NPWR

SEC source: 0001104659-25-101628 · tm2529224-2_4seq1.xml · nonDerivative · entry 1

8 Rivers Capital, LLC · CIK 0001981100 · 10% owner

BEAUCHAMP DAMIAN R. · CIK 0001973442 · 10% owner

Beauchamp Cynda · CIK 0002079418 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · By: NPEH, LLC

Disclosed balance after: 3,562,400

F1 · price: The price reported reflects the weighted average sales price. The shares of Class A Common Stock were sold in multiple trades at prices ranging from $3.51 to $3.72. NPEH, LLC ("NPEH") will provide upon request to the SEC, the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

F4 · ownership.nature: As manager and holder of approximately 91.4% of the outstanding equity in NPEH, 8 Rivers Capital, LLC ("8 Rivers") may be deemed to be a beneficial owner of the securities directly owned by NPEH. 8 Rivers disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that 8 Rivers is the beneficial owner of such securities for purposes of Section 16 or otherwise.

F5 · ownership.nature: Damian R. Beauchamp ("Mr. Beauchamp") and Cynda Beauchamp ("Mrs. Beauchamp") are married and each independently indirectly owns approximately 34.2% of 8 Rivers. Accordingly, each may be deemed the indirect beneficial owner of the securities owned by NPEH to the extent of his or her pecuniary interest therein. Mr. and Mrs. Beauchamp disclaim beneficial ownership of any such securities, except to the extent of his or her pecuniary interest therein, if any, and this report shall not be deemed an admission that Mr. or Mrs. Beauchamp is the beneficial owner of such securities for purposes of Section 16 or otherwise.

SEC source: 0001104659-25-100173 · tm2528899-1_4seq1.xml · nonDerivative · entry 5

8 Rivers Capital, LLC · CIK 0001981100 · 10% owner

BEAUCHAMP DAMIAN R. · CIK 0001973442 · 10% owner

Beauchamp Cynda · CIK 0002079418 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · By: NPEH, LLC

Disclosed balance after: 3,763,400

F5 · price: The price reported reflects the weighted average sales price. The shares of Class A Common Stock were sold in multiple trades at prices ranging from $4.50 to $4.83. NPEH will provide upon request to the SEC, the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

F6 · ownership.nature: As manager and holder of approximately 91.4% of the outstanding equity in NPEH, 8 Rivers Capital, LLC ("8 Rivers") may be deemed to be a beneficial owner of the securities directly owned by NPEH. 8 Rivers disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that 8 Rivers is the beneficial owner of such securities for purposes of Section 16 or otherwise.

F7 · ownership.nature: Damian Beauchamp ("Mr. Beauchamp") and Cynda Beauchamp ("Mrs. Beauchamp") are married and each independently indirectly owns approximately 34.2% of 8 Rivers. Accordingly, each may be deemed the indirect beneficial owner of the securities owned by NPEH to the extent of his or her pecuniary interest therein. Mr. and Mrs. Beauchamp disclaim beneficial ownership of these securities except to the extent of his or her pecuniary interest therein.

SEC source: 0001104659-25-100174 · tm2528932-1_4seq1.xml · nonDerivative · entry 5

NPEH, LLC · CIK 0001981772 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 3,763,400

F5 · price: The price reported reflects the weighted average sales price. The shares of Class A Common Stock were sold in multiple trades at prices ranging from $4.50 to $4.83. NPEH will provide upon request to the SEC, the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

SEC source: 0001104659-25-100173 · tm2528899-1_4seq1.xml · nonDerivative · entry 4

8 Rivers Capital, LLC · CIK 0001981100 · 10% owner

BEAUCHAMP DAMIAN R. · CIK 0001973442 · 10% owner

Beauchamp Cynda · CIK 0002079418 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · By: NPEH, LLC

Disclosed balance after: 3,777,359

F4 · price: The price reported reflects the weighted average sales price. The shares of Class A Common Stock were sold in multiple trades at prices ranging from $4.85 to $4.925. NPEH will provide upon request to the SEC, the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

F6 · ownership.nature: As manager and holder of approximately 91.4% of the outstanding equity in NPEH, 8 Rivers Capital, LLC ("8 Rivers") may be deemed to be a beneficial owner of the securities directly owned by NPEH. 8 Rivers disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that 8 Rivers is the beneficial owner of such securities for purposes of Section 16 or otherwise.

F7 · ownership.nature: Damian Beauchamp ("Mr. Beauchamp") and Cynda Beauchamp ("Mrs. Beauchamp") are married and each independently indirectly owns approximately 34.2% of 8 Rivers. Accordingly, each may be deemed the indirect beneficial owner of the securities owned by NPEH to the extent of his or her pecuniary interest therein. Mr. and Mrs. Beauchamp disclaim beneficial ownership of these securities except to the extent of his or her pecuniary interest therein.

SEC source: 0001104659-25-100173 · tm2528899-1_4seq1.xml · nonDerivative · entry 3

8 Rivers Capital, LLC · CIK 0001981100 · 10% owner

BEAUCHAMP DAMIAN R. · CIK 0001973442 · 10% owner

Beauchamp Cynda · CIK 0002079418 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · By: NPEH, LLC

Disclosed balance after: 3,900,000

F3 · price: The price reported reflects the weighted average sales price. The shares of Class A Common Stock were sold in multiple trades at prices ranging from $4.67 to $4.93. NPEH will provide upon request to the SEC, the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

F6 · ownership.nature: As manager and holder of approximately 91.4% of the outstanding equity in NPEH, 8 Rivers Capital, LLC ("8 Rivers") may be deemed to be a beneficial owner of the securities directly owned by NPEH. 8 Rivers disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that 8 Rivers is the beneficial owner of such securities for purposes of Section 16 or otherwise.

F7 · ownership.nature: Damian Beauchamp ("Mr. Beauchamp") and Cynda Beauchamp ("Mrs. Beauchamp") are married and each independently indirectly owns approximately 34.2% of 8 Rivers. Accordingly, each may be deemed the indirect beneficial owner of the securities owned by NPEH to the extent of his or her pecuniary interest therein. Mr. and Mrs. Beauchamp disclaim beneficial ownership of these securities except to the extent of his or her pecuniary interest therein.

SEC source: 0001104659-25-100174 · tm2528932-1_4seq1.xml · nonDerivative · entry 4

NPEH, LLC · CIK 0001981772 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 3,777,359

F4 · price: The price reported reflects the weighted average sales price. The shares of Class A Common Stock were sold in multiple trades at prices ranging from $4.85 to $4.925. NPEH will provide upon request to the SEC, the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

SEC source: 0001104659-25-100174 · tm2528932-1_4seq1.xml · nonDerivative · entry 3

NPEH, LLC · CIK 0001981772 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 3,900,000

F3 · price: The price reported reflects the weighted average sales price. The shares of Class A Common Stock were sold in multiple trades at prices ranging from $4.67 to $4.93. NPEH will provide upon request to the SEC, the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

SEC source: 0001104659-25-100173 · tm2528899-1_4seq1.xml · derivative · entry 6

8 Rivers Capital, LLC · CIK 0001981100 · 10% owner

BEAUCHAMP DAMIAN R. · CIK 0001973442 · 10% owner

Beauchamp Cynda · CIK 0002079418 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · By: NPEH, LLC

Disclosed balance after: 22,729,880

Underlying: Class A Common Stock · 4,000,000 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The Class A Units of NET Power Operations LLC are exchangeable into shares of the Issuer's Class A Common Stock or, at the Issuer's election, cash, on a one-for-one basis and have no expiration date. On October 14, 2025, NPEH, LLC ("NPEH") exchanged 4,000,000 Class A Units of NET Power Operations LLC for 4,000,000 shares of the Issuer's Class A Common Stock.

F1 · price: The Class A Units of NET Power Operations LLC are exchangeable into shares of the Issuer's Class A Common Stock or, at the Issuer's election, cash, on a one-for-one basis and have no expiration date. On October 14, 2025, NPEH, LLC ("NPEH") exchanged 4,000,000 Class A Units of NET Power Operations LLC for 4,000,000 shares of the Issuer's Class A Common Stock.

F1 · derivative.exercise_date: The Class A Units of NET Power Operations LLC are exchangeable into shares of the Issuer's Class A Common Stock or, at the Issuer's election, cash, on a one-for-one basis and have no expiration date. On October 14, 2025, NPEH, LLC ("NPEH") exchanged 4,000,000 Class A Units of NET Power Operations LLC for 4,000,000 shares of the Issuer's Class A Common Stock.

F1 · derivative.expiration_date: The Class A Units of NET Power Operations LLC are exchangeable into shares of the Issuer's Class A Common Stock or, at the Issuer's election, cash, on a one-for-one basis and have no expiration date. On October 14, 2025, NPEH, LLC ("NPEH") exchanged 4,000,000 Class A Units of NET Power Operations LLC for 4,000,000 shares of the Issuer's Class A Common Stock.

F3 · ownership.nature: The price reported reflects the weighted average sales price. The shares of Class A Common Stock were sold in multiple trades at prices ranging from $4.67 to $4.93. NPEH will provide upon request to the SEC, the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

SEC source: 0001104659-25-100173 · tm2528899-1_4seq1.xml · nonDerivative · entry 2

8 Rivers Capital, LLC · CIK 0001981100 · 10% owner

BEAUCHAMP DAMIAN R. · CIK 0001973442 · 10% owner

Beauchamp Cynda · CIK 0002079418 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · By: NPEH, LLC

Disclosed balance after: 22,729,880

F2 · price: For each Class A Unit of Net Power Operations LLC, NPEH owns a corresponding share of Class B Common Stock of the Issuer. Upon the exchange of 4,000,000 Class A Units of Net Power Operations LLC, an equal number of shares of Class B Common Stock of the Issuer held by NPEH, which have no economic value, were cancelled.

F6 · ownership.nature: As manager and holder of approximately 91.4% of the outstanding equity in NPEH, 8 Rivers Capital, LLC ("8 Rivers") may be deemed to be a beneficial owner of the securities directly owned by NPEH. 8 Rivers disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that 8 Rivers is the beneficial owner of such securities for purposes of Section 16 or otherwise.

F7 · ownership.nature: Damian Beauchamp ("Mr. Beauchamp") and Cynda Beauchamp ("Mrs. Beauchamp") are married and each independently indirectly owns approximately 34.2% of 8 Rivers. Accordingly, each may be deemed the indirect beneficial owner of the securities owned by NPEH to the extent of his or her pecuniary interest therein. Mr. and Mrs. Beauchamp disclaim beneficial ownership of these securities except to the extent of his or her pecuniary interest therein.

SEC source: 0001104659-25-100173 · tm2528899-1_4seq1.xml · nonDerivative · entry 1

8 Rivers Capital, LLC · CIK 0001981100 · 10% owner

BEAUCHAMP DAMIAN R. · CIK 0001973442 · 10% owner

Beauchamp Cynda · CIK 0002079418 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · By: NPEH, LLC

Disclosed balance after: 4,000,000

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The Class A Units of NET Power Operations LLC are exchangeable into shares of the Issuer's Class A Common Stock or, at the Issuer's election, cash, on a one-for-one basis and have no expiration date. On October 14, 2025, NPEH, LLC ("NPEH") exchanged 4,000,000 Class A Units of NET Power Operations LLC for 4,000,000 shares of the Issuer's Class A Common Stock.

F6 · ownership.nature: As manager and holder of approximately 91.4% of the outstanding equity in NPEH, 8 Rivers Capital, LLC ("8 Rivers") may be deemed to be a beneficial owner of the securities directly owned by NPEH. 8 Rivers disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that 8 Rivers is the beneficial owner of such securities for purposes of Section 16 or otherwise.

F7 · ownership.nature: Damian Beauchamp ("Mr. Beauchamp") and Cynda Beauchamp ("Mrs. Beauchamp") are married and each independently indirectly owns approximately 34.2% of 8 Rivers. Accordingly, each may be deemed the indirect beneficial owner of the securities owned by NPEH to the extent of his or her pecuniary interest therein. Mr. and Mrs. Beauchamp disclaim beneficial ownership of these securities except to the extent of his or her pecuniary interest therein.

SEC source: 0001104659-25-100174 · tm2528932-1_4seq1.xml · derivative · entry 6

NPEH, LLC · CIK 0001981772 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,729,880

Underlying: Class A Common Stock · 4,000,000 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The Class A Units of NET Power Operations LLC are exchangeable into shares of the Issuer's Class A Common Stock or, at the Issuer's election, cash, on a one-for-one basis and have no expiration date. On October 14, 2025, NPEH, LLC ("NPEH") exchanged 4,000,000 Class A Units of NET Power Operations LLC for 4,000,000 shares of the Issuer's Class A Common Stock.

F1 · price: The Class A Units of NET Power Operations LLC are exchangeable into shares of the Issuer's Class A Common Stock or, at the Issuer's election, cash, on a one-for-one basis and have no expiration date. On October 14, 2025, NPEH, LLC ("NPEH") exchanged 4,000,000 Class A Units of NET Power Operations LLC for 4,000,000 shares of the Issuer's Class A Common Stock.

F1 · derivative.exercise_date: The Class A Units of NET Power Operations LLC are exchangeable into shares of the Issuer's Class A Common Stock or, at the Issuer's election, cash, on a one-for-one basis and have no expiration date. On October 14, 2025, NPEH, LLC ("NPEH") exchanged 4,000,000 Class A Units of NET Power Operations LLC for 4,000,000 shares of the Issuer's Class A Common Stock.

F1 · derivative.expiration_date: The Class A Units of NET Power Operations LLC are exchangeable into shares of the Issuer's Class A Common Stock or, at the Issuer's election, cash, on a one-for-one basis and have no expiration date. On October 14, 2025, NPEH, LLC ("NPEH") exchanged 4,000,000 Class A Units of NET Power Operations LLC for 4,000,000 shares of the Issuer's Class A Common Stock.

SEC source: 0001104659-25-100174 · tm2528932-1_4seq1.xml · nonDerivative · entry 2

NPEH, LLC · CIK 0001981772 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,729,880

F2 · price: For each Class A Unit of Net Power Operations LLC, NPEH owns a corresponding share of Class B Common Stock of the Issuer. Upon the exchange of 4,000,000 Class A Units of Net Power Operations LLC, an equal number of shares of Class B Common Stock of the Issuer held by NPEH, which have no economic value, were cancelled.

SEC source: 0001104659-25-100174 · tm2528932-1_4seq1.xml · nonDerivative · entry 1

NPEH, LLC · CIK 0001981772 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,000,000

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The Class A Units of NET Power Operations LLC are exchangeable into shares of the Issuer's Class A Common Stock or, at the Issuer's election, cash, on a one-for-one basis and have no expiration date. On October 14, 2025, NPEH, LLC ("NPEH") exchanged 4,000,000 Class A Units of NET Power Operations LLC for 4,000,000 shares of the Issuer's Class A Common Stock.

SEC source: 0001104659-25-072811 · tm2522100-2_4seq1.xml · derivative · entry 2

SK INC. · CIK 0001947998 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Class A Common Stock · 26,729,880 shares

Expires not disclosed

F2 · derivative.exercise_price: For each Class A Unit of Net Power Operations LLC, NPEH owns one corresponding share of Class B Common Stock of the Issuer. The Class A Units of NET Power Operations LLC are exchangeable (together with the cancellation of a corresponding number of shares of the Issuer's Class B Common Stock) into shares of the Issuer's Class A Common Stock on a one-for-one basis or, at the Issuer's election, cash, and have no expiration date.

F1 · kind: The securities reported in this Form 4 are directly held by NPEH, LLC ("NPEH"), a limited liability company of which the Reporting Person was the indirect majority owner. On July 30, 2025, the Reporting Person sold 100% of the equity interests of each of Tillandsia, Inc. ("Tillandsia"), Areca, Inc. ("Areca") and Chamaedorea, Inc. ("Chamaedoria"). Tillandsia, Areca and Chamaedorea own approximately 18.6%, 25.77% and 24.11%, respectively, of the voting units of 8 Rivers Capital, LLC ("8 Rivers"). 8 Rivers is the manager and owns approximately 91.4% of NPEH.

F1 · price: The securities reported in this Form 4 are directly held by NPEH, LLC ("NPEH"), a limited liability company of which the Reporting Person was the indirect majority owner. On July 30, 2025, the Reporting Person sold 100% of the equity interests of each of Tillandsia, Inc. ("Tillandsia"), Areca, Inc. ("Areca") and Chamaedorea, Inc. ("Chamaedoria"). Tillandsia, Areca and Chamaedorea own approximately 18.6%, 25.77% and 24.11%, respectively, of the voting units of 8 Rivers Capital, LLC ("8 Rivers"). 8 Rivers is the manager and owns approximately 91.4% of NPEH.

F2 · derivative.exercise_date: For each Class A Unit of Net Power Operations LLC, NPEH owns one corresponding share of Class B Common Stock of the Issuer. The Class A Units of NET Power Operations LLC are exchangeable (together with the cancellation of a corresponding number of shares of the Issuer's Class B Common Stock) into shares of the Issuer's Class A Common Stock on a one-for-one basis or, at the Issuer's election, cash, and have no expiration date.

F2 · derivative.expiration_date: For each Class A Unit of Net Power Operations LLC, NPEH owns one corresponding share of Class B Common Stock of the Issuer. The Class A Units of NET Power Operations LLC are exchangeable (together with the cancellation of a corresponding number of shares of the Issuer's Class B Common Stock) into shares of the Issuer's Class A Common Stock on a one-for-one basis or, at the Issuer's election, cash, and have no expiration date.

F1 · ownership.nature: The securities reported in this Form 4 are directly held by NPEH, LLC ("NPEH"), a limited liability company of which the Reporting Person was the indirect majority owner. On July 30, 2025, the Reporting Person sold 100% of the equity interests of each of Tillandsia, Inc. ("Tillandsia"), Areca, Inc. ("Areca") and Chamaedorea, Inc. ("Chamaedoria"). Tillandsia, Areca and Chamaedorea own approximately 18.6%, 25.77% and 24.11%, respectively, of the voting units of 8 Rivers Capital, LLC ("8 Rivers"). 8 Rivers is the manager and owns approximately 91.4% of NPEH.

F2 · ownership.nature: For each Class A Unit of Net Power Operations LLC, NPEH owns one corresponding share of Class B Common Stock of the Issuer. The Class A Units of NET Power Operations LLC are exchangeable (together with the cancellation of a corresponding number of shares of the Issuer's Class B Common Stock) into shares of the Issuer's Class A Common Stock on a one-for-one basis or, at the Issuer's election, cash, and have no expiration date.

SEC source: 0001104659-25-072811 · tm2522100-2_4seq1.xml · nonDerivative · entry 1

SK INC. · CIK 0001947998 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

F1 · kind: The securities reported in this Form 4 are directly held by NPEH, LLC ("NPEH"), a limited liability company of which the Reporting Person was the indirect majority owner. On July 30, 2025, the Reporting Person sold 100% of the equity interests of each of Tillandsia, Inc. ("Tillandsia"), Areca, Inc. ("Areca") and Chamaedorea, Inc. ("Chamaedoria"). Tillandsia, Areca and Chamaedorea own approximately 18.6%, 25.77% and 24.11%, respectively, of the voting units of 8 Rivers Capital, LLC ("8 Rivers"). 8 Rivers is the manager and owns approximately 91.4% of NPEH.

F1 · price: The securities reported in this Form 4 are directly held by NPEH, LLC ("NPEH"), a limited liability company of which the Reporting Person was the indirect majority owner. On July 30, 2025, the Reporting Person sold 100% of the equity interests of each of Tillandsia, Inc. ("Tillandsia"), Areca, Inc. ("Areca") and Chamaedorea, Inc. ("Chamaedoria"). Tillandsia, Areca and Chamaedorea own approximately 18.6%, 25.77% and 24.11%, respectively, of the voting units of 8 Rivers Capital, LLC ("8 Rivers"). 8 Rivers is the manager and owns approximately 91.4% of NPEH.

F1 · ownership.nature: The securities reported in this Form 4 are directly held by NPEH, LLC ("NPEH"), a limited liability company of which the Reporting Person was the indirect majority owner. On July 30, 2025, the Reporting Person sold 100% of the equity interests of each of Tillandsia, Inc. ("Tillandsia"), Areca, Inc. ("Areca") and Chamaedorea, Inc. ("Chamaedoria"). Tillandsia, Areca and Chamaedorea own approximately 18.6%, 25.77% and 24.11%, respectively, of the voting units of 8 Rivers Capital, LLC ("8 Rivers"). 8 Rivers is the manager and owns approximately 91.4% of NPEH.

F2 · ownership.nature: For each Class A Unit of Net Power Operations LLC, NPEH owns one corresponding share of Class B Common Stock of the Issuer. The Class A Units of NET Power Operations LLC are exchangeable (together with the cancellation of a corresponding number of shares of the Issuer's Class B Common Stock) into shares of the Issuer's Class A Common Stock on a one-for-one basis or, at the Issuer's election, cash, and have no expiration date.

SEC source: 0000950170-25-096435 · ownership.xml · nonDerivative · entry 1

SK INC. · CIK 0001947998 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · By: Tillandsia

Disclosed balance after: 0

F1 · shares: On July 15, 2025, Tillandsia, Inc. ("Tillandsia") sold 2,500,000 shares of Class A Common Stock pursuant to a block trade through its placement manager, Citigroup Global Markets Inc., at a price of $2.61 per share.

F2 · shares: As holder of 100.0% of the outstanding equity in Tillandsia, SK Inc. ("SK") may be deemed to be a beneficial owner of the securities directly owned by Tillandsia. SK disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that SK is the beneficial owner of such securities for purposes of Section 16 or otherwise.

F2 · ownership.nature: As holder of 100.0% of the outstanding equity in Tillandsia, SK Inc. ("SK") may be deemed to be a beneficial owner of the securities directly owned by Tillandsia. SK disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that SK is the beneficial owner of such securities for purposes of Section 16 or otherwise.

SEC source: 0001845437-25-000037 · wk-form4_1749172423.xml · nonDerivative · entry 1

Kelliher Joseph T · CIK 0001464551 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 104,381

F1 · shares: Restricted stock units that vest on June 3, 2026, subject to continued service as a director.

SEC source: 0001845437-25-000035 · wk-form4_1749171547.xml · nonDerivative · entry 1

Alexander Ralph · CIK 0001358507 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 104,381

F1 · shares: Restricted stock units that vest on June 3, 2026, subject to continued service as a director.

SEC source: 0001845437-25-000041 · wk-form4_1749173296.xml · nonDerivative · entry 1

Veltmann Alejandra · CIK 0001564633 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 104,381

F1 · shares: Restricted stock units that vest on June 3, 2026, subject to continued service as a director.

SEC source: 0001845437-25-000039 · wk-form4_1749172849.xml · nonDerivative · entry 1

PETERSON CAROL R. · CIK 0001973456 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 104,381

F1 · shares: Restricted stock units that vest on June 3, 2026, subject to continued service as a director.

SEC source: 0001845437-25-000033 · wk-form4_1749086077.xml · derivative · entry 2

Horstman Marc · CIK 0002070734 · Chief Operating Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 74,766

Underlying: Class A Common Stock · 74,766 shares

Expires not disclosed

F2 · derivative.exercise_price: The Reporting Person will receive a number of shares of Class A common stock equal to 50% of the number of PSUs upon attainment of a 10% compound annual growth rate ("CAGR") of the 30-day volume weighted average price ("VWAP") of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025. The Reporting Person will receive a number of shares of Class A common stock equal to 100% of the number of PSUs upon attainment of a 12% CAGR of the VWAP of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025. The Reporting Person will receive a number of shares of Class A common stock equal to 200% of the number of PSUs upon attainment of a 15% CAGR of the VWAP of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025.

F2 · derivative.exercise_date: The Reporting Person will receive a number of shares of Class A common stock equal to 50% of the number of PSUs upon attainment of a 10% compound annual growth rate ("CAGR") of the 30-day volume weighted average price ("VWAP") of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025. The Reporting Person will receive a number of shares of Class A common stock equal to 100% of the number of PSUs upon attainment of a 12% CAGR of the VWAP of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025. The Reporting Person will receive a number of shares of Class A common stock equal to 200% of the number of PSUs upon attainment of a 15% CAGR of the VWAP of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025.

F2 · derivative.expiration_date: The Reporting Person will receive a number of shares of Class A common stock equal to 50% of the number of PSUs upon attainment of a 10% compound annual growth rate ("CAGR") of the 30-day volume weighted average price ("VWAP") of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025. The Reporting Person will receive a number of shares of Class A common stock equal to 100% of the number of PSUs upon attainment of a 12% CAGR of the VWAP of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025. The Reporting Person will receive a number of shares of Class A common stock equal to 200% of the number of PSUs upon attainment of a 15% CAGR of the VWAP of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025.

SEC source: 0001845437-25-000033 · wk-form4_1749086077.xml · derivative · entry 1

Horstman Marc · CIK 0002070734 · Chief Operating Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 240,000

Underlying: Class A Common Stock · 240,000 shares

Expires 2030-06-02

F1 · derivative.exercise_date: Stock options vest on June 2, 2026, subject to continued employment.

SEC source: 0001845437-25-000020 · wk-form4_1744402356.xml · nonDerivative · entry 1

Kelliher Joseph T · CIK 0001464551 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,103

F1 · shares: The reporting person received shares of Class A common stock in lieu of cash as payment for his services as a director of NET Power Inc.

SEC source: 0001845437-25-000016 · wk-form4_1743818266.xml · nonDerivative · entry 2

PATEL AKASH S. · CIK 0001979780 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

F2 · shares: The Reporting Person was issued 7,359 net shares of Class A Common Stock upon the vesting of 11,151 restricted stock units on April 2, 2025. The sale of such shares was effected pursuant to a Rule 10b5-1 trading plan.

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $2.25 to $2.39, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above.

SEC source: 0001845437-25-000018 · wk-form4_1744025656.xml · nonDerivative · entry 2

Rosser Kelly · CIK 0001608295 · Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,531

F2 · shares: Represents shares of Class A Common Stock sold to cover tax obligations related to the vesting of 3,658 restricted stock units on April 2, 2025.

SEC source: 0001845437-25-000016 · wk-form4_1743818266.xml · derivative · entry 3

PATEL AKASH S. · CIK 0001979780 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 151,208

Underlying: Class A Common Stock · 117,757 shares

Expires not disclosed

F4 · derivative.exercise_price: The Reporting Person will receive a number of shares of Class A common stock equal to 50% of the number of PSUs upon attainment of a 10% compound annual growth rate ("CAGR") of the 30-day volume weighted average price ("VWAP") of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025. The Reporting Person will receive a number of shares of Class A common stock equal to 100% of the number of PSUs upon attainment of a 12% CAGR of the VWAP of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025. The Reporting Person will receive a number of shares of Class A common stock equal to 200% of the number of PSUs upon attainment of a 15% CAGR of the VWAP of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025.

F4 · derivative.exercise_date: The Reporting Person will receive a number of shares of Class A common stock equal to 50% of the number of PSUs upon attainment of a 10% compound annual growth rate ("CAGR") of the 30-day volume weighted average price ("VWAP") of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025. The Reporting Person will receive a number of shares of Class A common stock equal to 100% of the number of PSUs upon attainment of a 12% CAGR of the VWAP of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025. The Reporting Person will receive a number of shares of Class A common stock equal to 200% of the number of PSUs upon attainment of a 15% CAGR of the VWAP of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025.

F4 · derivative.expiration_date: The Reporting Person will receive a number of shares of Class A common stock equal to 50% of the number of PSUs upon attainment of a 10% compound annual growth rate ("CAGR") of the 30-day volume weighted average price ("VWAP") of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025. The Reporting Person will receive a number of shares of Class A common stock equal to 100% of the number of PSUs upon attainment of a 12% CAGR of the VWAP of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025. The Reporting Person will receive a number of shares of Class A common stock equal to 200% of the number of PSUs upon attainment of a 15% CAGR of the VWAP of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025.

SEC source: 0001845437-25-000016 · wk-form4_1743818266.xml · nonDerivative · entry 1

PATEL AKASH S. · CIK 0001979780 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 457,790

F1 · shares: Restricted stock units that vest in three equal installments on each anniversary of April 2, 2025, subject to continued employment.

SEC source: 0001845437-25-000014 · wk-form4_1743818144.xml · derivative · entry 2

ALLEN BRIAN F. · CIK 0001975816 · COO and President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 170,009

Underlying: Class A Common Stock · 132,399 shares

Expires not disclosed

F2 · derivative.exercise_price: The Reporting Person will receive a number of shares of Class A common stock equal to 50% of the number of PSUs upon attainment of a 10% compound annual growth rate ("CAGR") of the 30-day volume weighted average price ("VWAP") of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025. The Reporting Person will receive a number of shares of Class A common stock equal to 100% of the number of PSUs upon attainment of a 12% CAGR of the VWAP of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025. The Reporting Person will receive a number of shares of Class A common stock equal to 200% of the number of PSUs upon attainment of a 15% CAGR of the VWAP of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025.

F2 · derivative.exercise_date: The Reporting Person will receive a number of shares of Class A common stock equal to 50% of the number of PSUs upon attainment of a 10% compound annual growth rate ("CAGR") of the 30-day volume weighted average price ("VWAP") of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025. The Reporting Person will receive a number of shares of Class A common stock equal to 100% of the number of PSUs upon attainment of a 12% CAGR of the VWAP of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025. The Reporting Person will receive a number of shares of Class A common stock equal to 200% of the number of PSUs upon attainment of a 15% CAGR of the VWAP of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025.

F2 · derivative.expiration_date: The Reporting Person will receive a number of shares of Class A common stock equal to 50% of the number of PSUs upon attainment of a 10% compound annual growth rate ("CAGR") of the 30-day volume weighted average price ("VWAP") of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025. The Reporting Person will receive a number of shares of Class A common stock equal to 100% of the number of PSUs upon attainment of a 12% CAGR of the VWAP of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025. The Reporting Person will receive a number of shares of Class A common stock equal to 200% of the number of PSUs upon attainment of a 15% CAGR of the VWAP of a share of Class A common stock on April 2, 2028 as compared to the VWAP of a share of Class A common stock on April 2, 2025.

SEC source: 0001845437-25-000014 · wk-form4_1743818144.xml · nonDerivative · entry 1

ALLEN BRIAN F. · CIK 0001975816 · COO and President

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 568,939

F1 · shares: Restricted stock units that vest in three equal installments on each anniversary of April 2, 2025, subject to continued employment.

SEC source: 0001845437-25-000018 · wk-form4_1744025656.xml · nonDerivative · entry 1

Rosser Kelly · CIK 0001608295 · Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 71,567

F1 · shares: Restricted stock units that vest in three equal installments on each anniversary of April 2, 2025, subject to continued employment.

SEC source: 0001845437-25-000003 · wk-form4_1736197467.xml · nonDerivative · entry 1

Kelliher Joseph T · CIK 0001464551 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,169

F1 · shares: The reporting person received shares of Class A common stock in lieu of cash as payment for his services as a director of NET Power Inc.

SEC source: 0001104659-24-123262 · tm2429528-3_4seq1.xml · nonDerivative · entry 1

NPEH, LLC · CIK 0001981772 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

F1 · price: The price reported reflects the weighted average sales price. The shares of Class A Common Stock were sold in multiple trades at prices ranging from $12.50 to $13.46. NPEH, LLC will provide upon request to the SEC, the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

SEC source: 0001104659-24-123261 · tm2429528-2_4seq1.xml · nonDerivative · entry 1

8 Rivers Capital, LLC · CIK 0001981100 · 10% owner

SK INC. · CIK 0001947998 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · By: NPEH, LLC

Disclosed balance after: 0

F1 · price: The price reported reflects the weighted average sales price. The shares of Class A Common Stock were sold in multiple trades at prices ranging from $12.50 to $13.46. NPEH, LLC ("NPEH") will provide upon request to the SEC, the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

F2 · ownership.nature: As manager and holder of approximately 91.4% of the outstanding equity in NPEH, 8 Rivers Capital, LLC ("8 Rivers") may be deemed to be a beneficial owner of the securities directly owned by NPEH. 8 Rivers disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that 8 Rivers is the beneficial owner of such securities for purposes of Section 16 or otherwise.

F3 · ownership.nature: SK Inc. ("SK") directly beneficially owns 100.0% of each of Tillandsia, Inc. ("Tillandsia"), Areca, Inc. ("Areca") and Chamaedorea, Inc. ("Chamaedorea"). Each of Tillandsia, Areca and Chamaedorea beneficially owns approximately 18.06%, 25.02% and 23.41%, respectively, of the voting units of 8 Rivers and thus SK may be deemed to be a beneficial owner of the securities beneficially owned by 8 Rivers and NPEH. SK disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that SK is the beneficial owner of such securities for purposes of Section 16 or otherwise.

SEC source: 0001845437-24-000066 · wk-form4_1732654844.xml · derivative · entry 4

PATEL AKASH S. · CIK 0001979780 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 640,448

Underlying: Class A Common Stock · 150,000 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: On November 22, 2024, 150,000 Class A Units of NET Power Operations LLC (a subsidiary of the issuer) held by the reporting person were redeemed in exchange for an equal number of shares of the issuer's Class A Common Stock pursuant to a redemption notice from the reporting person dated November 22, 2024, and upon such redemption, 150,000 shares of the issuer's Class B Common Stock held by the reporting person were surrendered to the issuer and canceled.

F1 · derivative.exercise_date: On November 22, 2024, 150,000 Class A Units of NET Power Operations LLC (a subsidiary of the issuer) held by the reporting person were redeemed in exchange for an equal number of shares of the issuer's Class A Common Stock pursuant to a redemption notice from the reporting person dated November 22, 2024, and upon such redemption, 150,000 shares of the issuer's Class B Common Stock held by the reporting person were surrendered to the issuer and canceled.

F1 · derivative.expiration_date: On November 22, 2024, 150,000 Class A Units of NET Power Operations LLC (a subsidiary of the issuer) held by the reporting person were redeemed in exchange for an equal number of shares of the issuer's Class A Common Stock pursuant to a redemption notice from the reporting person dated November 22, 2024, and upon such redemption, 150,000 shares of the issuer's Class B Common Stock held by the reporting person were surrendered to the issuer and canceled.

SEC source: 0001845437-24-000066 · wk-form4_1732654844.xml · nonDerivative · entry 3

PATEL AKASH S. · CIK 0001979780 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 0

F2 · kind: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan.

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions ranging from $12.35 to $13.41, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above.

SEC source: 0001845437-24-000066 · wk-form4_1732654844.xml · nonDerivative · entry 2

PATEL AKASH S. · CIK 0001979780 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 150,000

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: On November 22, 2024, 150,000 Class A Units of NET Power Operations LLC (a subsidiary of the issuer) held by the reporting person were redeemed in exchange for an equal number of shares of the issuer's Class A Common Stock pursuant to a redemption notice from the reporting person dated November 22, 2024, and upon such redemption, 150,000 shares of the issuer's Class B Common Stock held by the reporting person were surrendered to the issuer and canceled.

SEC source: 0001845437-24-000066 · wk-form4_1732654844.xml · nonDerivative · entry 1

PATEL AKASH S. · CIK 0001979780 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 640,448

F1 · kind: On November 22, 2024, 150,000 Class A Units of NET Power Operations LLC (a subsidiary of the issuer) held by the reporting person were redeemed in exchange for an equal number of shares of the issuer's Class A Common Stock pursuant to a redemption notice from the reporting person dated November 22, 2024, and upon such redemption, 150,000 shares of the issuer's Class B Common Stock held by the reporting person were surrendered to the issuer and canceled.

SEC source: 0001104659-24-121693 · tm2429117-2_4seq1.xml · nonDerivative · entry 4

8 Rivers Capital, LLC · CIK 0001981100 · 10% owner

SK INC. · CIK 0001947998 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · By: NPEH, LLC

Disclosed balance after: 431,009

F4 · price: The price reported reflects the weighted average sales price. The shares of Class A Common Stock were sold in multiple trades at prices ranging from $12.55 to $13.04. NPEH will provide upon request to the SEC, the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

F5 · ownership.nature: As manager and holder of approximately 91.4% of the outstanding equity in NPEH, 8 Rivers Capital, LLC ("8 Rivers") may be deemed to be a beneficial owner of the securities directly owned by NPEH. 8 Rivers disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that 8 Rivers is the beneficial owner of such securities for purposes of Section 16 or otherwise.

F6 · ownership.nature: SK Inc. ("SK") directly beneficially owns 100.0% of each of Tillandsia, Inc. ("Tillandsia"), Areca, Inc. ("Areca") and Chamaedorea, Inc. ("Chamaedorea"). Each of Tillandsia, Areca and Chamaedorea beneficially owns approximately 18.06%, 25.02% and 23.41%, respectively, of the voting units of 8 Rivers and thus SK may be deemed to be a beneficial owner of the securities beneficially owned by 8 Rivers and NPEH. SK disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that SK is the beneficial owner of such securities for purposes of Section 16 or otherwise.

SEC source: 0001104659-24-121689 · tm2429117-1_4seq1.xml · nonDerivative · entry 4

NPEH, LLC · CIK 0001981772 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 431,009

F4 · price: The price reported reflects the weighted average sales price. The shares of Class A Common Stock were sold in multiple trades at prices ranging from $12.55 to $13.04. NPEH will provide upon request to the SEC, the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

SEC source: 0001104659-24-121693 · tm2429117-2_4seq1.xml · nonDerivative · entry 3

8 Rivers Capital, LLC · CIK 0001981100 · 10% owner

SK INC. · CIK 0001947998 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · By: NPEH, LLC

Disclosed balance after: 940,049

F3 · price: The price reported reflects the weighted average sales price. The shares of Class A Common Stock were sold in multiple trades at prices ranging from $12.315 to $12.93. NPEH will provide upon request to the SEC, the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

F5 · ownership.nature: As manager and holder of approximately 91.4% of the outstanding equity in NPEH, 8 Rivers Capital, LLC ("8 Rivers") may be deemed to be a beneficial owner of the securities directly owned by NPEH. 8 Rivers disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that 8 Rivers is the beneficial owner of such securities for purposes of Section 16 or otherwise.

F6 · ownership.nature: SK Inc. ("SK") directly beneficially owns 100.0% of each of Tillandsia, Inc. ("Tillandsia"), Areca, Inc. ("Areca") and Chamaedorea, Inc. ("Chamaedorea"). Each of Tillandsia, Areca and Chamaedorea beneficially owns approximately 18.06%, 25.02% and 23.41%, respectively, of the voting units of 8 Rivers and thus SK may be deemed to be a beneficial owner of the securities beneficially owned by 8 Rivers and NPEH. SK disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that SK is the beneficial owner of such securities for purposes of Section 16 or otherwise.

SEC source: 0001104659-24-121689 · tm2429117-1_4seq1.xml · nonDerivative · entry 3

NPEH, LLC · CIK 0001981772 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 940,049

F3 · price: The price reported reflects the weighted average sales price. The shares of Class A Common Stock were sold in multiple trades at prices ranging from $12.315 to $12.93. NPEH will provide upon request to the SEC, the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

SEC source: 0001104659-24-121693 · tm2429117-2_4seq1.xml · derivative · entry 5

8 Rivers Capital, LLC · CIK 0001981100 · 10% owner

SK INC. · CIK 0001947998 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · By: NPEH, LLC

Disclosed balance after: 26,729,880

Underlying: Class A Common Stock · 1,260,420 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The Class A Units of NET Power Operations LLC are exchangeable into shares of the Issuer's Class A Common Stock or, at the Issuer's election, cash, on a one-for-one basis and have no expiration date. On November 19, 2024, NPEH, LLC ("NPEH") exchanged 1,260,420 Class A Units of NET Power Operations LLC for 1,260,420 shares of the Issuer's Class A Common Stock.

F1 · price: The Class A Units of NET Power Operations LLC are exchangeable into shares of the Issuer's Class A Common Stock or, at the Issuer's election, cash, on a one-for-one basis and have no expiration date. On November 19, 2024, NPEH, LLC ("NPEH") exchanged 1,260,420 Class A Units of NET Power Operations LLC for 1,260,420 shares of the Issuer's Class A Common Stock.

F1 · derivative.exercise_date: The Class A Units of NET Power Operations LLC are exchangeable into shares of the Issuer's Class A Common Stock or, at the Issuer's election, cash, on a one-for-one basis and have no expiration date. On November 19, 2024, NPEH, LLC ("NPEH") exchanged 1,260,420 Class A Units of NET Power Operations LLC for 1,260,420 shares of the Issuer's Class A Common Stock.

F1 · derivative.expiration_date: The Class A Units of NET Power Operations LLC are exchangeable into shares of the Issuer's Class A Common Stock or, at the Issuer's election, cash, on a one-for-one basis and have no expiration date. On November 19, 2024, NPEH, LLC ("NPEH") exchanged 1,260,420 Class A Units of NET Power Operations LLC for 1,260,420 shares of the Issuer's Class A Common Stock.

F5 · ownership.nature: As manager and holder of approximately 91.4% of the outstanding equity in NPEH, 8 Rivers Capital, LLC ("8 Rivers") may be deemed to be a beneficial owner of the securities directly owned by NPEH. 8 Rivers disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that 8 Rivers is the beneficial owner of such securities for purposes of Section 16 or otherwise.

F6 · ownership.nature: SK Inc. ("SK") directly beneficially owns 100.0% of each of Tillandsia, Inc. ("Tillandsia"), Areca, Inc. ("Areca") and Chamaedorea, Inc. ("Chamaedorea"). Each of Tillandsia, Areca and Chamaedorea beneficially owns approximately 18.06%, 25.02% and 23.41%, respectively, of the voting units of 8 Rivers and thus SK may be deemed to be a beneficial owner of the securities beneficially owned by 8 Rivers and NPEH. SK disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that SK is the beneficial owner of such securities for purposes of Section 16 or otherwise.

SEC source: 0001104659-24-121693 · tm2429117-2_4seq1.xml · nonDerivative · entry 2

8 Rivers Capital, LLC · CIK 0001981100 · 10% owner

SK INC. · CIK 0001947998 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · By: NPEH, LLC

Disclosed balance after: 26,729,880

F2 · price: For each Class A Unit of Net Power Operations LLC, NPEH owns a corresponding share of Class B Common Stock of the Issuer. Upon the exchange of 1,260,420 Class A Units of Net Power Operations LLC, an equal number of shares of Class B Common Stock of the Issuer held by NPEH, which have no economic value, were cancelled.

F5 · ownership.nature: As manager and holder of approximately 91.4% of the outstanding equity in NPEH, 8 Rivers Capital, LLC ("8 Rivers") may be deemed to be a beneficial owner of the securities directly owned by NPEH. 8 Rivers disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that 8 Rivers is the beneficial owner of such securities for purposes of Section 16 or otherwise.

F6 · ownership.nature: SK Inc. ("SK") directly beneficially owns 100.0% of each of Tillandsia, Inc. ("Tillandsia"), Areca, Inc. ("Areca") and Chamaedorea, Inc. ("Chamaedorea"). Each of Tillandsia, Areca and Chamaedorea beneficially owns approximately 18.06%, 25.02% and 23.41%, respectively, of the voting units of 8 Rivers and thus SK may be deemed to be a beneficial owner of the securities beneficially owned by 8 Rivers and NPEH. SK disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that SK is the beneficial owner of such securities for purposes of Section 16 or otherwise.

SEC source: 0001104659-24-121693 · tm2429117-2_4seq1.xml · nonDerivative · entry 1

8 Rivers Capital, LLC · CIK 0001981100 · 10% owner

SK INC. · CIK 0001947998 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · By: NPEH, LLC

Disclosed balance after: 1,260,420

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The Class A Units of NET Power Operations LLC are exchangeable into shares of the Issuer's Class A Common Stock or, at the Issuer's election, cash, on a one-for-one basis and have no expiration date. On November 19, 2024, NPEH, LLC ("NPEH") exchanged 1,260,420 Class A Units of NET Power Operations LLC for 1,260,420 shares of the Issuer's Class A Common Stock.

F5 · ownership.nature: As manager and holder of approximately 91.4% of the outstanding equity in NPEH, 8 Rivers Capital, LLC ("8 Rivers") may be deemed to be a beneficial owner of the securities directly owned by NPEH. 8 Rivers disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that 8 Rivers is the beneficial owner of such securities for purposes of Section 16 or otherwise.

F6 · ownership.nature: SK Inc. ("SK") directly beneficially owns 100.0% of each of Tillandsia, Inc. ("Tillandsia"), Areca, Inc. ("Areca") and Chamaedorea, Inc. ("Chamaedorea"). Each of Tillandsia, Areca and Chamaedorea beneficially owns approximately 18.06%, 25.02% and 23.41%, respectively, of the voting units of 8 Rivers and thus SK may be deemed to be a beneficial owner of the securities beneficially owned by 8 Rivers and NPEH. SK disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that SK is the beneficial owner of such securities for purposes of Section 16 or otherwise.

SEC source: 0001104659-24-121689 · tm2429117-1_4seq1.xml · derivative · entry 5

NPEH, LLC · CIK 0001981772 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 26,729,880

Underlying: Class A Common Stock · 1,260,420 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: The Class A Units of NET Power Operations LLC are exchangeable into shares of the Issuer's Class A Common Stock or, at the Issuer's election, cash, on a one-for-one basis and have no expiration date. On November 19, 2024, NPEH, LLC ("NPEH") exchanged 1,260,420 Class A Units of NET Power Operations LLC for 1,260,420 shares of the Issuer's Class A Common Stock.

F1 · price: The Class A Units of NET Power Operations LLC are exchangeable into shares of the Issuer's Class A Common Stock or, at the Issuer's election, cash, on a one-for-one basis and have no expiration date. On November 19, 2024, NPEH, LLC ("NPEH") exchanged 1,260,420 Class A Units of NET Power Operations LLC for 1,260,420 shares of the Issuer's Class A Common Stock.

F1 · derivative.exercise_date: The Class A Units of NET Power Operations LLC are exchangeable into shares of the Issuer's Class A Common Stock or, at the Issuer's election, cash, on a one-for-one basis and have no expiration date. On November 19, 2024, NPEH, LLC ("NPEH") exchanged 1,260,420 Class A Units of NET Power Operations LLC for 1,260,420 shares of the Issuer's Class A Common Stock.

F1 · derivative.expiration_date: The Class A Units of NET Power Operations LLC are exchangeable into shares of the Issuer's Class A Common Stock or, at the Issuer's election, cash, on a one-for-one basis and have no expiration date. On November 19, 2024, NPEH, LLC ("NPEH") exchanged 1,260,420 Class A Units of NET Power Operations LLC for 1,260,420 shares of the Issuer's Class A Common Stock.

SEC source: 0001104659-24-121689 · tm2429117-1_4seq1.xml · nonDerivative · entry 2

NPEH, LLC · CIK 0001981772 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 26,729,880

F2 · price: For each Class A Unit of Net Power Operations LLC, NPEH owns a corresponding share of Class B Common Stock of the Issuer. Upon the exchange of 1,260,420 Class A Units of Net Power Operations LLC, an equal number of shares of Class B Common Stock of the Issuer held by NPEH, which have no economic value, were cancelled.

SEC source: 0001104659-24-121689 · tm2429117-1_4seq1.xml · nonDerivative · entry 1

NPEH, LLC · CIK 0001981772 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,260,420

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The Class A Units of NET Power Operations LLC are exchangeable into shares of the Issuer's Class A Common Stock or, at the Issuer's election, cash, on a one-for-one basis and have no expiration date. On November 19, 2024, NPEH, LLC ("NPEH") exchanged 1,260,420 Class A Units of NET Power Operations LLC for 1,260,420 shares of the Issuer's Class A Common Stock.

SEC source: 0001104659-24-109960 · tm2426503-2_4seq1.xml · nonDerivative · entry 2

NPEH, LLC · CIK 0001981772 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

F2 · price: The price reported reflects the weighted average sales price. The shares of Class A Common Stock were sold in multiple trades at prices ranging from $7.10 to $7.555. The Reporting Person will provide upon request to the SEC, the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

SEC source: 0001104659-24-109959 · tm2426503-1_4seq1.xml · nonDerivative · entry 2

8 Rivers Capital, LLC · CIK 0001981100 · 10% owner

SK INC. · CIK 0001947998 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · By: NPEH, LLC

Disclosed balance after: 0

F2 · price: The price reported reflects the weighted average sales price. The shares of Class A Common Stock were sold in multiple trades at prices ranging from $7.10 to $7.555. NPEH will provide upon request to the SEC, the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

F3 · ownership.nature: As manager and holder of approximately 91.4% of the outstanding equity in NPEH, 8 Rivers Capital, LLC ("8 Rivers") may be deemed to be a beneficial owner of the securities directly owned by NPEH. 8 Rivers disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that 8 Rivers is the beneficial owner of such securities for purposes of Section 16 or otherwise.

F4 · ownership.nature: SK Inc. ("SK") indirectly beneficially owns 100.0% of each of Tillandsia, Inc. ("Tillandsia"), Areca, Inc. ("Areca") and Chamaedorea, Inc. ("Chamaedorea"). Each of Tillandsia, Areca and Chamaedorea beneficially owns approximately 18.06%, 25.02% and 23.41%, respectively, of the voting units of 8 Rivers and thus SK may be deemed to be a beneficial owner of the securities beneficially owned by 8 Rivers and NPEH. SK disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that SK is the beneficial owner of such securities for purposes of Section 16 or otherwise.

SEC source: 0001104659-24-109960 · tm2426503-2_4seq1.xml · nonDerivative · entry 1

NPEH, LLC · CIK 0001981772 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 199,369

F1 · price: The price reported reflects the weighted average sales price. The shares of Class A Common Stock were sold in multiple trades at prices ranging from $7.00 to $7.175. The Reporting Person will provide upon request to the SEC, the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.