Exhibit 24-APOWER OF ATTORNEY      I, KEVIN G. MOUG, do hereby constitute and appoint JOHN D. ERICKSON and GEORGE A. KOECK, orany one of them, my Attorney-in-Fact for the purpose of signing, in my name and on my behalf asChief Financial Officer and Treasurer of Otter Tail Corporation, the Annual Report of Otter TailCorporation on Form 10-K for its fiscal year ended December 31, 2007, and any and all amendments tosaid Annual Report, and to deliver on my behalf said Annual Report and any and all amendmentsthereto, as each thereof is so signed, for filing with the Securities and Exchange Commissionpursuant to the Securities Exchange Act of 1934, as amended.Date: February 6, 2008       /s/  Kevin G. Moug Kevin G. Moug     In Presence of:     /s/ Lauris N. Molbert       /s/ John Erickson     
 

 
POWER OF ATTORNEY      I, John MacFarlane, do hereby constitute and appoint JOHN D. ERICKSON and GEORGE A. KOECK, orany one of them, my Attorney-in-Fact for the purpose of signing, in my name and on my behalf asDirector of Otter Tail Corporation, the Annual Report of Otter Tail Corporation on Form 10-K forits fiscal year ended December 31, 2007, and any and all amendments to said Annual Report, and todeliver on my behalf said Annual Report and any and all amendments thereto, as each thereof is sosigned, for filing with the Securities and Exchange Commission pursuant to the Securities ExchangeAct of 1934, as amended.Date: February 6, 2008       /s/ John MacFarlane  John MacFarlane     In Presence of:     /s/ Edward McIntyre       /s/ Arvid Liebe   
 

 
POWER OF ATTORNEY      I, Karen Bohn, do hereby constitute and appoint JOHN D. ERICKSON and GEORGE A. KOECK, or anyone of them, my Attorney-in-Fact for the purpose of signing, in my name and on my behalf asDirector of Otter Tail Corporation, the Annual Report of Otter Tail Corporation on Form 10-K forits fiscal year ended December 31, 2007, and any and all amendments to said Annual Report, and todeliver on my behalf said Annual Report and any and all amendments thereto, as each thereof is sosigned, for filing with the Securities and Exchange Commission pursuant to the Securities ExchangeAct of 1934, as amended.Date: February 6, 2008       /s/ Karen Bohn  Karen Bohn     In Presence of:     /s/ Nathan Partain        /s/ Lori Talafous      
 

 
POWER OF ATTORNEY      I, Dennis Emmen, do hereby constitute and appoint JOHN D. ERICKSON and GEORGE A. KOECK, or anyone of them, my Attorney-in-Fact for the purpose of signing, in my name and on my behalf asDirector of Otter Tail Corporation, the Annual Report of Otter Tail Corporation on Form 10-K forits fiscal year ended December 31, 2007, and any and all amendments to said Annual Report, and todeliver on my behalf said Annual Report and any and all amendments thereto, as each thereof is sosigned, for filing with the Securities and Exchange Commission pursuant to the Securities ExchangeAct of 1934, as amended.Date: February 6, 2008       /s/ Dennis Emmen  Dennis Emmen     In Presence of:     /s/ Joyce Nelson Schuette              /s/ Lori Talafous        
 

 
POWER OF ATTORNEY      I, Arvid Liebe, do hereby constitute and appoint JOHN D. ERICKSON and GEORGE A. KOECK, or anyone of them, my Attorney-in-Fact for the purpose of signing, in my name and on my behalf asDirector of Otter Tail Corporation, the Annual Report of Otter Tail Corporation on Form 10-K forits fiscal year ended December 31, 2007, and any and all amendments to said Annual Report, and todeliver on my behalf said Annual Report and any and all amendments thereto, as each thereof is sosigned, for filing with the Securities and Exchange Commission pursuant to the Securities ExchangeAct of 1934, as amended.Date: February 6, 2008       /s/ Arvid Liebe              Arvid Liebe     In Presence of:     /s/ Gary Spies         /s/ James Stake    
 

 
POWER OF ATTORNEY      I, Edward J. McIntyre, do hereby constitute and appoint JOHN D. ERICKSON and GEORGE A. KOECK,or any one of them, my Attorney-in-Fact for the purpose of signing, in my name and on my behalf asDirector of Otter Tail Corporation, the Annual Report of Otter Tail Corporation on Form 10-K forits fiscal year ended December 31, 2007, and any and all amendments to said Annual Report, and todeliver on my behalf said Annual Report and any and all amendments thereto, as each thereof is sosigned, for filing with the Securities and Exchange Commission pursuant to the Securities ExchangeAct of 1934, as amended.Date: February 6, 2008       /s/ Edward J. McIntyre      Edward J. McIntyre                                 In Presence of:     /s/ John MacFarlane                                          /s/ James B. Stake                                           
 

 
POWER OF ATTORNEY      I, Joyce Nelson Schuette, do hereby constitute and appoint JOHN D. ERICKSON and GEORGE A.KOECK, or any one of them, my Attorney-in-Fact for the purpose of signing, in my name and on mybehalf as Director of Otter Tail Corporation, the Annual Report of Otter Tail Corporation on Form10-K for its fiscal year ended December 31, 2007, and any and all amendments to said Annual Report,and to deliver on my behalf said Annual Report and any and all amendments thereto, as each thereofis so signed, for filing with the Securities and Exchange Commission pursuant to the SecuritiesExchange Act of 1934, as amended.Date: February 6, 2008       /s/ Joyce Nelson Schuette      Joyce Nelson Schuette                               In Presence of:     /s/ Dennis Emmen                                          /s/ Kevin Moug                                            
 

 
POWER OF ATTORNEY      I, Nathan Partain, do hereby constitute and appoint JOHN D. ERICKSON and GEORGE A. KOECK, orany one of them, my Attorney-in-Fact for the purpose of signing, in my name and on my behalf asDirector of Otter Tail Corporation, the Annual Report of Otter Tail Corporation on Form 10-K forits fiscal year ended December 31, 2007, and any and all amendments to said Annual Report, and todeliver on my behalf said Annual Report and any and all amendments thereto, as each thereof is sosigned, for filing with the Securities and Exchange Commission pursuant to the Securities ExchangeAct of 1934, as amended.Date: February 6, 2008       /s/ Nathan Partain           Nathan Partain                                             In Presence of:     /s/ Karen Bohn                                          /s/ Lori Talafous                                       
 

 
POWER OF ATTORNEY      I, Gary Spies, do hereby constitute and appoint JOHN D. ERICKSON and GEORGE A. KOECK, or anyone of them, my Attorney-in-Fact for the purpose of signing, in my name and on my behalf asDirector of Otter Tail Corporation, the Annual Report of Otter Tail Corporation on Form 10-K forits fiscal year ended December 31, 2007, and any and all amendments to said Annual Report, and todeliver on my behalf said Annual Report and any and all amendments thereto, as each thereof is sosigned, for filing with the Securities and Exchange Commission pursuant to the Securities ExchangeAct of 1934, as amended.Date: February 6, 2008       /s/ Gary Spies               Gary Spies                                               In Presence of:     /s/ Arvid Liebe                                          /s/ James B. Stake