Utility Rate Cases

12 Months Ended

Dec. 31, 2012

Utility Rate Cases [Line Items]

Utility Rate Cases

UTILITY RATE CASES

WPL’s Wisconsin Retail Electric and Gas Rate Case (2013/2014 Test Period) - In May 2012, WPL filed a retail base rate filing based on a forward-looking test period that included 2013 and 2014. The filing requested approval for WPL to implement a decrease in annual base rates for WPL’s retail gas customers of $13 million effective January 1, 2013 followed by a freeze of such gas base rates through the end of 2014. The filing also requested authority to maintain customer base rates for WPL’s retail electric customers at their current levels through the end of 2014. Recovery of the costs for the acquisition of Riverside, the SCR project at Edgewater Unit 5 and the scrubber and baghouse projects at Columbia Units 1 and 2 were included in the request. The recovery of the costs for these capital projects are offset by decreases in rate base resulting from increased net deferred tax liabilities, the impact of changes in the amortizations of regulatory assets and regulatory liabilities, and the reduction of capacity payments. In July 2012, WPL received an order from the PSCW authorizing WPL to implement its retail base rate filing as requested. Refer to Note 1(b) for details of increases to “Regulatory assets” on Alliant Energy’s and WPL’s Consolidated Balance Sheets and regulatory-related credits to “Utility - Other operation and maintenance” in Alliant Energy’s and WPL’s Consolidated Statements of Income in 2012 as a result of the PSCW’s order authorizing WPL to recover previously incurred costs associated with the acquisition of a 25% interest in Edgewater Unit 5 and proposed CACP projects.

WPL’s Wisconsin Retail Electric Rate Case (2011 Test Year) - In April 2010, WPL filed a request with the PSCW to reopen the rate order for its 2010 test year to increase annual retail electric rates for 2011. The request was based on a forward-looking test period that included 2011. The key drivers for the filing included recovery of investments in WPL’s Bent Tree - Phase I wind project and expiring deferral credits, partially offset by lower variable fuel expenses. In December 2010, WPL received an order from the PSCW authorizing an annual retail electric rate increase of $8 million, or approximately 1%, effective January 1, 2011. This $8 million increase in annual rates effective January 1, 2011, combined with the termination of the $9 million interim fuel-related rate increase after December 2010, resulted in a net $1 million decrease in annual retail electric rates charged to customers effective January 2011. Refer to “WPL’s Retail Fuel-related Rate Case (2010 Test Year)” below for additional details of the interim fuel-related rate increase implemented in 2010 and a $5 million reduction to the 2011 test year base rate increase for refunds owed to retail electric customers related to interim fuel cost collections in 2010.

IPL’s Iowa Retail Gas Rate Case (2011 Test Year) - In May 2012, IPL filed a request with the IUB to increase annual rates for its Iowa retail gas customers based on a 2011 historical test year as adjusted for certain known and measurable changes occurring up to 12 months after the commencement of the proceeding. The key drivers for the filing included recovery of capital investments since IPL’s last Iowa retail gas rate case filed in 2005. IPL’s request included a proposal to utilize regulatory liabilities to credit bills of Iowa retail gas customers to help mitigate the impact of the proposed final rate increase on such customers. IPL proposed to reduce customer bills utilizing a gas tax benefit rider over a three-year period by approximately $36 million in aggregate. In conjunction with the filing, IPL implemented an interim retail gas rate increase of $9 million, or approximately 3%, on an annual basis, effective June 4, 2012, without regulatory review and subject to refund pending determination of final rates from the request. In 2012, Alliant Energy and IPL recorded $5 million in gas revenues from IPL’s Iowa retail gas customers related to the interim retail gas rate increase. In August 2012, IPL, the Iowa Office of Consumer Advocate and the Iowa Consumers Coalition filed a unanimous settlement proposal with the IUB addressing all issues among these parties related to this rate case. In November 2012, the IUB approved the settlement agreement between the parties. The parties agreed to, and the IUB approved, an increase in annual rates for IPL’s Iowa retail gas customers of $11 million, or approximately 4%, effective January 10, 2013. The parties and the IUB also agreed to IPL’s proposed gas tax benefit rider.

