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RE: Clarification on plant capacity factor - revised Units 1&2 BART update. 

Parker, James M 

to: 

Aaron Worstell 

10/20/2011 01:36 PM 

Cc: 

Vanessa Hinkle 

Hide Details 

From: "Parker, James M" <jmparker@pplweb.com> 

To: Aaron Worstell/R8/uSEPAlUS@EPA 

Cc: Vanessa Hinkle/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 Factor for the period 

I hope this answers your question. Let me know if you 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\notes7A42A6\~web0476.htm 2/1/2012 
Page 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, I found 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 I find 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\notes7A42A6\~web0476.htm 2/1/2012 
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Jim- Thanks for your quick response. Can you describe how the capacity factor for 

each of the 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 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: 10/18/2011 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 of our original BART 

submittal. The CF was derived by taking the average capacity factor of the 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 of the 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 if you have any questions. 

Thanks. 

Jim 

406-237-6932 

-----Original Message----­

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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 

of 92%. Can you tell me how this 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 

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