UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 14A

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NRG ENERGY, INC.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

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Your Vote Counts! *Please check the meeting materials for any special requirements for meeting attendance. Smartphone users Point your camera here and vote without entering a control number For complete information and to vote, visit www.ProxyVote.com Control # V33837-P04715 NRG ENERGY, INC. C/O OFFICE OF GENERAL COUNSEL 804 CARNEGIE CENTER PRINCETON, NJ 08540-6213 NRG ENERGY, INC. 2024 Annual Meeting Vote by April 24, 2024 11:59 PM ET You invested in NRG ENERGY, INC. and it’s time to vote! You have the right to vote on proposals being presented at the Annual Meeting. This is an important notice regarding the availability of proxy material for the stockholder meeting to be held on April 25, 2024. Get informed before you vote View the Notice and Proxy Statement and Annual Report online OR you can receive a free paper or email copy of the material(s) by requesting prior to April 11, 2024. If you would like to request a copy of the material(s) for this and/or future stockholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to sendmaterial@proxyvote.com. If sending an email, please include your control number (indicated below) in the subject line. Unless requested, you will not otherwise receive a paper or email copy. Vote Virtually at the Meeting* April 25, 2024 9:00 AM ET Virtually at: www.virtualshareholdermeeting.com/NRG2024

Vote at www.ProxyVote.com Prefer to receive an email instead? While voting on www.ProxyVote.com, be sure to click “Delivery Settings”. Voting Items Board Recommends V33838-P04715 THIS IS NOT A VOTABLE BALLOT This is an overview of the proposals being presented at the upcoming stockholder meeting. Please follow the instructions on the reverse side to vote these important matters. 1. To elect thirteen directors. Nominees: 1a. E. Spencer Abraham For 1b. Antonio Carrillo For 1c. Matthew Carter, Jr. For 1d. Lawrence S. Coben For 1e. Heather Cox For 1f. Elisabeth B. Donohue For 1g. Marwan Fawaz For 1h. Kevin T. Howell For 1i. Paul W. Hobby For 1j. Alex Pourbaix For 1k. Alexandra Pruner For 1l. Anne C. Schaumburg For 1m. Marcie C. Zlotnik For 2. To approve, on a non-binding advisory basis, NRG Energy, Inc.’s executive compensation. For 3. To ratify the appointment of KPMG LLP as NRG Energy, Inc.’s independent registered public accounting firm for the 2024 fiscal year. For NOTE: Such other business as may properly come before the meeting or any adjournment thereof.