IPL’s Iowa Retail Electric Rate Case (2009 Test Year) - In March 2010, IPL filed a request with the IUB to increase annual rates for its Iowa retail electric customers based on a 2009 historical test year as adjusted for certain known and measurable changes occurring up to 12 months after the commencement of the proceeding. The key drivers for the filing included recovery of investments in the Whispering Willow - East wind project and emission controls projects at Lansing Unit 4, and recovery of increased electric transmission service costs. In conjunction with the filing, IPL implemented an interim retail electric rate increase of $119 million, on an annual basis, effective March 20, 2010. In February 2011, IPL received an order from the IUB authorizing a final annual retail electric rate increase of $114 million, or approximately 10%. In 2011, IPL refunded $5 million, including interest, to its retail electric customers in Iowa. Refer to Note 1(b) for discussion of the impacts of the IUB’s decision in this rate case on Alliant Energy’s and IPL’s regulatory assets and regulatory liabilities. Refer to Note 1(e) for discussion of the IUB’s decision in this rate case, which disallowed IPL a return on a portion of its Whispering Willow - East wind project costs.

IPL’s Minnesota Retail Electric Rate Case (2009 Test Year) - In May 2010, IPL filed a request with the MPUC to increase annual rates for its Minnesota retail electric customers based on a 2009 historical test year as adjusted for certain known and measurable items at the time of the filing. The key drivers for the filing included recovery of investments in the Whispering Willow - East wind project and emission controls projects at Lansing Unit 4, and recovery of increased electric transmission service costs. In conjunction with the filing, IPL implemented an interim retail rate increase of $14 million, on an annual basis, effective July 6, 2010. In November 2011, IPL received an order from the MPUC authorizing a final annual retail electric rate increase equivalent to $11 million. The final annual retail electric rate increase of $11 million includes $8 million of higher base rates, $2 million from the temporary renewable energy rider and $1 million from the utilization of regulatory liabilities to offset higher electric transmission service costs. Refer to Note 1(b) for discussion of changes to regulatory assets and regulatory liabilities in 2011 based on the MPUC’s decisions in this rate case. Refer to Note 1(e) for discussion of an impairment recognized in 2011 based on the MPUC’s decision regarding the recovery of IPL’s Whispering Willow - East wind project costs.

WPL’s Retail Fuel-related Rate Case (2013 Test Year)- In June 2012, WPL filed a request with the PSCW to decrease annual rates for WPL’s retail electric customers to reflect anticipated decreases in retail fuel-related costs in 2013 compared to the fuel-related cost estimates used to determine rates for 2012. In December 2012, WPL received an order from the PSCW authorizing an annual retail electric rate decrease of $29 million, or approximately 3%, effective January 1, 2013. WPL’s 2013 fuel-related costs will be monitored using an annual bandwidth of plus or minus 2%.

WPL’s Retail Fuel-related Rate Case (2012 Test Year) - In May 2011, WPL filed a request with the PSCW to increase annual retail electric rates to recover anticipated increases in retail fuel-related costs in 2012 due to higher purchased power energy costs and emission compliance costs. In December 2011, WPL received an order from the PSCW authorizing an annual retail electric rate increase of $4 million, effective January 1, 2012, related to expected changes in retail fuel-related costs for 2012. The 2012 fuel-related costs were subject to an annual bandwidth of plus or minus 2%. Retail fuel-related costs incurred by WPL for 2012 were lower than the approved fuel monitoring level by more than the 2% bandwidth resulting in future refunds anticipated to be used to offset fuel-related cost changes in 2014. As of December 31, 2012, Alliant Energy and WPL recorded $11 million in “Regulatory liabilities” on their Consolidated Balance Sheets for refunds anticipated to be used to adjust fuel-related cost changes in 2014.

WPL’s Retail Fuel-related Rate Case (2010 Test Year)-In April 2010, WPL filed a request with the PSCW to increase annual retail electric rates to recover anticipated increased fuel-related costs in 2010. WPL received approval from the PSCW to implement an interim rate increase of $9 million, on an annual basis, effective in June 2010. Updated annual 2010 fuel-related costs during the proceeding resulted in WPL no longer qualifying for a fuel-related rate increase for 2010. In December 2010, the PSCW issued an order authorizing no increase in retail electric rates in 2010 related to fuel-related costs and required the interim rate increase to terminate at the end of 2010. The order also authorized WPL to use $5 million of the interim fuel rates collected in 2010 as a reduction to the 2011 test year base rate increase.

Refer to Note 1(h) for further discussion of WPL’s fuel cost recovery mechanism and Note 1(b) for discussion of various other rate matters.

