From: Kenneth Winder [mailto:kwinder@mleainc.com]

Sent: Tuesday, November 01, 2011 9:30 PM

To: Richard Parker

Cc: Corkran, Jerry L; Caitlin Johnson; rick.a nderson@faypwc.com; tballo@earthjustice.org; ScottB@lvmetals.com; john.caskey@ne ma.org; john.cymba lsky@ee.doe.gov; adelaski@standardsasap.org; Teckman@nwcouncil.org; gbf1@pge.com; carlos.gaytan@ge.com; rgreeson@federalpacific.com; bruce.r. hirsch@bge.com; mhyland@appanet.org; dave.millure@metglas.com; Nadel, Steve; wes.patte rson@us.abb.com; Eric.Petersen@aksteel.com; Raymond.Polinski@atimetals.com; rroy@ nrdc.org; robert.saint@nreca.coop; chuck.simmons@pgnmail.com; mark.stoering@xcelener gy.com; cabolduc@lbl.gov; kcoughlin@lbl.gov; Brian Coffey; gjrosenquist@lbl.gov; Rosens tock, Steven; Michael Rivest; Jerry Hodge; jrossetti@mlgw.org; Jim.creevy@nema.org; Me yers, Aaron; Daniel.Cohen@hq.doe.gov; jmauer@standardsasap.org; greg.coulter405@ gmail.com; bsmith@federalpacific.com; pkumar@publicpower.org; Trujillo, Antonio; Phil Hopkinson; ahofmann@publicpower.org; BermanEconomics@gmail.com; Paul.Ryan@hitmet.com ; jerry.schoen@aksteel.com; mwaltner@nrdc.org; chad.kennedy@us.schneider-electric.com; eduardor obles@eaton.com; vijay.tendulkar@onyxpower.com Subject: Re: Transformer Loading Examples

Mr. Parker and Committee: Attached are two spread sheets showing a sampling of tran sformer loading on Cooperative

systems. The first spreadsheet is information from a North Carolina Cooperativ e showing 20 residential transformers, each serving one residential custom er. Annual Peak Load is provided for each of those transformers. As a group, on the annual non- coincidental peak basis, the average peak

transformer load is about 70% of the transformer rated capacity. The second spreadsheet is informati on from a Kentucky Cooperative showing the Annual System Peak load served through distribution tr ansformers. The total kVA capacity of the distribution transformers is only 29% utili zed at the time of the Annual System Peak.

The information attached for these Cooperativ es is not significantly di fferent than other such information that is being provided to the Co mmittee and LBL. I think this information represents normal utility operation for LFMV transformers.

The information attached shows that these C ooperatives do not load th eir transformers heavily

at the time of the distribution tr ansformer peak load, and that th ere is a consider able amount of diversity between the distribu tion transformer peak loads and the System peak load.

Modeling the above type of transformer lo ading will produce results that differ from the original LBL model because the loading in the original model was much different. How much the results change may or may not be significant, but it is important to have confidence that the model represents acceptable operation of these LFMV transformers. An improved model should provide a more correct picture of the operating efficiency, loss costs, and payback period. Hopefully, the sensitiv ity analysis will also be more meaningful.

Ken--



### Kenneth A. Winder, P.E.
Manager-Engineering

Moon Lake Electric Association 800 W Hwy 40

PO Box 278

Roosevelt UT 84066

435.722.5406 Office

435.724.1539 Cell

435.722.5466 Fax

E-Mail: kwinder@mleainc.com

Web Site: www.mleainc.com