# EDGAR Filing Document

**Accession Number:** 0001013871
**File Stem:** 0001104659-26-023622
**Filing Date:** 2026-3
**Character Count:** 34664
**Document Hash:** 526ec7a0d281a264f60e1e0713686c92
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-26-023622.hdr.sgml**: 20260304

**ACCESSION NUMBER**: 0001104659-26-023622

**CONFORMED SUBMISSION TYPE**: SCHEDULE 13G/A

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20260304

**DATE AS OF CHANGE**: 20260304

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** NRG ENERGY, INC.
- **CENTRAL INDEX KEY:** 0001013871
- **STANDARD INDUSTRIAL CLASSIFICATION:** ELECTRIC SERVICES [4911]
- **ORGANIZATION NAME:** 01 Energy & Transportation
- **EIN:** 411724239
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13G/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-59253
- **FILM NUMBER:** 26723387

**BUSINESS ADDRESS:**
- **STREET 1:** 910 LOUISIANA STREET
- **CITY:** HOUSTON
- **STATE:** TX
- **ZIP:** 77002
- **BUSINESS PHONE:** 713-537-3000

**MAIL ADDRESS:**
- **STREET 1:** 910 LOUISIANA STREET
- **CITY:** HOUSTON
- **STATE:** TX
- **ZIP:** 77002

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** NRG ENERGY INC
- **DATE OF NAME CHANGE:** 19960509
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Lightning Power Holdings, LLC
- **CENTRAL INDEX KEY:** 0002108646

**ORGANIZATION NAME:**
- **EIN:** 994119050
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231
- **LEGAL ENTITY IDENTIFIER:** 2549005S14Z6Y1UA9438

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13G/A

**BUSINESS ADDRESS:**
- **STREET 1:** 250 W 55TH STREET, 31ST FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10019
- **BUSINESS PHONE:** 2126153456

**MAIL ADDRESS:**
- **STREET 1:** 250 W 55TH STREET, 31ST FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10019

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

## SCHEDULE 13G

### Under the Securities Exchange Act of 1934

**(Amendment No. 1)**

**Issuer:** NRG ENERGY, INC.

**Title of Class of Securities:** Common Stock, par value $0.01 per share

**CUSIP Number:** 629377508

**Date of Event Which Requires Filing of this Statement:** 03/04/2026

**Check the appropriate box to designate the rule pursuant to which this Schedule is filed:**

- [ ] Rule 13d-1(b)

- [x] Rule 13d-1(c)

- [ ] Rule 13d-1(d)

---

| 1. | Names of Reporting Persons<br>Lightning Power Holdings, LLC | Names of Reporting Persons<br>Lightning Power Holdings, LLC |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>DE | Citizenship or Place of Organization<br>DE |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>6371100.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>6371100.00 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>6371100.00 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>6371100.00 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>3.00% | Percent of Class Represented by Amount in Row (9)<br>3.00% |
| 12. | Type of Reporting Person (See Instructions)<br>OO | Type of Reporting Person (See Instructions)<br>OO |

**Comment for Type of Reporting Person:** (1) Pursuant to the Voting Trust Agreement (discussed below), Lightning Power Holdings, LLC deposited 2,589,007 shares of Common Stock in the Trust (as defined below) and granted to the Trustee (as defined below), subject to certain exceptions, voting rights with respect to such shares.  As a result, the Trustee has the right to direct the voting of such shares of Common Stock beneficially owned by Lightning Power Holdings, LLC.

(2) The percent of class represented by the amount in Row (11) is based on 212,376,200 shares outstanding after the completion of the secondary offering of the Issuer's Common Stock and the Share Repurchase (as defined herein), as reported in the Issuer's Prospectus, dated March 2, 2026, filed with the Securities and Exchange Commission ("SEC") on March 3, 2026 (without giving effect to the underwriters' option to purchase additional shares of Common Stock).

---

| 1. | Names of Reporting Persons<br>Fund III Lightning Holdings, LLC | Names of Reporting Persons<br>Fund III Lightning Holdings, LLC |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>DE | Citizenship or Place of Organization<br>DE |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>6371100.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>6371100.00 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>6371100.00 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>6371100.00 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>3.00% | Percent of Class Represented by Amount in Row (9)<br>3.00% |
| 12. | Type of Reporting Person (See Instructions)<br>OO | Type of Reporting Person (See Instructions)<br>OO |

**Comment for Type of Reporting Person:** (1) Pursuant to the Voting Trust Agreement, Lightning Power Holdings, LLC deposited 2,589,007 shares of Common Stock in the Trust and granted to the Trustee, subject to certain exceptions, voting rights with respect to such shares.  As a result, the Trustee has the right to direct the voting of such shares of Common Stock (a) beneficially owned by Lightning Power Holdings, LLC and (b) indirectly held by Fund III Lightning Holdings, LLC, who may be deemed to share the right to direct the disposition of all such shares.

