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RE: Clarification onplant capacity factor

- revised Units 1&2 BARTupdate. Parker, James M to: AaronWorstell 10/20/2011 01:36 PM Cc: VanessaHinkle Hide Details From: "Parker,James M" <jmparker@pplweb.com> To: Aaron Worstell/R8/uSEPAlUS@EPA Cc:VanessaHinkle/R8/USEPAlUS@EPA

Aaron. The capacity factor we used was calculated by the plant performance engineers. The value (92%) is a maximum achieved during the years 2001-2004. The normal way the performance folks calculate Capacity Factor is based upon the net annual load and net annual rating. The way it is done is by taking the produced MWhr(net)divided by period hours and then dividing by the net unit rating in MW (net) or: Net Production for the Period (MWHr) + period hours + Net Plant Rating (MW)

# = Plant Capacity Factorforthe period I hope this answers your question. Let me know ifyou have any other questions. Thanks Jim 406-237-6932 -----Original Message----­ From: Worstell.Aaron@epamail.epa.gov [mai1to:Worstell.Aaron@eRamail.eRa.gov] Sent: Wednesday, October 19,2011 2:17 PM To: Parker, James M

file://C:\Documents and Settings\vhinkle\Local Settings\Temp\notes7**A42A6\~web0476.htm** 2/1/2012Page 2 of5 Subject: RE: Clarification on plant capacity factor
- revised Units 1&2 BART update. Thanks Jim In particular, I am interested in whether the capacity factor was calculated as the gross annual load divided by the gross annual capability, both in MWh. Aaron J. Worstell Environmental Engineer U.S. Environmental Protection Agency
- Region 8 Air Program
- Mail Code 8P-AR 1595 Wynkoop Street Denver, CO 80202 Phone: 303-312-6073 Fax: 303-312-6064

From: "Parker, James M" <jmparker@pplweb.com> To: Aaron Worstell/R8/USEPAlUS@EPA Cc: Vanessa Hinkle/R8/USEPAlUS@EPA Date: 

### 10/19/2011 01 :57 PM Subject: RE: Clarification on plant capacity factor
- revised Units 1&2 BART update.

Aaron. In looking back on the data, Ifound I may have told you the wrong years that we based our CF on. I have an inquiry to the person who actually put this information together and gave it to our consultant in 2007. He recently retired but is available for questions. I'll let you know what Ifind out - on your most recent question and on the timeframe. Thanks. Jim -----Original Message----­ From: WorsteII.Aaron@epamail.epa.gov [ mailto:Worstell.Aaron@epamail.epa.govl Sent: Tuesday, October 18, 2011 2:28 PM To: Parker, James M Cc: Hinkle.Vanessa@epamail.epa.gov Subject: RE: Clarification on plant capacity factor
- revised Units 1&2 BART update.

file://C:\Documents and Settings\vhinkle\Local Settings\Temp\notes7**A42A6\~web0476.htm** 2/1/2012Page 3 of5
Jim- Thanks for your quick response. Can you describe how the capacity factor for each ofthe five years was calculated? For example, is it based on the annual gross load (MWh) as reported to CAMD? Aaron J. Worstell Environmental Engineer U.S. Environmental Protection Agency
- Region 8Air Program
- Mail Code 8P-AR 1595 Wynkoop Street Denver, CO 80202 Phone: 303-312-6073 Fax: 303-312-6064

From: "Parker, James M" <jmparker@pplweb.com> To: Aaron Worstell/R8/USEPAlUS@EPA Cc: Vanessa Hinkle/R8/USEPAlUS@EPA Date: 

### 10/18/2011 01:15 PM Subject: RE: Clarification on plant capacity factor
- revised Units 1&2 BART update.

Aaron
- The capacity factor was developed in 2007, the date ofour original BART submittal. The CF was derived by taking the average capacity factor ofthe five years 2003-2007, with the 2007 CF values used in the average being a projection to year's end (since the year wasn't complete at the time ofthe analysis). Also, pursuant to our correspondence last week, attached please find revisions for our Units 1&2 September 23, 2011 submittal. I've attached the revised pages and also a complete revised report. Please let me know ifyou have any questions. Thanks. Jim 406-237-6932

-----Original Message----­ file:1Ie:\Documents and Settings\vhinkle\Local Settings\Temp\notes7A4**2A6\~we** b0476.htm 2/1/2012

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.... Page 4 of5 From: WorsteII.Aaron@epamail.epa.gov [**mailto:Worstell.A~ron@epamail.eR-'L9QV]** Sent: Tuesday, October 18, 2011 8:12 AM To: Parker, James M Subject: Clarification on plant capacity factor
Hi JimIn your NOx update for Colstrip 1 and 2 (September 2011), you use a plant capacity of92%. Can you tell me howthis was derived? Thanks in advance. Aaron J. Worstell Environmental Engineer U.S. Environmental Protection Agency
- Region 8 Air Program
- Mail Code 8P-AR 1595 Wynkoop Street Denver, CO 80202 Phone: 303-312-6073 Fax: 303-312-6064 The information contained in this message is intended only for the personal and confidential use ofthe recipient(s) named above. Ifthe reader ofthis message is not the intended recipient or an agent responsible for delivering it to the intended recipient, you are hereby notified that you have received this document in error and that any review, dissemination, distribution, or copying ofthis message is strictly prohibited. Ifyou have received this communication in error, please notify us immediately, and delete the original message. [attachment "NOX Control Update to PPL Montana's Colstrip Generatiing Station
­ Revised pages(Oct2011).pdf' deleted by Aaron WorsteIl/R8/USEPAlUS] [attachment "NOx Control Update to PPL Montana's Colstrip Generating Station BART Report (Revised).pdf' deleted by Aaron WorsteIl/R8/USEPAlUS] The information contained in this message is intended only for the personal and confidential use ofthe recipient(s) named above. Ifthe reader ofthis message is not the intended recipient or an agent responsible for delivering it to the intended recipient, you are hereby notified that you have received this document in error and that any review, dissemination, distribution, or copying ofthis message is strictly prohibited. Ifyou have received this communication in error, please notify us immediately, and delete the original message.

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