Confirmation of Forward Stock Sale Transaction

Exhibit 10.2

EXECUTION COPY

September 24, 2013

Confirmation of Forward Stock Sale Transaction

Dear Sir/Madam:

The purpose of this letter agreement (this “Confirmation”) is to confirm the terms and conditions of the Transaction entered into between Wells Fargo Bank, National Association (“Party A”) and Westar Energy, Inc. (“Party B”) on the Trade Date specified below (the “Transaction”). This confirmation constitutes a “Confirmation” as referred to in the ISDA Master Agreement specified below.

The definitions and provisions contained in the 2002 ISDA Equity Derivatives Definitions (as published by the International Swaps and Derivatives Association, Inc. (“ISDA”)) (the “Equity Definitions”) are incorporated into this Confirmation. In the event of any inconsistency between the Equity Definitions and this Confirmation, this Confirmation will govern. Any reference to a currency shall have the meaning contained in Annex A to the 1998 ISDA FX and Currency Option Definitions, as published by ISDA.

GENERAL TERMS:

2

3

4

5

Conditions to Effectiveness:

The effectiveness of this Confirmation on the Effective Date shall be subject to (i) the condition that the representations and warranties of Party B contained in Section 3(a) of the Agreement and the Underwriting Agreement dated the date hereof among Party B and J.P. Morgan Securities LLC, Wells Fargo Securities, LLC, Citigroup Global Markets Inc. and UBS Securities LLC, as representatives of the underwriters, and the other underwriters named therein (the “Underwriting Agreement”), and any certificate delivered pursuant to the Underwriting Agreement by Party B be true and correct on the Effective Date as if made as of the Effective Date, (ii) the condition that the representations and warranties of Party A contained in Section 3(a) of the Agreement be true and correct on the Effective Date as if made as of the Effective Date, (iii) the condition that Party B have performed all of the obligations required to be performed by it under the Underwriting Agreement on or prior to the Effective Date, (iv) the satisfaction of all of the conditions set forth in Section 5 of the Standard Provisions to the Underwriting Agreement and (v) the condition that the Underwriting Agreement has not been terminated pursuant to Section 10 thereof. In addition, if Party A (or its affiliate), in Party A’s commercially reasonable judgment, is unable to borrow and deliver for sale a number of Shares equal to the Base Shares on the Effective Date or if, in Party A’s commercially reasonable judgment, borrowing such number of Shares would entail a stock loan cost of more than 60 basis points per annum with respect to all or any portion of such Shares, the effectiveness of this Confirmation shall be limited to the number of Shares Party A (or its affiliate) may borrow on the Effective Date at a cost of not more than 60 basis points per annum.

Additional Representations and Warranties of Party B: Party B hereby represents and warrants to Party A (each of such representations to be deemed part of Section 3(a) of the Agreement) as of the date hereof and on the Effective Date, and, in the case of clause (b), on such dates and on the Settlement Date, that:

6

Covenants of Party B: Party B hereby agrees that, so long as either party has or may have any obligation under the Transaction, that:

7

Covenants and Representation of Party A:

Extraordinary Dividends:

If a record date for an Extraordinary Dividend occurs on or after the Effective Date, but prior to the Maturity Date (such date subject to deferral by up to 45 Scheduled Trading Days in connection with any deferral of a Settlement Date beyond the originally scheduled Maturity Date pursuant to the provisions opposite the caption “Settlement Date” above), Party B shall pay an amount, as determined by the Calculation Agent, in cash equal to the product of (a) such Extraordinary Dividend, and (b) the number of Base Shares on such record date (in the case of any such record date that occurs during an Unwind Period, subject to reduction by the Calculation Agent by a number of Shares equal to the number of Settlement Shares relating to such Unwind Period for

8

which Party A has unwound its hedge), to Party A on the earlier of (i) the date on which such Extraordinary Dividend is paid by the Issuer to holders of record of the Shares and (ii) the Maturity Date (such date subject to deferral by up to 45 Scheduled Trading Days in connection with any deferral of a Settlement Date beyond the originally scheduled Maturity Date pursuant to the provisions opposite the caption “Settlement Date” above). “Extraordinary Dividend” means the per Share amount of any cash dividend or distribution declared by the Issuer with respect to the Shares that is specified by the board of directors of the Issuer as an “extraordinary” dividend.