(2) The percent of class represented by the amount in Row (11) is based on 212,376,200 shares outstanding after the completion of the secondary offering of the Issuer's Common Stock and the Share Repurchase (as defined herein), as reported in the Issuer's Prospectus, dated March 2, 2026, filed with the SEC on March 3, 2026 (without giving effect to the underwriters' option to purchase additional shares of Common Stock).

---

| 1. | Names of Reporting Persons<br>Granite Energy, LLC | Names of Reporting Persons<br>Granite Energy, LLC |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>DE | Citizenship or Place of Organization<br>DE |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>6371100.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>6371100.00 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>6371100.00 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>6371100.00 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>3.00% | Percent of Class Represented by Amount in Row (9)<br>3.00% |
| 12. | Type of Reporting Person (See Instructions)<br>OO | Type of Reporting Person (See Instructions)<br>OO |

**Comment for Type of Reporting Person:** (1) Pursuant to the Voting Trust Agreement, Lightning Power Holdings, LLC deposited 2,589,007 shares of Common Stock in the Trust and granted to the Trustee, subject to certain exceptions, voting rights with respect to such shares.  As a result, the Trustee has the right to direct the voting of such shares of Common Stock (a) beneficially owned by Lightning Power Holdings, LLC and (b) indirectly held by Granite Energy, LLC, who may be deemed to share the right to direct the disposition of all such shares.

(2) The percent of class represented by the amount in Row (11) is based on 212,376,200 shares outstanding after the completion of the secondary offering of the Issuer's Common Stock and the Share Repurchase (as defined herein), as reported in the Issuer's Prospectus, dated March 2, 2026, filed with the SEC on March 3, 2026 (without giving effect to the underwriters' option to purchase additional shares of Common Stock).

---

| 1. | Names of Reporting Persons<br>Granite Energy Holdings, LLC | Names of Reporting Persons<br>Granite Energy Holdings, LLC |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>DE | Citizenship or Place of Organization<br>DE |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>6371100.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>6371100.00 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>6371100.00 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>6371100.00 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>3.00% | Percent of Class Represented by Amount in Row (9)<br>3.00% |
| 12. | Type of Reporting Person (See Instructions)<br>OO | Type of Reporting Person (See Instructions)<br>OO |

**Comment for Type of Reporting Person:** (1) Pursuant to the Voting Trust Agreement, Lightning Power Holdings, LLC deposited 2,589,007 shares of Common Stock in the Trust and granted to the Trustee, subject to certain exceptions, voting rights with respect to such shares.  As a result, the Trustee has the right to direct the voting of such shares of Common Stock (a) beneficially owned by Lightning Power Holdings, LLC and (b) indirectly held by Granite Energy Holdings, LLC, who may be deemed to share the right to direct the disposition of all such shares.

(2) The percent of class represented by the amount in Row (11) is based on 212,376,200 shares outstanding after the completion of the secondary offering of the Issuer's Common Stock and the Share Repurchase (as defined herein), as reported in the Issuer's Prospectus, dated March 2, 2026, filed with the SEC on March 3, 2026 (without giving effect to the underwriters' option to purchase additional shares of Common Stock).

---

| 1. | Names of Reporting Persons<br>LS Power Equity Partners III, L.P. | Names of Reporting Persons<br>LS Power Equity Partners III, L.P. |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>DE | Citizenship or Place of Organization<br>DE |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>6371100.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>6371100.00 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>6371100.00 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>6371100.00 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>3.00% | Percent of Class Represented by Amount in Row (9)<br>3.00% |
| 12. | Type of Reporting Person (See Instructions)<br>PN | Type of Reporting Person (See Instructions)<br>PN |

**Comment for Type of Reporting Person:** (1) Pursuant to the Voting Trust Agreement, Lightning Power Holdings, LLC deposited 2,589,007 shares of Common Stock in the Trust and granted to the Trustee, subject to certain exceptions, voting rights with respect to such shares.  As a result, the Trustee has the right to direct the voting of such shares of Common Stock (a) beneficially owned by Lightning Power Holdings, LLC and (b) indirectly held by LS Power Equity Partners III, L.P., who may be deemed to share the right to direct the disposition of all such shares.