IPL [Member]

Utility Rate Cases [Line Items]

Utility Rate Cases

UTILITY RATE CASES

WPL’s Wisconsin Retail Electric and Gas Rate Case (2013/2014 Test Period) - In May 2012, WPL filed a retail base rate filing based on a forward-looking test period that included 2013 and 2014. The filing requested approval for WPL to implement a decrease in annual base rates for WPL’s retail gas customers of $13 million effective January 1, 2013 followed by a freeze of such gas base rates through the end of 2014. The filing also requested authority to maintain customer base rates for WPL’s retail electric customers at their current levels through the end of 2014. Recovery of the costs for the acquisition of Riverside, the SCR project at Edgewater Unit 5 and the scrubber and baghouse projects at Columbia Units 1 and 2 were included in the request. The recovery of the costs for these capital projects are offset by decreases in rate base resulting from increased net deferred tax liabilities, the impact of changes in the amortizations of regulatory assets and regulatory liabilities, and the reduction of capacity payments. In July 2012, WPL received an order from the PSCW authorizing WPL to implement its retail base rate filing as requested. Refer to Note 1(b) for details of increases to “Regulatory assets” on Alliant Energy’s and WPL’s Consolidated Balance Sheets and regulatory-related credits to “Utility - Other operation and maintenance” in Alliant Energy’s and WPL’s Consolidated Statements of Income in 2012 as a result of the PSCW’s order authorizing WPL to recover previously incurred costs associated with the acquisition of a 25% interest in Edgewater Unit 5 and proposed CACP projects.

WPL’s Wisconsin Retail Electric Rate Case (2011 Test Year) - In April 2010, WPL filed a request with the PSCW to reopen the rate order for its 2010 test year to increase annual retail electric rates for 2011. The request was based on a forward-looking test period that included 2011. The key drivers for the filing included recovery of investments in WPL’s Bent Tree - Phase I wind project and expiring deferral credits, partially offset by lower variable fuel expenses. In December 2010, WPL received an order from the PSCW authorizing an annual retail electric rate increase of $8 million, or approximately 1%, effective January 1, 2011. This $8 million increase in annual rates effective January 1, 2011, combined with the termination of the $9 million interim fuel-related rate increase after December 2010, resulted in a net $1 million decrease in annual retail electric rates charged to customers effective January 2011. Refer to “WPL’s Retail Fuel-related Rate Case (2010 Test Year)” below for additional details of the interim fuel-related rate increase implemented in 2010 and a $5 million reduction to the 2011 test year base rate increase for refunds owed to retail electric customers related to interim fuel cost collections in 2010.

IPL’s Iowa Retail Gas Rate Case (2011 Test Year) - In May 2012, IPL filed a request with the IUB to increase annual rates for its Iowa retail gas customers based on a 2011 historical test year as adjusted for certain known and measurable changes occurring up to 12 months after the commencement of the proceeding. The key drivers for the filing included recovery of capital investments since IPL’s last Iowa retail gas rate case filed in 2005. IPL’s request included a proposal to utilize regulatory liabilities to credit bills of Iowa retail gas customers to help mitigate the impact of the proposed final rate increase on such customers. IPL proposed to reduce customer bills utilizing a gas tax benefit rider over a three-year period by approximately $36 million in aggregate. In conjunction with the filing, IPL implemented an interim retail gas rate increase of $9 million, or approximately 3%, on an annual basis, effective June 4, 2012, without regulatory review and subject to refund pending determination of final rates from the request. In 2012, Alliant Energy and IPL recorded $5 million in gas revenues from IPL’s Iowa retail gas customers related to the interim retail gas rate increase. In August 2012, IPL, the Iowa Office of Consumer Advocate and the Iowa Consumers Coalition filed a unanimous settlement proposal with the IUB addressing all issues among these parties related to this rate case. In November 2012, the IUB approved the settlement agreement between the parties. The parties agreed to, and the IUB approved, an increase in annual rates for IPL’s Iowa retail gas customers of $11 million, or approximately 4%, effective January 10, 2013. The parties and the IUB also agreed to IPL’s proposed gas tax benefit rider.

IPL’s Iowa Retail Electric Rate Case (2009 Test Year) - In March 2010, IPL filed a request with the IUB to increase annual rates for its Iowa retail electric customers based on a 2009 historical test year as adjusted for certain known and measurable changes occurring up to 12 months after the commencement of the proceeding. The key drivers for the filing included recovery of investments in the Whispering Willow - East wind project and emission controls projects at Lansing Unit 4, and recovery of increased electric transmission service costs. In conjunction with the filing, IPL implemented an interim retail electric rate increase of $119 million, on an annual basis, effective March 20, 2010. In February 2011, IPL received an order from the IUB authorizing a final annual retail electric rate increase of $114 million, or approximately 10%. In 2011, IPL refunded $5 million, including interest, to its retail electric customers in Iowa. Refer to Note 1(b) for discussion of the impacts of the IUB’s decision in this rate case on Alliant Energy’s and IPL’s regulatory assets and regulatory liabilities. Refer to Note 1(e) for discussion of the IUB’s decision in this rate case, which disallowed IPL a return on a portion of its Whispering Willow - East wind project costs.

IPL’s Minnesota Retail Electric Rate Case (2009 Test Year) - In May 2010, IPL filed a request with the MPUC to increase annual rates for its Minnesota retail electric customers based on a 2009 historical test year as adjusted for certain known and measurable items at the time of the filing. The key drivers for the filing included recovery of investments in the Whispering Willow - East wind project and emission controls projects at Lansing Unit 4, and recovery of increased electric transmission service costs. In conjunction with the filing, IPL implemented an interim retail rate increase of $14 million, on an annual basis, effective July 6, 2010. In November 2011, IPL received an order from the MPUC authorizing a final annual retail electric rate increase equivalent to $11 million. The final annual retail electric rate increase of $11 million includes $8 million of higher base rates, $2 million from the temporary renewable energy rider and $1 million from the utilization of regulatory liabilities to offset higher electric transmission service costs. Refer to Note 1(b) for discussion of changes to regulatory assets and regulatory liabilities in 2011 based on the MPUC’s decisions in this rate case. Refer to Note 1(e) for discussion of an impairment recognized in 2011 based on the MPUC’s decision regarding the recovery of IPL’s Whispering Willow - East wind project costs.

WPL’s Retail Fuel-related Rate Case (2013 Test Year)- In June 2012, WPL filed a request with the PSCW to decrease annual rates for WPL’s retail electric customers to reflect anticipated decreases in retail fuel-related costs in 2013 compared to the fuel-related cost estimates used to determine rates for 2012. In December 2012, WPL received an order from the PSCW authorizing an annual retail electric rate decrease of $29 million, or approximately 3%, effective January 1, 2013. WPL’s 2013 fuel-related costs will be monitored using an annual bandwidth of plus or minus 2%.

WPL’s Retail Fuel-related Rate Case (2012 Test Year) - In May 2011, WPL filed a request with the PSCW to increase annual retail electric rates to recover anticipated increases in retail fuel-related costs in 2012 due to higher purchased power energy costs and emission compliance costs. In December 2011, WPL received an order from the PSCW authorizing an annual retail electric rate increase of $4 million, effective January 1, 2012, related to expected changes in retail fuel-related costs for 2012. The 2012 fuel-related costs were subject to an annual bandwidth of plus or minus 2%. Retail fuel-related costs incurred by WPL for 2012 were lower than the approved fuel monitoring level by more than the 2% bandwidth resulting in future refunds anticipated to be used to offset fuel-related cost changes in 2014. As of December 31, 2012, Alliant Energy and WPL recorded $11 million in “Regulatory liabilities” on their Consolidated Balance Sheets for refunds anticipated to be used to adjust fuel-related cost changes in 2014.

WPL’s Retail Fuel-related Rate Case (2010 Test Year)-In April 2010, WPL filed a request with the PSCW to increase annual retail electric rates to recover anticipated increased fuel-related costs in 2010. WPL received approval from the PSCW to implement an interim rate increase of $9 million, on an annual basis, effective in June 2010. Updated annual 2010 fuel-related costs during the proceeding resulted in WPL no longer qualifying for a fuel-related rate increase for 2010. In December 2010, the PSCW issued an order authorizing no increase in retail electric rates in 2010 related to fuel-related costs and required the interim rate increase to terminate at the end of 2010. The order also authorized WPL to use $5 million of the interim fuel rates collected in 2010 as a reduction to the 2011 test year base rate increase.

Refer to Note 1(h) for further discussion of WPL’s fuel cost recovery mechanism and Note 1(b) for discussion of various other rate matters.

WPL [Member]

Utility Rate Cases [Line Items]

Utility Rate Cases

UTILITY RATE CASES

WPL’s Wisconsin Retail Electric and Gas Rate Case (2013/2014 Test Period) - In May 2012, WPL filed a retail base rate filing based on a forward-looking test period that included 2013 and 2014. The filing requested approval for WPL to implement a decrease in annual base rates for WPL’s retail gas customers of $13 million effective January 1, 2013 followed by a freeze of such gas base rates through the end of 2014. The filing also requested authority to maintain customer base rates for WPL’s retail electric customers at their current levels through the end of 2014. Recovery of the costs for the acquisition of Riverside, the SCR project at Edgewater Unit 5 and the scrubber and baghouse projects at Columbia Units 1 and 2 were included in the request. The recovery of the costs for these capital projects are offset by decreases in rate base resulting from increased net deferred tax liabilities, the impact of changes in the amortizations of regulatory assets and regulatory liabilities, and the reduction of capacity payments. In July 2012, WPL received an order from the PSCW authorizing WPL to implement its retail base rate filing as requested. Refer to Note 1(b) for details of increases to “Regulatory assets” on Alliant Energy’s and WPL’s Consolidated Balance Sheets and regulatory-related credits to “Utility - Other operation and maintenance” in Alliant Energy’s and WPL’s Consolidated Statements of Income in 2012 as a result of the PSCW’s order authorizing WPL to recover previously incurred costs associated with the acquisition of a 25% interest in Edgewater Unit 5 and proposed CACP projects.

WPL’s Wisconsin Retail Electric Rate Case (2011 Test Year) - In April 2010, WPL filed a request with the PSCW to reopen the rate order for its 2010 test year to increase annual retail electric rates for 2011. The request was based on a forward-looking test period that included 2011. The key drivers for the filing included recovery of investments in WPL’s Bent Tree - Phase I wind project and expiring deferral credits, partially offset by lower variable fuel expenses. In December 2010, WPL received an order from the PSCW authorizing an annual retail electric rate increase of $8 million, or approximately 1%, effective January 1, 2011. This $8 million increase in annual rates effective January 1, 2011, combined with the termination of the $9 million interim fuel-related rate increase after December 2010, resulted in a net $1 million decrease in annual retail electric rates charged to customers effective January 2011. Refer to “WPL’s Retail Fuel-related Rate Case (2010 Test Year)” below for additional details of the interim fuel-related rate increase implemented in 2010 and a $5 million reduction to the 2011 test year base rate increase for refunds owed to retail electric customers related to interim fuel cost collections in 2010.

IPL’s Iowa Retail Gas Rate Case (2011 Test Year) - In May 2012, IPL filed a request with the IUB to increase annual rates for its Iowa retail gas customers based on a 2011 historical test year as adjusted for certain known and measurable changes occurring up to 12 months after the commencement of the proceeding. The key drivers for the filing included recovery of capital investments since IPL’s last Iowa retail gas rate case filed in 2005. IPL’s request included a proposal to utilize regulatory liabilities to credit bills of Iowa retail gas customers to help mitigate the impact of the proposed final rate increase on such customers. IPL proposed to reduce customer bills utilizing a gas tax benefit rider over a three-year period by approximately $36 million in aggregate. In conjunction with the filing, IPL implemented an interim retail gas rate increase of $9 million, or approximately 3%, on an annual basis, effective June 4, 2012, without regulatory review and subject to refund pending determination of final rates from the request. In 2012, Alliant Energy and IPL recorded $5 million in gas revenues from IPL’s Iowa retail gas customers related to the interim retail gas rate increase. In August 2012, IPL, the Iowa Office of Consumer Advocate and the Iowa Consumers Coalition filed a unanimous settlement proposal with the IUB addressing all issues among these parties related to this rate case. In November 2012, the IUB approved the settlement agreement between the parties. The parties agreed to, and the IUB approved, an increase in annual rates for IPL’s Iowa retail gas customers of $11 million, or approximately 4%, effective January 10, 2013. The parties and the IUB also agreed to IPL’s proposed gas tax benefit rider.