Acceleration Events: An Acceleration Event shall occur if:

9

Termination Settlement:

If a Settlement Date is specified following an Acceleration Event (a “Termination Settlement Date”), Physical Settlement shall apply with respect to such Termination Settlement Date as set forth above, subject to the provisions described under “Limit on Beneficial Ownership” below. If, upon designation of a Termination Settlement Date by Party A, Party B fails to deliver the Settlement Shares relating to such Termination Settlement Date when due or otherwise fails to perform its obligations in connection therewith, it shall be an Event of Default with respect to Party B and Section 6 of the Agreement shall apply. If an Acceleration Event occurs during an Unwind Period relating to a number of Settlement Shares to which Cash Settlement or Net Share Settlement applies, then on the Termination Settlement Date relating to such Acceleration Event, notwithstanding any election to the contrary by Party B, Cash Settlement or Net Share Settlement shall apply to the portion of the Settlement Shares relating to such Unwind Period as to which Party A has unwound its hedge and Physical Settlement shall apply in respect of (x) the remainder (if any) of such Settlement Shares and (y) the Settlement Shares designated by Party A in respect of such Termination Settlement Date.

Certain Changes In Law:

Upon the occurrence of any Change In Law specified in clause (Y) of the definition thereof, Party A and Party B agree to negotiate in good faith for at least 20 calendar days to amend this Confirmation to take account of the resulting “materially increased cost” as such phrase is used in clause (Y) of the definition of “Change In Law.” Such amendment may, if agreed by Party A and Party B, result in a Change In Law specified in clause (Y) of the definition thereof being treated as if it were a Change In Law specified in clause (X) of the definition thereof, as described in clause (e) under the heading “Acceleration Events” above. If, after negotiating in good faith for at least 20 calendar days to so amend this Confirmation, Party A and Party B do not agree on such an amendment, the relevant Change In Law specified in clause (Y) of the definition thereof shall be treated as if it were a Change In Law specified in clause (X) of the definition thereof, as described in clause (e) under the heading “Acceleration Events” above.

Rule 10b5-1:

It is the intent of Party A and Party B that the purchase of Shares by Party A during any Unwind Period comply with the requirements of Rule 10b5-1(c)(1)(i)(B) of the Exchange Act and that this Confirmation shall be interpreted to comply with the requirements of Rule 10b5-1(c).

Party B acknowledges that, except as otherwise provided herein, (i) during any Unwind Period Party B does not have, and shall not attempt to exercise, any influence over how, when or whether to effect purchases of Shares by Party A (or its agent or affiliate) in connection with this Confirmation and (ii) Party B is entering into the Agreement and this Confirmation in good faith and not as part of a plan or scheme to evade compliance with federal securities laws including, without limitation, Rule 10b-5 promulgated under the Exchange Act.

Party B hereby agrees with Party A that during any Unwind Period Party B shall not communicate, directly or indirectly, any Material Non-Public Information (as defined herein) to any Equity Personnel (as defined below). For purposes of the Transaction, “Material Non-Public Information” means information relating to Party B or the Shares that (a) has not been widely disseminated by wire service, in one or more newspapers of general

10

circulation, by communication from Party B to its shareholders or in a press release, or contained in a public filing made by Party B with the Securities and Exchange Commission and (b) a reasonable investor might consider to be of importance in making an investment decision to buy, sell or hold Shares. For the avoidance of doubt and solely by way of illustration, information should be presumed “material” if it relates to such matters as dividend increases or decreases, earnings estimates, changes in previously released earnings estimates, significant expansion or curtailment of operations, a significant increase or decline of orders, significant merger or acquisition proposals or agreements, significant new products or discoveries, extraordinary borrowing, major litigation, liquidity problems, extraordinary management developments, purchase or sale of substantial assets, or other similar information. For purposes of the Transaction, “Equity Personnel” means any employee on the trading side of the Equity Derivatives Group of Wells Fargo Bank, National Association and does not include Mr. Michael Collins, Ms. Mary Lou Guttmann, Ms. Jenny Dahlen, Mr. Andrew Ralston and Mr. Michael D. Golden (or any other person or persons reasonably designated from time to time by the Compliance Group of Party A, subject to written notice of such designation being delivered by Party A to Party B).

Interpretive Letter:

The parties intend for this Confirmation to constitute a “Contract” as described in the letter dated October 6, 2003 submitted by Robert W. Reeder and Leslie N. Silverman to Paula Dubberly of the staff of the Securities and Exchange Commission (the “Staff”) to which the Staff responded in an interpretive letter dated October 9, 2003.

Restricted Shares:

If Party B is unable to comply with clause (h) of “Covenants of Party B” above in this Section 3 because of a change in law or a change in interpretation or the policy of the Securities and Exchange Commission or its staff, or Party A otherwise determines in its reasonable, good faith opinion based on the advice of outside counsel that any Shares to be delivered to Party A by Party B may not be freely returned by Party A to securities lenders as described in clause (h) of “Covenants of Party B” above in this Section 3, then the Calculation Agent may, in consultation with Party B, make adjustments to the terms of the Transaction to preserve the economic intent of the parties, including adjustments to the Forward Price to reflect any lack of liquidity in restricted Shares, and the parties shall work together in good faith to effect settlement of the Transaction in a commercially reasonable manner and in compliance with applicable law and regulations.

Maximum Share Delivery:

Notwithstanding any other provision of this Confirmation, in no event will Party B be required to deliver in settlement of this Transaction on any Settlement Date, whether pursuant to Physical Settlement, Net Share Settlement or Termination Settlement, more than the number of Base Shares to Party A.

Assignment:

Party A may assign or transfer any of its rights or delegate any of its duties hereunder to any affiliate of Party A without the prior written consent of Party B, so long as the senior unsecured debt rating (the “Credit Rating”) of such affiliate (or any guarantor of its obligations under the Transaction) is equal to or greater than the Credit Rating of the ultimate parent of Party A, as specified by Standard and Poor’s Rating Services or Moody’s Investor Service, Inc., at the time of such assignment or transfer. In connection with any assignment or transfer pursuant to the immediately preceding sentence, (i) the guarantee of any guarantor of the relevant transferee’s obligation shall constitute a Credit Support Document under the Agreement and (ii) the assignee or transferee shall deliver to Party B a properly executed IRS Form W-9 or Form W-8 (together with all necessary attachments) establishing an exemption from backup withholding under the Code. Notwithstanding any other provision of this Confirmation to the contrary requiring or allowing Party A to purchase or receive any Shares from Party B, Party A may designate any of its affiliates to purchase or receive such Shares or otherwise to perform Party A’s obligations in respect of the Transaction and any such designee may assume such obligations, and Party A shall be discharged of its obligations to Party B only to the extent of any such performance. Any affiliate of Party A designated as described in the immediately preceding sentence shall deliver to Party B a properly executed IRS Form W-9 or Form W-8 (together with all necessary attachments) establishing an exemption from backup withholding under the Code.

11

Matters Relating to Agent:

Each party agrees and acknowledges that:

(a) Wells Fargo Securities, LLC, as agent, (the “Agent”) acts solely as agent for Party A on a disclosed basis with respect to the transactions contemplated hereunder.

(b) The Agent is registered as a broker-dealer with the U.S. Securities and Exchange Commission and the Financial Industry Regulatory Authority (FINRA), is acting hereunder for and on behalf of Party A solely in its capacity as agent for Party A pursuant to instructions from Party A, and is not and will not be acting as Party B’s agent, broker, advisor or fiduciary in any respect under or in connection with this Transaction.

(c) In addition to acting as Party A’s agent in executing the Transaction, the Agent is authorized from time to time to give written payment and/or delivery instructions to Party B directing it to make its payments and/or deliveries under the Transaction to an account of the Agent for remittance to Party A (or its designee), and for that purpose any such payment or delivery by Party B to the Agent shall be treated as a payment or delivery to Party A.

(d) Except as otherwise provided herein, any and all notices, demands, or communications of any kind transmitted in writing by either Party A or Party B under or in connection with the Transaction will be transmitted exclusively by such party to the other party through the Agent at the following address:

Wells Fargo Securities, LLC

375 Park Avenue

New York, NY 10152

Attention: Documentation Group

Telephone No.: (212) 214-6100

Facsimile No.: (212) 214-5913

(e) The Agent shall have no responsibility or liability to Party A or Party B for or arising from (1) any failure by either Party A or Party B to perform any of their respective obligations under or in connection with the Transaction, (2) the collection or enforcement of any such obligations, or (3) the exercise of any of the rights and remedies of either Party A or Party B under or in connection with the Transaction. Each of Party A and Party B agrees to proceed solely against the other to collect or enforce any such obligations, and the Agent shall have no liability in respect of the Transaction except for its gross negligence or willful misconduct in performing its duties as the agent of Party A.