(2) The percent of class represented by the amount in Row (11) is based on 212,376,200 shares outstanding after the completion of the secondary offering of the Issuer's Common Stock and the Share Repurchase (as defined herein), as reported in the Issuer's Prospectus, dated March 2, 2026, filed with the SEC on March 3, 2026 (without giving effect to the underwriters' option to purchase additional shares of Common Stock).

---

| 1. | Names of Reporting Persons<br>LS Power Partners III, L.P. | Names of Reporting Persons<br>LS Power Partners III, L.P. |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>DE | Citizenship or Place of Organization<br>DE |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>6371100.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>6371100.00 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>6371100.00 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>6371100.00 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>3.00% | Percent of Class Represented by Amount in Row (9)<br>3.00% |
| 12. | Type of Reporting Person (See Instructions)<br>PN | Type of Reporting Person (See Instructions)<br>PN |

**Comment for Type of Reporting Person:** (1) Pursuant to the Voting Trust Agreement, Lightning Power Holdings, LLC deposited 2,589,007 shares of Common Stock in the Trust and granted to the Trustee, subject to certain exceptions, voting rights with respect to such shares.  As a result, the Trustee has the right to direct the voting of such shares of Common Stock (a) beneficially owned by Lightning Power Holdings, LLC and (b) indirectly held by LS Power Partners III, L.P., who may be deemed to share the right to direct the disposition of all such shares.

(2) The percent of class represented by the amount in Row (11) is based on 212,376,200 shares outstanding after the completion of the secondary offering of the Issuer's Common Stock and the Share Repurchase (as defined herein), as reported in the Issuer's Prospectus, dated March 2, 2026, filed with the SEC on March 3, 2026 (without giving effect to the underwriters' option to purchase additional shares of Common Stock).

---

| 1. | Names of Reporting Persons<br>LS Power Fund III G.P., LLC | Names of Reporting Persons<br>LS Power Fund III G.P., LLC |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>DE | Citizenship or Place of Organization<br>DE |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>6371100.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>6371100.00 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>6371100.00 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>6371100.00 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>3.00% | Percent of Class Represented by Amount in Row (9)<br>3.00% |
| 12. | Type of Reporting Person (See Instructions)<br>OO | Type of Reporting Person (See Instructions)<br>OO |

**Comment for Type of Reporting Person:** (1) Pursuant to the Voting Trust Agreement, Lightning Power Holdings, LLC deposited 2,589,007 shares of Common Stock in the Trust and granted to the Trustee, subject to certain exceptions, voting rights with respect to such shares.  As a result, the Trustee has the right to direct the voting of such shares of Common Stock (a) beneficially owned by Lightning Power Holdings, LLC and (b) indirectly held by LS Power Fund III G.P., LLC, who may be deemed to share the right to direct the disposition of all such shares.

(2) The percent of class represented by the amount in Row (11) is based on 212,376,200 shares outstanding after the completion of the secondary offering of the Issuer's Common Stock and the Share Repurchase (as defined herein), as reported in the Issuer's Prospectus, dated March 2, 2026, filed with the SEC on March 3, 2026 (without giving effect to the underwriters' option to purchase additional shares of Common Stock).

---

| 1. | Names of Reporting Persons<br>LS Power Equity Advisors, LLC | Names of Reporting Persons<br>LS Power Equity Advisors, LLC |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>DE | Citizenship or Place of Organization<br>DE |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>8120731.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>8120731.00 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>8120731.00 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>8120731.00 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>3.82% | Percent of Class Represented by Amount in Row (9)<br>3.82% |
| 12. | Type of Reporting Person (See Instructions)<br>OO | Type of Reporting Person (See Instructions)<br>OO |

**Comment for Type of Reporting Person:** (1) Pursuant to the Voting Trust Agreement, Lightning Power Holdings, LLC and the other Sellers (as defined below), deposited 2,589,007 and 710,993 shares of Common Stock, respectively, in the Trust and granted to the Trustee, subject to certain exceptions, voting rights with respect to such shares.  As a result, the Trustee has the right to direct the voting of such shares of Common Stock held indirectly by LS Power Equity Advisors, LLC, who may be deemed to share the right to direct the disposition of all such shares.

(2) The percent of class represented by the amount in Row (11) is based on 212,376,200 shares outstanding after the completion of the secondary offering of the Issuer's Common Stock and the Share Repurchase (as defined herein), as reported in the Issuer's Prospectus, dated March 2, 2026, filed with the SEC on March 3, 2026 (without giving effect to the underwriters' option to purchase additional shares of Common Stock).