IPL’s Iowa Retail Electric Rate Case (2009 Test Year) - In March 2010, IPL filed a request with the IUB to increase annual rates for its Iowa retail electric customers based on a 2009 historical test year as adjusted for certain known and measurable changes occurring up to 12 months after the commencement of the proceeding. The key drivers for the filing included recovery of investments in the Whispering Willow - East wind project and emission controls projects at Lansing Unit 4, and recovery of increased electric transmission service costs. In conjunction with the filing, IPL implemented an interim retail electric rate increase of $119 million, on an annual basis, effective March 20, 2010. In February 2011, IPL received an order from the IUB authorizing a final annual retail electric rate increase of $114 million, or approximately 10%. In 2011, IPL refunded $5 million, including interest, to its retail electric customers in Iowa. Refer to Note 1(b) for discussion of the impacts of the IUB’s decision in this rate case on Alliant Energy’s and IPL’s regulatory assets and regulatory liabilities. Refer to Note 1(e) for discussion of the IUB’s decision in this rate case, which disallowed IPL a return on a portion of its Whispering Willow - East wind project costs.

IPL’s Minnesota Retail Electric Rate Case (2009 Test Year) - In May 2010, IPL filed a request with the MPUC to increase annual rates for its Minnesota retail electric customers based on a 2009 historical test year as adjusted for certain known and measurable items at the time of the filing. The key drivers for the filing included recovery of investments in the Whispering Willow - East wind project and emission controls projects at Lansing Unit 4, and recovery of increased electric transmission service costs. In conjunction with the filing, IPL implemented an interim retail rate increase of $14 million, on an annual basis, effective July 6, 2010. In November 2011, IPL received an order from the MPUC authorizing a final annual retail electric rate increase equivalent to $11 million. The final annual retail electric rate increase of $11 million includes $8 million of higher base rates, $2 million from the temporary renewable energy rider and $1 million from the utilization of regulatory liabilities to offset higher electric transmission service costs. Refer to Note 1(b) for discussion of changes to regulatory assets and regulatory liabilities in 2011 based on the MPUC’s decisions in this rate case. Refer to Note 1(e) for discussion of an impairment recognized in 2011 based on the MPUC’s decision regarding the recovery of IPL’s Whispering Willow - East wind project costs.

WPL’s Retail Fuel-related Rate Case (2013 Test Year)- In June 2012, WPL filed a request with the PSCW to decrease annual rates for WPL’s retail electric customers to reflect anticipated decreases in retail fuel-related costs in 2013 compared to the fuel-related cost estimates used to determine rates for 2012. In December 2012, WPL received an order from the PSCW authorizing an annual retail electric rate decrease of $29 million, or approximately 3%, effective January 1, 2013. WPL’s 2013 fuel-related costs will be monitored using an annual bandwidth of plus or minus 2%.

WPL’s Retail Fuel-related Rate Case (2012 Test Year) - In May 2011, WPL filed a request with the PSCW to increase annual retail electric rates to recover anticipated increases in retail fuel-related costs in 2012 due to higher purchased power energy costs and emission compliance costs. In December 2011, WPL received an order from the PSCW authorizing an annual retail electric rate increase of $4 million, effective January 1, 2012, related to expected changes in retail fuel-related costs for 2012. The 2012 fuel-related costs were subject to an annual bandwidth of plus or minus 2%. Retail fuel-related costs incurred by WPL for 2012 were lower than the approved fuel monitoring level by more than the 2% bandwidth resulting in future refunds anticipated to be used to offset fuel-related cost changes in 2014. As of December 31, 2012, Alliant Energy and WPL recorded $11 million in “Regulatory liabilities” on their Consolidated Balance Sheets for refunds anticipated to be used to adjust fuel-related cost changes in 2014.

WPL’s Retail Fuel-related Rate Case (2010 Test Year)-In April 2010, WPL filed a request with the PSCW to increase annual retail electric rates to recover anticipated increased fuel-related costs in 2010. WPL received approval from the PSCW to implement an interim rate increase of $9 million, on an annual basis, effective in June 2010. Updated annual 2010 fuel-related costs during the proceeding resulted in WPL no longer qualifying for a fuel-related rate increase for 2010. In December 2010, the PSCW issued an order authorizing no increase in retail electric rates in 2010 related to fuel-related costs and required the interim rate increase to terminate at the end of 2010. The order also authorized WPL to use $5 million of the interim fuel rates collected in 2010 as a reduction to the 2011 test year base rate increase.

Refer to Note 1(h) for further discussion of WPL’s fuel cost recovery mechanism and Note 1(b) for discussion of various other rate matters.