(f) Upon written request, the Agent will furnish to Party A and Party B the date and time of the execution of the Transaction and a statement as to the source and amount of any remuneration received or to be received by the Agent in connection with the Transaction.

Indemnity:

Party B agrees to indemnify Party A and its affiliates and their respective directors, officers, agents and controlling parties (Party A and each such affiliate or person being an “Indemnified Party”) from and against any and all losses, claims, damages and liabilities, joint and several, incurred by or asserted against such Indemnified Party arising out of, in connection with, or relating to, any breach of any covenant or representation made by Party B in this Confirmation or the Agreement. In addition, Party B will reimburse any Indemnified Party for all reasonable expenses (including reasonable legal fees and reasonable expenses) in connection with the investigation of, preparation for, or defense of any pending or threatened claim or any action or proceeding arising therefrom (whether or not such Indemnified Party is a party thereto) at the time, and only to the extent

12

that the relevant loss, claim, damage, liability or expense is found in a final and nonappealable judgment by a court of competent jurisdiction to have resulted from a breach of a covenant or representation made by Party B in this Confirmation or the Agreement. For the avoidance of doubt, Party B will not be liable under this Indemnity paragraph to the extent that any loss, claim, damage, liability or expense is found in a final and nonappealable judgment by a court of competent jurisdiction to have resulted from Party A’s gross negligence, fraud, bad faith and/or willful misconduct or a breach of any representation or covenant of Party A contained in this Confirmation or the Agreement.

Miscellaneous:

Agreement Regarding Set-off and Collateral:

Notwithstanding Section 6(f) or any other provision of the Agreement or any other agreement between the parties to the contrary, the obligations of Party B hereunder are not secured by any collateral. Obligations under the Transaction shall not be set off against any other obligations of the parties, whether arising under the Agreement, this Confirmation, under any other agreement between the parties hereto, by operation of law or otherwise, and no other obligations of the parties shall be set off against obligations under the Transaction, whether arising under the Agreement, this Confirmation, under any other agreement between the parties hereto, by operation of law or otherwise, and each party hereby waives any such right of setoff. In calculating any amounts under Section 6(e) of the Agreement, notwithstanding anything to the contrary in the Agreement, (a) separate amounts shall be calculated as set forth in such Section 6(e) with respect to (i) the Transaction and (ii) all other Transactions, and (b) such separate amounts shall be payable pursuant to Section 6(d)(ii) of the Agreement.

Delivery of Cash:

For the avoidance of doubt, nothing in this Confirmation shall be interpreted as requiring Party B to deliver cash in respect of the settlement of the Transaction, except (i) as set forth under “Extraordinary Dividends” above or (ii) in circumstances where the cash settlement thereof is within Party B’s control (including, without limitation, where Party B so elects to deliver cash or fails timely to deliver Shares in respect of such settlement). For the avoidance of doubt, the preceding sentence shall not be construed as limiting any damages that may be payable by Party B as a result of a breach of or an indemnity under this Confirmation or the Agreement.

Status of Claims in Bankruptcy:

Party A acknowledges and agrees that this confirmation is not intended to convey to Party A rights with respect to the transactions contemplated hereby that are senior to the claims of common stockholders in any U.S. bankruptcy proceedings of Party B; provided, however, that nothing herein shall limit or shall be deemed to limit Party A’s right to pursue remedies in the event of a breach by Party B of its obligations and agreements with respect to this Confirmation and the Agreement; and provided further that nothing herein shall limit or shall be deemed to limit Party A’s rights in respect of any transaction other than the Transaction.

Limit on Beneficial Ownership:

Notwithstanding any other provisions hereof, Party A shall not have the “right to acquire” (within the meaning of NYSE Rule 312.04(g)) Shares hereunder and Party A shall not be entitled to take delivery of any Shares deliverable hereunder (in each case, whether in connection with the purchase of Shares on any Settlement Date

