Free Writing Prospectus

Filed Pursuant to Rule 433

Registration Statement No. 333-203664-02

Northern States Power Company

(a Wisconsin corporation)

$100,000,000 3.75% FIRST MORTGAGE BONDS, SERIES DUE DECEMBER 1, 2047

Issuer:	Northern States Power Company (a Wisconsin corporation)
Issue Format:	SEC Registered
Expected Ratings*:	Aa3/A/A+ (Stable/Stable/Stable) (Moody’s/Standard & Poor’s/Fitch)
Security Type:	First Mortgage Bonds
Pricing Date:	November 27, 2017
Settlement Date:	December 4, 2017 (T+5)
Interest Payment Dates:	Semi-annually on June 1 and December 1, commencing on June 1, 2018
Principal Amount:	$100,000,000
Maturity Date:	December 1, 2047
Reference Benchmark:	2.75% due August 15, 2047
Benchmark Price:	99 - 22
Benchmark Yield:	2.765%
Spread to Reference Benchmark:	+100 bps
Yield to Maturity:	3.765%
Coupon:	3.75%
Price to Public:	99.732% of principal amount
Net Proceeds to Issuer:	$98,857,000 (after underwriting discount but before transaction expenses)
Optional Redemption Provisions:
Make-Whole Call:	Prior to June 1, 2047 (the par call date), T +15 bps (calculated to the par call date)
Par Call:	On or after June 1, 2047, at par
CUSIP/ISIN:	665789 AZ6/US665789AZ63
Minimum Denominations:	$1,000
Joint Book-Running Managers:	Credit Suisse Securities (USA) LLC Morgan Stanley & Co. LLC

*Note: A securities rating is not a recommendation to buy, sell or hold securities and may be subject to revision or withdrawal at any time.

The issuer has filed a registration statement (including a prospectus) with the SEC for the offering to which this communication relates. Before you invest, you should read the prospectus in that registration statement and other documents the issuer has filed with the SEC for more complete information about the issuer and this offering. You may get these documents for free by visiting EDGAR on the SEC website at www.sec.gov. Alternatively, the issuer, any underwriter or any dealer participating in the offering will arrange to send you the prospectus if you request it by calling Credit Suisse Securities (USA) LLC, toll-free at 1-800-221-1037 or Morgan Stanley & Co. LLC, toll-free at 1-866-718-1649.