---

| 1. | Names of Reporting Persons<br>David Nanus | Names of Reporting Persons<br>David Nanus |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>X1 | Citizenship or Place of Organization<br>X1 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>8120731.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>8120731.00 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>8120731.00 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>8120731.00 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>3.82% | Percent of Class Represented by Amount in Row (9)<br>3.82% |
| 12. | Type of Reporting Person (See Instructions)<br>IN | Type of Reporting Person (See Instructions)<br>IN |

**Comment for Type of Reporting Person:** (1) Pursuant to the Voting Trust Agreement, Lightning Power Holdings, LLC and the other Sellers, deposited 2,589,007 and 710,993 shares of Common Stock, respectively, in the Trust and granted to the Trustee, subject to certain exceptions, voting rights with respect to such shares.  As a result, the Trustee has the right to direct the voting of such shares of Common Stock deemed held indirectly by Mr. Nanus, President of LS Power Equity Advisors, LLC, who may be deemed to share the right to direct the disposition of all such shares.

(2) The percent of class represented by the amount in Row (11) is based on 212,376,200 shares outstanding after the completion of the secondary offering of the Issuer's Common Stock and the Share Repurchase (as defined herein), as reported in the Issuer's Prospectus, dated March 2, 2026, filed with the SEC on March 3, 2026 (without giving effect to the underwriters' option to purchase additional shares of Common Stock).

---

**Item 1(a). Name of Issuer:**
NRG ENERGY, INC.

**Item 1(b). Address of Issuer's Principal Executive Offices:**
910 Louisiana Street, Houston, TX, 77002

**Item 2(a). Name of Person Filing:**
This statement is being filed jointly by the following (each, a "Reporting Person," and collectively, the "Reporting Persons"):

Lightning Power Holdings, LLC, a Delaware limited liability company
Fund III Lightning Holdings, LLC, a Delaware limited liability company
Granite Energy, LLC, a Delaware limited liability company
Granite Energy Holdings, LLC, a Delaware limited liability company
LS Power Equity Partners III, L.P., a Delaware limited partnership
LS Power Partners III, L.P., a Delaware limited partnership
LS Power Fund III G.P., LLC, a Delaware limited liability company
LS Power Equity Advisors, LLC, a Delaware limited liability company and SEC-registered investment adviser.
David Nanus

**Item 2(b). Address of Principal Business Office:**
The principal business address of each of the Reporting Persons is 250 W 55th Street, 31st  Floor, New York, New York 10019.

**Item 2(c). Citizenship:**
Each of the Reporting Persons that are entities are organized under the laws of the State of Delaware. David Nanus is a citizen of the United States.

**Item 2(d). Title of Class of Securities:**
Common Stock, par value $0.01 per share

**Item 2(e). CUSIP Number:**
629377508

**Item 3. If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:**

(a) [ ] Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o).

(b) [ ] Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).

(c) [ ] Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c).

(d) [ ] Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8).

(e) [ ] An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);

(f) [ ] An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);

(g) [ ] A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);

(h) [ ] A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(i) [ ] A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);

(j) [ ] A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), if filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:

(k) [ ] Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).

**Item 4. Ownership:**

**(a) Amount beneficially owned:**

The information required by Item 4(a) is set forth in Rows 9 and 11 of the cover pages hereto for each Reporting Person and is incorporated herein by reference for each Reporting Person.
On March 4, 2026 Lightning Power Holdings, LLC ("Lightning") and Thunder Generation, LLC, and CCS Power Holdings, LLC (together the "Other Holders") sold an aggregate 14,300,000 shares (11,219,029 and 3,080,971 shares, by Lightning and the Other Holders respectively), of Common Stock at a public offering price of $164 per share in an underwritten registered secondary offering (the "Secondary Offering"). In addition, on March 4, 2026, the Issuer repurchased 1,829,269 aggregate shares of Common Stock (1,435,148 and 394,120 shares from Lightning and the Other Holders, respectively), in a privately negotiated transaction (the "Share Repurchase"), at a price equal to the $164 per share public offering price in the Secondary Offering. In connection with the Secondary Offering, Lightning and the Other Holders granted the underwriters an option to purchase up to 2,145,000 additional shares of Common Stock, which option has not yet been exercised.
LS Power Equity Advisors, LLC is the investment advisor to LS Power Equity Partners III, L.P., which may be deemed to beneficially own the shares held by Lightning. LS Power Equity Advisors, LLC, is the investment advisor to LS Power Equity Partners IV L.P., which may be deemed to beneficially own the shares held by the Other Holders. David Nanus is the President of LS Power Equity Advisors, LLC. As a result, each of LS Power Equity Advisors, LLC and Mr. Nanus may be deemed to share beneficial ownership of the shares held by Lightning and the Other Holders. Mr. Nanus disclaims beneficial ownership of all such shares.
The number of securities reported as beneficially owned herein includes 2,589,007 shares owned by Lightning and includes 710,993 shares owned by the Other Sellers, representing an aggregate of 3,300,000 shares, that have been deposited in a voting trust ("Voting Trust") pursuant to the Amended and Restated Voting Trust Agreement (the "Voting Trust Agreement") dated January 30, 2026, among Wilmington Savings Fund Society, FSB (the "Trustee"), Lightning, the Other Sellers, and the Issuer. None of the shares included in the Secondary Offering were held in the Voting Trust.

**(b) Percent of class:**

The information required by Item 4(b) is set forth in Rows 9 and 11 of the cover pages hereto for each Reporting Person and is incorporated herein by reference for each Reporting Person.
The percent of class represented by the amount in Row (11) is based on 212,376,200 shares outstanding after the completion of the secondary offering of the Issuer's Common Stock and the Share Repurchase (as defined herein), as reported in the Issuer's Prospectus, dated March 2, 2026, filed with the SEC on March 3, 2026 (without giving effect to the underwriters' option to purchase additional shares of Common Stock).

**(c) Number of shares as to which the person has:**

**(i) Sole power to vote or to direct the vote:**

The information required by Item 4(c)(i) is set forth in Row 5 of the cover pages hereto for each Reporting Person and is incorporated herein by reference for each Reporting Person.

**(ii) Shared power to vote or to direct the vote:**

The information required by Item 4(c)(ii) is set forth in Row 6 of the cover pages hereto for each Reporting Person and is incorporated herein by reference for each Reporting Person.

**(iii) Sole power to dispose or to direct the disposition of:**

The information required by Item 4(c)(iii) is set forth in Row 7 of the cover pages hereto for each Reporting Person and is incorporated herein by reference for each Reporting Person.

**(iv) Shared power to dispose or to direct the disposition of:**

The information required by Item 4(c)(iv) is set forth in Row 8 of the cover pages hereto for each Reporting Person and is incorporated herein by reference for each Reporting Person.

**Item 5. Ownership of Five Percent or Less of a Class.**

[ ] If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following.

**Item 6. Ownership of More than 5 Percent on Behalf of Another Person.**

Not Applicable

**Item 7. Identification and Classification of the Subsidiary**

Not Applicable

**Item 8. Identification and Classification of Members of the Group**

Not Applicable

**Item 9. Notice of Dissolution of Group**

Not Applicable

**Item 10. Certification:**

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.

### SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Lightning Power Holdings, LLC**

**Date:** 03/04/2026

**By:** /s/ Jeffrey Wade

**Name & Title:** Jeffrey Wade/Chief Compliance Officer

**Fund III Lightning Holdings, LLC**

**Date:** 03/04/2026

**By:** /s/ Jeffrey Wade

**Name & Title:** Jeffrey Wade/Chief Compliance Officer

**Granite Energy, LLC**

**Date:** 03/04/2026

**By:** /s/ Jeffrey Wade

**Name & Title:** Jeffrey Wade/Chief Compliance Officer

**Granite Energy Holdings, LLC**

**Date:** 03/04/2026

**By:** /s/ Jeffrey Wade

**Name & Title:** Jeffrey Wade/Chief Compliance Officer

**LS Power Equity Partners III, L.P.**

**Date:** 03/04/2026

**By:** /s/ Jeffrey Wade

**Name & Title:** Jeffrey Wade/Chief Compliance Officer

**LS Power Partners III, L.P.**

**Date:** 03/04/2026

**By:** /s/ Jeffrey Wade

**Name & Title:** Jeffrey Wade/Chief Compliance Officer

**LS Power Fund III G.P., LLC**

**Date:** 03/04/2026

**By:** /s/ Jeffrey Wade

**Name & Title:** Jeffrey Wade/Chief Compliance Officer

**LS Power Equity Advisors, LLC**

**Date:** 03/04/2026

**By:** /s/ Jeffrey Wade

**Name & Title:** Jeffrey Wade/Chief Compliance Officer

**David Nanus**

**Date:** 03/04/2026

**By:** /s/ David Nanus

**Name & Title:** David Nanus