as amended December 13, 2023

Exhibit 10.21

DOMINION ENERGY, INC.

2023 PERFORMANCE GRANT PLAN

1. Purpose. The purpose of the 2023 Performance Grant Plan (the “Plan”) is to set forth the terms of 2023 Performance Grants (“Performance Grants”) awarded by Dominion Energy, Inc., a Virginia corporation (the “Company”). This Plan contains the performance goals for the awards, the performance criteria, the target and maximum amounts payable, and other applicable terms and conditions. Capitalized terms not otherwise defined herein shall have the meanings given them in the Company’s 2014 Incentive Compensation Plan, as amended.

2. Definitions.

a. Beneficiary. Means the individual, individuals, entity, entities or the estate of a Participant entitled to receive the amounts payable under a Performance Grant, if any, upon the Participant’s death.

b. Cause. For purposes of this Plan, the term “Cause” will have the meaning assigned to that term under a Participant’s Employment Continuity Agreement with the Company, as such Agreement may be amended from time to time.

c. Committee. Means the Compensation & Talent Development Committee of the board of directors of the Company (or any successor board committee designated by the board of directors of the Company to administer this Plan).

d. Company Pension Plan. Means the applicable pension plan of the Company or its subsidiaries, if any, in which the Participant is eligible to participate as of the Date of Grant, which may include either the Dominion Energy Pension Plan or the SCANA Corporation Retirement Plan or any successor thereto, but excluding the cash balance portion of any such plan.

e. Date of Grant. February 1, 2023.

f. Disability or Disabled. Means a “disability” as defined under Treasury Regulation Section 1.409A-3(i)(4). The Committee will determine whether or not a Disability exists and its determination will be conclusive and binding on the Participant.

g. Participant. An officer of the Company or a Dominion Company who receives a Performance Grant on the Date of Grant.

h. Performance Period. The 36-month period beginning on January 1, 2023 and ending on December 31, 2025.

i. Retire or Retirement. For purposes of this Plan, the term Retire or Retirement means a voluntary termination of employment on a date when the Participant is eligible for early or normal retirement benefits under the terms of the Company Pension Plan, or would be eligible if any crediting of deemed additional years of age or service applicable to the Participant under a supplemental retirement plan of the Company was applied under the Company Pension Plan, as in effect at the time of the determination, or, for a Participant who is not eligible to participate in a Company Pension Plan, a voluntary termination of employment on or after age 55, unless (in each case) the Company’s Chief Executive Officer in their sole discretion (or, if the Participant is the Company’s Chief Executive Officer, the Committee in its sole discretion) determines that the Participant’s retirement is detrimental to the Company.

j. Target Amount. The dollar amount designated in the written notice to the Participant communicating the Performance Grant.

3. Performance Grants. A Participant will receive a written notice of the amount designated as the Participant’s Target Amount for the Performance Grant payable under the terms of this Plan. The actual payout may be from 0% to 200% of the Target Amount, depending on the achievement of the performance goals.

4. Performance Achievement and Time of Payment. Upon the completion of the Performance Period, the Committee will determine the final performance goal achievement of each of the performance criteria described in Section 6 and Exhibit A. The Company will then calculate the final amount of each Participant’s Performance Grant based on such performance goal achievement. Except as provided in Sections 7(b) or 8, the Committee will determine the time of payout of the Performance Grants, provided that in no event will payment be made later than March 15, 2026. Performance Grants shall be paid in cash.

5. Forfeiture. Except as provided in Sections 7 and 8, a Participant's right to payout of a Performance Grant will be forfeited if the Participant’s employment with the Company or a Dominion Company terminates for any reason before the end of the Performance Period.

6. Performance Goals. Payout of Performance Grants will be based on the performance goal achievement of the performance criteria described in this Section 6 and the performance goal achievement of the performance criteria to be determined by the Committee and set forth in Exhibit A.

a. Relative TSR Performance. Relative Total Shareholder Return Performance (“Relative TSR Performance”) will determine fifty percent (50%) of the Target Amount (“TSR Percentage”). Relative TSR Performance is defined in Section 6(b) below. The percentage of the TSR Percentage that will be paid out, if any, is based on the following table:

To the extent that the Company’s Relative TSR Performance ranks in a percentile between the 25th and 85th percentile in the table above, then the TSR Percentage payout will be interpolated between the corresponding TSR Percentage payout set forth above. In addition to the foregoing payments, and regardless of the Company’s Relative TSR Performance, the following may be earned: (i) an additional payment of 25% of the TSR Percentage will be made if the Company’s Price-Earnings Ratio (as defined in Section 6(c) below) is at or above the 50th percentile and below the top third of the group of companies (inclusive of the Company) used to measure Relative TSR Performance in accordance with Section 6(b), or (ii) an additional payment of 50% of the TSR Percentage will be made if the Company’s Price-Earnings Ratio is at or above the top third of the group of companies (inclusive of the Company) used to measure Relative TSR Performance in accordance with Section 6(b) (the “Performance Adder”). The Committee may reduce or eliminate payment of the Performance Adder in its sole discretion.

The overall percentage payment under the entire Performance Grant may not exceed 200% of the Target Amount.

b. Determination of Relative TSR Performance. Relative TSR Performance will be measured based on where the Company’s total shareholder return during the Performance Period ranks in relation to the total shareholder returns of the companies that are members of the Company’s compensation peer group as of the Date of Grant as set forth below (the “Comparison Companies”):

The Comparison Companies shall be adjusted during the Performance Period as follows:

(i) In the event of a merger, acquisition or business combination transaction of a Comparison Company with or by another Comparison Company, effective upon the public announcement of the transaction, the surviving entity shall remain a Comparison Company and the non-surviving entity shall cease to be a Comparison Company (provided that, if the proposed transaction is subsequently terminated before the Relative TSR Performance is calculated, then the non-surviving company shall be retroactively reinstated as a Comparison Company);

(ii) If it is publicly announced that a Comparison Company will be acquired by another company that is not a Comparison Company, or in the event a “going private transaction” is publicly announced where the Comparison Company will not be the surviving entity or will otherwise no longer be publicly traded, the company shall cease to be a Comparison Company as of the date such announcement is made (provided that, if the proposed transaction is subsequently terminated before the Relative TSR Performance is calculated, then the company shall be retroactively reinstated as a Comparison Company);

(iii) In the event of a spinoff, divestiture, or sale of a substantial portion of assets of a Comparison Company, the Comparison Company shall no longer be a Comparison Company if the company’s reported revenue (in its GAAP accounts) for the four most recently reported quarters ending on or before the last day of the Performance Period falls below 40% of Dominion Energy’s reported revenue (in its GAAP accounts) for the four most recently reported quarters on or before the last day of the Performance Period; and

(iv) In the event of a bankruptcy of a Comparison Company, such company shall remain a Comparison Company and its stock price will continue to be tracked for purposes of Relative TSR Performance. If the company liquidates, it will remain a Comparison Company and its stock price will be reduced to zero for the remaining Performance Period.

Total shareholder return consists of the difference between the value of a share of common stock at the beginning (the volume-weighted average price (VWAP) of the first 20 trading days of the Performance Period) and end (the VWAP of the last 20 trading days of the Performance Period), plus the value of gross dividends paid as if reinvested in stock and other appropriate adjustments for such events as stock splits. For purposes of Relative TSR Performance, the total shareholder return of the Company and the Comparison Companies will be calculated using data from Bloomberg or another comparable source. As soon as practicable after the completion of the Performance Period, the total shareholder returns of the Comparison Companies will be calculated and ranked from highest to lowest by the Committee. The Company’s total shareholder return will then be ranked in terms of which percentile it would have placed in among the Comparison Companies.

c. Price-Earnings Ratio. “Price-Earnings Ratio” for the Company and each of the Comparison Companies means the forward price-earnings ratio (i.e. the share price on the last day of the Performance Period divided by the expected earnings per share for the year following the end of the Performance Period) reported as of the last day of the Performance Period as sourced from FactSet or such other financial data provider as the Committee may determine. The expected earnings per share will be the mean of relevant analyst recommendations. Price-Earnings Ratio performance will be measured based on where the Company’s Price-Earnings Ratio ranks in relation to the Price-Earnings Ratios of the Comparison Companies. As soon as practicable after the completion of the Performance Period, the Price-Earnings Ratios of the Comparison Companies will be determined and ranked from highest to lowest by the Committee. The Company’s Price-Earnings Ratio will then be ranked in terms of which percentile it placed in among the Comparison Companies.

7. Retirement, Involuntary Termination without Cause, Death or Disability.

a. Retirement or Involuntary Termination without Cause. Except as provided in Section 8, if a Participant Retires during the Performance Period or if a Participant’s employment is involuntarily

terminated by the Company or a Dominion Company without Cause during the Performance Period, and in either case the Participant would have been eligible for a payment if the Participant had remained employed until the end of the Performance Period, the Participant will receive a pro-rated payout of the Participant’s Performance Grant equal to the payment the Participant would have received had the Participant remained employed until the end of the Performance Period multiplied by a fraction, the numerator of which is the number of whole months from the first day of the calendar month coinciding with or immediately preceding the Date of Grant to the first day of the month coinciding with or immediately following the date of the Participant’s retirement or termination of employment, and the denominator of which is the number of whole months from the first day of the calendar month coinciding with or immediately preceding the Date of Grant to the last day of the Performance Period. Payment will be made after the end of the Performance Period at the time provided in Section 4 based on the performance goal achievement approved by the Committee. If the Participant Retires, however, no payment will be made if the Company’s Chief Executive Officer in their sole discretion (or, if the Participant is the Company’s Chief Executive Officer, the Committee in its sole discretion) determines that the Participant’s Retirement is detrimental to the Company.

b. Death or Disability. If, while employed by the Company or a Dominion Company, a Participant dies or becomes Disabled during the Performance Period, the Participant or, in the event of the Participant’s death, the Participant’s Beneficiary will receive a lump sum cash payment equal to the product of (i) and (ii) where:

(i) is the amount that would be paid based on the predicted performance used for determining the compensation cost recognized by the Company for the Participant’s Performance Grant for the latest financial statement filed with the Company’s Annual Report on Form 10-K or Quarterly Report on Form 10-Q immediately prior to the event; and

(ii) is a fraction, the numerator of which is the number of whole months from the first day of the calendar month coinciding with or immediately preceding the Date of Grant to the first day of the calendar month coinciding with or immediately following the date of the Participant’s death or Disability, and the denominator of which is the number of whole months from the first day of the calendar month coinciding with or immediately preceding the Date of Grant to the last day of the Performance Period.

Payment under this Section 7(b) will be made as soon as administratively feasible (and in any event within sixty (60) days) after the date of the Participant’s death or Disability, and the Participant shall not have the right to any further payment under this Agreement. In the event of the Participant’s death, payment will be made to the Participant’s designated Beneficiary.

8. Qualifying Change of Control. Upon a Qualifying Change of Control prior to the end of the Performance Period, provided the Participant has remained continuously employed with the Company or a Dominion Company from the Date of Grant to the date of the Qualifying Change of Control, the Participant will receive a lump sum cash payment equal to the greater of (i) the Target Amount or (ii) the total payout that would be made at the end of the Performance Period if the predicted performance used for determining the compensation cost recognized by the Company for the Participant’s Performance Grant for the latest financial statement filed with the Company’s Annual Report on Form 10-K or Quarterly Report on Form 10-Q immediately prior to the Qualifying Change of Control was the actual performance for the Performance Period (in either case, the “COC Payout Amount”). Payment will be made on or as soon as administratively feasible following the Qualifying Change of Control date and in no event later than sixty (60) days following the Qualifying Change of Control date. If a Qualifying Change of Control occurs prior to the end of the Performance Period and after a Participant has Retired or been involuntarily terminated without Cause pursuant to Section 7(a) above, then the Participant will receive a pro-rated payout of the Participant’s Performance Grant, equal to the COC Payout Amount multiplied by the fraction set forth in Section 7(a) above, with payment occurring in a cash lump sum on or as soon as administratively feasible (but in any event within sixty (60) days) after the Qualifying Change of Control date. Following any payment under this Section 8, the Participant shall not have the right to any further payment under this Agreement.

9. Termination for Cause. Notwithstanding any provision of this Plan to the contrary, if the Participant’s employment with the Company or a Dominion Company is terminated for Cause (as defined by the

Employment Continuity Agreement between the Participant and the Company), the Participant will forfeit all rights to their Performance Grant.

10. Clawback of Award Payment.

11. Miscellaneous.

d. Performance Goal Adjustments. The Committee may at any time, in its sole discretion, make any adjustments to the performance goals set forth in this award or in Exhibit A, or to the calculation of the Company’s financial or other results for the Performance Period or any portion thereof, or may reduce or increase any applicable Percentage Payouts, in order to reflect any unusual or infrequent events, such as or related to new legislation, regulatory orders/outcomes, asset write-offs, weather, storms, supply chain disruptions, commodity prices, or mergers, acquisitions or dispositions involving the Company, that were not contemplated at the time of grant.

e. Governing Law. This Plan shall be governed by the laws of the Commonwealth of Virginia, without regard to its choice of law provisions.

f. Binding Effect. This Plan will be binding upon and inure to the benefit of the legatees, distributes, and personal representatives of Participants and any successors of the Company.

g. Section 409A. This Plan and the Performance Grants hereunder are intended to comply with Section 409A of the Internal Revenue Code of 1986, as amended (“Code Section 409A”), and shall be interpreted to the maximum extent possible in accordance with such intent. To the extent necessary to comply with Code Section 409A, no payment will be made earlier than six months after a Participant’s termination of employment other than for death if the Performance Grant is subject to Code Section 409A and the Participant is a “specified employee” (within the meaning of Code Section 409A(a)(2)(B)(i)).

h. Administration. The Plan shall be administered by the Committee, which shall have all of the applicable powers and authority set forth in Section 19 of the Company’s 2014 Incentive Compensation Plan with respect to this Plan and the Performance Grants awarded hereunder, the terms of which are incorporated by reference herein.

j. Notice. All notices and other communications required or permitted to be given under this Plan shall be in writing and shall be deemed to have been duly given if delivered personally or mailed first class, postage prepaid, as follows: (a) if to the Company—at the principal business address of the Company to the attention of the Corporate Secretary of the Company; and (b) if to any Participant—at the last address of the Participant known to the sender at the time the notice or other communication is sent.

k. Interpretation. Unless otherwise specifically provided under the terms of any such plan or program, settlements of awards received by participants under the Plan shall not be deemed a part of a participant’s regular, recurring compensation for purposes of calculating payments or benefits from any benefit plan or severance program of the Company or a Dominion Company or any severance pay law of any country. Nothing contained in the Plan will be deemed in any way to limit or restrict the Company or any Dominion Company from making any award or payment to any person under any other plan, arrangement or understanding, whether now existing or hereafter in effect.

l. Beneficiary Matters. A Participant may designate a Beneficiary to receive benefits due under a Performance Grant, if any, upon the Participant’s death. Designation of a Beneficiary shall be made by execution of a form approved or accepted by the Committee. In the absence of a valid Beneficiary designation, a Participant’s surviving spouse, if any, and if none, the Participant’s estate, shall be the Beneficiary. A Participant may change a prior Beneficiary designation by a subsequent execution of a new Beneficiary designation form. The change in Beneficiary will be effective upon receipt by the Committee. Any payment made to a Beneficiary under this Plan in good faith shall fully discharge the Company and the Dominion Companies from all further obligations with respect to that payment. If the Committee has any doubt as to the proper Beneficiary to receive a payment under this Plan, the Committee shall have the right to withhold such payment until the matter is fully adjudicated. In making any payment to or for the benefit of any minor or an incompetent Participant or Beneficiary, the administrator, in its sole and absolute discretion, may make a distribution to a legal or natural guardian or other relative of a minor or court-appointed representative of such incompetent. Alternatively, it may make a payment to any adult with whom the minor or incompetent temporarily or permanently resides. The receipt by a guardian, representative, relative or other person shall be a complete discharge of the Company and the Dominion Companies’ obligations under the Plan. The Company shall have no responsibility to see to the proper application of any payment so made. The Plan shall be binding on all successors and assigns of a Participant, including, without limitation, the estate of such participant and the executor, administrator or trustee of such estate, or any receiver or trustee in bankruptcy or representative of the Participant’s creditors.

m. Deferred Payouts. If a Participant who has become entitled to a payout of their Performance Grant has previously elected to defer receipt of all or a portion of the Performance Grant under the Dominion Energy, Inc. Deferred Compensation Plan (“Deferred Compensation Plan”), then, in lieu of a cash payment to the Participant as otherwise described in the Plan, the payout amount of the Performance Grant (or applicable portion thereof) will be credited to the Participant’s book-entry account under the Deferred Compensation Plan as of the date such amount would otherwise have been paid to the Participant.

n. Unfunded Plan. Unless otherwise determined by the Committee, the Plan shall be unfunded and shall not create (or be construed to create) a trust or a separate fund or funds. The Plan shall not establish any fiduciary relationship between the Company and any Participant or other person. To the extent any person holds any rights by virtue of a Performance Grant granted under the Plan, such rights (unless otherwise determined by the Committee) shall be no greater than the rights of an unsecured general creditor of the Company.

EXHIBIT A

DOMINION ENERGY, INC.

2023 PERFORMANCE GRANT PLAN

PERFORMANCE CRITERIA

Two-Year Relative TSR Performance

Two-Year Relative Total Shareholder Return Performance (“Two-Year Relative TSR Performance”) will determine forty percent (40%) of the Target Amount (“TSR Percentage”). Two-Year Relative TSR Performance is defined below. The percentage of the TSR Percentage that will be paid out, if any, is based on the following table:

To the extent that the Company’s Two-Year Relative TSR Performance ranks in a percentile between the 25th and 85th percentile in the table above, then the TSR Percentage payout will be interpolated between the corresponding TSR Percentage payout set forth above.

Two-Year Relative TSR Performance will be measured based on where the Company’s total shareholder return during the Two-Year Performance Period ranks in relation to the total shareholder returns of the companies that are members of the Company’s compensation peer group as of the Date of Grant as set forth below (the “Comparison Companies”):

Two-Year Performance Period means January 1, 2024 through December 31, 2025.

The Comparison Companies shall be adjusted during the Two-Year Performance Period as follows:

(i) In the event of a merger, acquisition or business combination transaction of a Comparison Company with or by another Comparison Company, effective upon the public announcement of the transaction, the surviving entity shall remain a Comparison Company and the non-surviving entity shall cease to be a Comparison Company (provided that, if the proposed transaction is subsequently terminated before the Two-Year Relative TSR Performance is calculated, then the non-surviving company shall be retroactively reinstated as a Comparison Company);

(ii) If it is publicly announced that a Comparison Company will be acquired by another company that is not a Comparison Company, or in the event a “going private transaction” is publicly announced where the Comparison Company will not be the surviving entity or will otherwise no longer be publicly traded, the company shall cease to be a Comparison Company as of the date such announcement is made (provided that, if the proposed transaction is subsequently terminated before the Two-Year Relative TSR Performance is calculated, then the company shall be retroactively reinstated as a Comparison Company);

(iii) In the event of a spinoff, divestiture, or sale of a substantial portion of assets of a Comparison Company, the Comparison Company shall no longer be a Comparison Company if the company’s reported revenue (in its GAAP accounts) for the four most recently reported quarters ending on or before the last day of the Two-Year Performance Period falls below 40% of Dominion Energy’s reported revenue (in its GAAP accounts) for the four most recently reported quarters on or before the last day of the Two-Year Performance Period; and

(iv) In the event of a bankruptcy of a Comparison Company, such company shall remain a Comparison Company and its stock price will continue to be tracked for purposes of Two-Year Relative TSR Performance. If the company liquidates, it will remain a Comparison Company and its stock price will be reduced to zero for the remaining Two-Year Performance Period.

Total shareholder return consists of the difference between the value of a share of common stock at the beginning (the volume-weighted average price (VWAP) of the first 20 trading days of the Two-Year Performance Period) and end (the VWAP of the last 20 trading days of the Two-Year Performance Period), plus the value of gross dividends paid as if reinvested in stock and other appropriate adjustments for such events as stock splits. For purposes of Two-Year Relative TSR Performance, the total shareholder return of the Company and the Comparison Companies will be calculated using data from Bloomberg or another comparable source. As soon as practicable after the completion of the Two-Year Performance Period, the total shareholder returns of the Comparison Companies will be calculated and ranked from highest to lowest by the Committee. The Company’s total shareholder return will then be ranked in terms of which percentile it would have placed in among the Comparison Companies.

NCGC Performance

Non-Carbon Emitting Generation Capacity Performance (“NCGC Performance”) will determine ten percent (10%) of the Target Amount (“NCGC Performance Percentage”). NCGC Performance is defined below. The percentage of the NCGC Performance Percentage that will be paid out, if any, is based on the following table:

To the extent the Company’s NCGC Performance is greater than the Minimum and less than the Target Range, or greater than the Target Range but less than the Maximum, the NCGC Performance Percentage payout will be interpolated between the corresponding Percentage Payout of NCGC Performance Percentage ranges set forth above.

NCGC Performance means the Company’s Non-Carbon Emitting Generation Capacity Percentage as determined as of the last day of the Performance Period.

Non-Carbon Emitting Generation Capacity Percentage means the percentage determined by dividing the Company’s Non-Carbon Emitting Generation Capacity by its Net Generation Capacity.

The Company’s Non-Carbon Emitting Generation Capacity means its wind, solar, nuclear and conventional hydro generation capacity.

The Company’s Net Generation Capacity means its total generation capacity minus pumped hydro/battery storage.

Capacity means megawatt (MW) capacity from (x) in-service facilities as of the last day of the Performance Period plus (y) facilities proposed to be in-service by the last day of the Performance Period and submitted for regulatory approval (even if subsequently rejected). A facility will only be counted once in any given Performance Period.

Megawatts (MWs) that are not intermittent resources are defined as installed summer maximum capability (capacity). MWs for intermittent renewable resources are defined as the original installed or proposed nameplate capacity. MWs included in the calculation will be those owned by or serving Dominion Energy regulated entities (by contract or agreement), and include the following: Cost of Service, Ringfence Projects, Power Purchase Agreements (PPAs), Distributed Energy Resources (DERs), and Behind the Meter Generation (Non-utility generators). Detailed tracking will be in place to ensure that MW are not counted more than once in the calculation. This NCGC goal, and the associated Percentage Payout, is subject to possible revisions or adjustments, at the Committee’s sole discretion, if generation retirements do not occur as currently planned during the Performance Period.

AMENDMENT TO

DOMINION ENERGY, INC.

2023 PERFORMANCE GRANT PLAN

Notwithstanding any contrary terms of the 2023 Performance Grant Plan, the Company’s Chief Executive Officer, Robert M. Blue, shall not be eligible to receive the Performance Adder described in Section 6(a) with respect to his 2023 Performance Grant.

AMENDMENT TO

DOMINION ENERGY, INC.

2023 PERFORMANCE GRANT PLAN

Notwithstanding any contrary terms of the 2023 Performance Grant Plan, the tables in Section 6(a) and Exhibit A regarding relative TSR performance with respect to the 2023 Performance Grant awarded to the Company’s Chief Executive Officer, Robert M. Blue, are amended in their entirety to read as follows: