X0304 4 2012-02-29 0001326160 Duke Energy CORP DUK 0001319653 Trent Keith 550 S. TRYON STREET CHARLOTTE NC 28202 1 GrpExec&Pres-Commer Businesses Common Stock 2012-02-29 4 S 0 33031 20.947 D 25792 D Common Stock 1144 I By Spouse The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $20.900 to 21.001, inclusive. The reporting person undertakes to provide to Duke Energy Corporation, any security holder of Duke Energy Corporation, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote (1) to this Form 4. /s/ David S. Maltz, Attorney-in-fact for B. Keith Trent 2012-03-02