6. Borrowings and Other Financing Instruments

Commercial Paper — NSP-Wisconsin meets its short-term liquidity requirements primarily through the issuance of commercial paper and borrowings under its credit facility. Commercial paper outstanding for NSP-Wisconsin was as follows:

(Amounts in Millions, Except Interest Rates)	Three Months Ended March 31, 2013			Twelve Months Ended Dec. 31, 2012
Borrowing limit	$	150		$	150
Amount outstanding at period end		21			39
Average amount outstanding		24			61
Maximum amount outstanding		46			116
Weighted average interest rate, computed on a daily basis		0.34	%		0.39	%
Weighted average interest rate at period end		0.33			0.40

Letters of Credit — NSP-Wisconsin may use letters of credit, generally with terms of one-year, to provide financial guarantees for certain operating obligations. At March 31, 2013 and Dec. 31, 2012, there were no letters of credit outstanding.

Credit Facility — In order to use its commercial paper program to fulfill short-term funding needs, NSP-Wisconsin must have a revolving credit facility in place at least equal to the amount of its commercial paper borrowing limit and cannot issue commercial paper in an aggregate amount exceeding available capacity under this credit facility. The line of credit provides short-term financing in the form of notes payable to banks, letters of credit and back-up support for commercial paper borrowings.

At March 31, 2013, NSP-Wisconsin had the following committed credit facility available (in millions of dollars):

Credit Facility (a)				Drawn (b)				Available
$	150.0			$	21.0			$	129.0

(a)	Credit facility expires in July 2017.

(b)	Includes outstanding commercial paper.

All credit facility bank borrowings, outstanding letters of credit and outstanding commercial paper reduce the available capacity under the credit facility. NSP-Wisconsin had no direct advances on the credit facility outstanding at March 31, 2013 and Dec. 31, 2012.

Other Short-Term Borrowings— The following table presents the notes payable of Clearwater Investments, Inc., a NSP-Wisconsin subsidiary, to Xcel Energy Inc.:

(Amounts in Millions, Except Interest Rates)	March 31, 2013			Dec. 31, 2012
Notes payable to affiliates	$	0.6		$	0.6
Weighted average interest rate		0.33	%		0.33	%