13

or any Termination Settlement Date) to the extent (but only to the extent) that, after such receipt of any Shares hereunder, (i) the Share Amount would exceed the Applicable Share Limit, or (ii) Party A and each person subject to aggregation of Shares with Party A under Section 13 or Section 16 of the Exchange Act and rules promulgated thereunder (the “Party A Group”) would directly or indirectly beneficially own (as such term is defined for purposes of Section 13 or Section 16 of the Exchange Act and rules promulgated thereunder) in excess of the lesser of (A) 7.5% of the then outstanding Shares or (B) 6,226,133 Shares (the “Threshold Number of Shares”). Any purported delivery hereunder shall be void and have no effect to the extent (but only to the extent) that, after such delivery, (i) the Share Amount would exceed the Applicable Share Limit or (ii) the Party A Group would directly or indirectly so beneficially own in excess of the Threshold Number of Shares. If any delivery owed to Party A hereunder is not made, in whole or in part, as a result of this provision, Party B’s obligation to make such delivery shall not be extinguished, and Party B shall make such delivery as promptly as practicable after, but in no event later than one Exchange Business Day after, Party A gives notice to Party B that, after such delivery, (i) the Share Amount would not exceed the Applicable Share Limit and (ii) the Party A Group would not directly or indirectly so beneficially own in excess of the Threshold Number of Shares.

The “Share Amount” as of any day is the number of Shares that Party A and any person whose ownership position would be aggregated with that of Party A (Party A or any such person, a “Party A Person”) under any law, rule, regulation, regulatory order or organizational documents or contracts of Party B that are, in each case, applicable to ownership of Shares (“Applicable Restrictions”), own, beneficially own, constructively own, control, hold the power to vote or otherwise meet a relevant definition of ownership of under any Applicable Restriction, as determined by Party A in its reasonable discretion. The “Applicable Share Limit” means a number of Shares equal to (A) the minimum number of Shares that could give rise to reporting or registration obligations or other requirements (including obtaining prior approval from any person or entity) of a Party A Person, or could result in an adverse effect on a Party A Person, under any Applicable Restriction, as determined by Party A in its reasonable discretion, minus (B) 1% of the number of Shares outstanding.

Other Forward:

Party A acknowledges that Party B has entered into a substantially identical forward transaction for the Shares on the date hereof (the “Other Forward”) with an affiliate of J.P. Morgan Securities LLC. Party A and Party B agree that if Party B designates a Settlement Date with respect to the Other Forward and for which Cash Settlement or Net Share Settlement is applicable, and the resulting Unwind Period for the Other Forward coincides for any period of time with an Unwind Period for the Transaction (the “Overlap Unwind Period”), Party B shall notify Party A prior to the commencement of such Overlap Unwind Period of the first Exchange Business Day and length of such Overlap Unwind Period, and Party A shall only be permitted to purchase Shares to unwind its hedge in respect of the Transaction on every other Exchange Business Day that is not a Suspension Day during such Overlap Unwind Period, commencing on the second day of such Overlap Unwind Period.

Severability:

If any term, provision, covenant or condition of this Confirmation, or the application thereof to any party or circumstance, shall be held to be invalid or unenforceable in whole or in part for any reason, the remaining terms, provisions, covenants, and conditions hereof shall continue in full force and effect as if this Confirmation had been executed with the invalid or unenforceable provision eliminated, so long as this Confirmation as so modified continues to express, without material change, the original intentions of the parties as to the subject matter of this Confirmation and the deletion of such portion of this Confirmation will not substantially impair the respective benefits or expectations of parties to this Agreement; provided, however, that this severability provision shall not be applicable if any provision of Section 2, 5, 6 or 13 of the Agreement (or any definition or provision in Section 14 to the extent that it relates to, or is used in or in connection with any such Section) shall be so held to be invalid or unenforceable.

Miscellaneous:

14

Withholding Tax Imposed on Payments to Non-US Counterparties Under the United States Foreign Account Tax Compliance Act:

“Indemnifiable Tax” as defined in Section 14 of the Agreement shall not include any U.S. federal withholding tax imposed or collected pursuant to Sections 1471 through 1474 of the Code, any current or future regulations or official interpretations thereof, any agreement entered into pursuant to Section 1471(b) of the Code, or any fiscal or regulatory legislation, rules or practices adopted pursuant to any intergovernmental agreement entered into in connection with the implementation of such Sections of the Code (a “FATCA Withholding Tax”). For the avoidance of doubt, a FATCA Withholding Tax is a Tax the deduction or withholding of which is required by applicable law for the purposes of Section 2(d) of the Agreement.

15

Please confirm that the foregoing correctly sets forth the terms of our agreement by signing and returning this Confirmation.

Confirmed as of the date first written above: