David Flaten; Eric Peterson; Gary Fernstrom; Greg Coulter; Greg Rosenquist; Hirsch, Bruce R; James Lass; JerryHodge; Jerry Schoen; Jim Raba; Joanna Mauer; John Rossetti; KenWinder; Mahesh P. Sampat; Matthew Nardotti; Maxine Savitz; MegWaltner;Michael Hyland; Michael Rivest; Millure, Dave; Pam Costello; PhilHarter; Polinski, Raymond; Rick Anderson; Rob Greeson; Robertvan Buskirk;Robin Roy; Ryan, Paul; Scott Beck; Simmons, Chuck; Steve Nadel;Steve Rosenstock; Ted Johnstone; Thomas Petrosino; Tim Ballo; Tom Eckman;Wes PattersonSubject:Re: Distribution Transformer loadingSorry, the average load factor is what itis -- striving notwithstanding. All the striving in the world is not going to boost the loadfactors of a rural electric, for example, regardless of what they want or how much they want it. That's why Dan reports the annualaverage load at 39% and the peak day loadat 70%. I suspect that his guidance is to make the average load of the transformeron thepeak dayequal to 70% of the nameplate rating. That would make senseas opposed to larger, historicaloversizing factors, and wouldalso lower transformer purchase costs.Dan does, indeed, buy a very large numberof 15 kVa transformers for his E1rateclass (not load class).This is for residentialcustomers in rural mountainous areas. PG&E buys so many in large part because the casualty ratedue to lightening is quite high.Regards,RobertA.Berman,PrincipalBermanEconomicswww.BermanEconomics.com1915GrandCourtVienna,VA22182703‐281‐0490703‐655‐8398(cell)BermanEconomics@gmail.comOn Dec 13, 2011, at 5:07 PM, Phil Hopkinson wrote:GoodafternoonRobertandall:1.Nothatisnotthecorrectinterpretation.IspokeextensivelywithDanMulkey,thePG&ETransformerEngineer.The39%loadfactorisonapermeterbasisandistheaverageloadforthatmeterdividedbythemaximumloadforthatmeter.Sinceallmetersofthesameclassareaverageditistheaverageloaddividedbythemaximumloadforallofthemetersofthatclass.2.Thetransformerloadingisadifferentcalculation.Effectively,PG&EunderDanMulkey’sguidancestrivestomaketheaverageloadonthetransformerequalto70%oftheNameplateratingofthetransformer.3.Transformersarechosenfortheapplicationbasedonachieving70%RMSequivalentloadonthetransformerandonremainingwithinacceptableflickerandloadregulation.Heoftentimeschoosesa15kVAtransformerfor10‐15metersofloadclassE1.IhavespokenwithAmerenUEthisafternoonaswellandtheyhavewithinthelast5yearsmodifiedtheirtransformersizingpolicytogotomuchheavierloadingsoastominimizetheirtransformerpurchasebudget.Bestregards,PhilPhilip J Hopkinson, PEPresident & CEO HVOLT Inc.3704 High Ridge Rd.Charlotte, NC 28270phopkinson@hvolt.comPh 704-846-3290Fx 704-845-2520Cell 704-236-3320www.hvolt.comFrom: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; PamCostello; 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>