EROC · ERock, Inc.

Consists of 13,024 restricted stock units granted to the Reporting Person, which will vest on the earlier of the first anniversary of the grant date or the Issuer's next annual meeting of stockholders, subject to the Reporting Person's continued service to the Issuer. Each restricted stock unit represents the right to receive one share of Class A common stock of the Issuer following vesting.

The Class B Units are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A Common Stock of the Issuer or cash (at the Issuer's election). Upon exchange of a Class B Unit, the corresponding share of Class B Common Stock will be automatically cancelled.

Represents Class B Units of Enchanted Rock Holdings, LLC sold by the Reporting Person to the Issuer in connection with the closing of the Issuer's initial public offering ("IPO") at a price per Class B Unit of $19.85 (the per-share price paid by the underwriters for shares of the Class A Common Stock in the IPO, less the Reporting Person's share of offering expenses). In connection with such sale, the Issuer automatically cancelled an equivalent number of shares of Class B Common Stock held by the Reporting Person.

The Class B Units are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A Common Stock of the Issuer or cash (at the Issuer's election). Upon exchange of a Class B Unit, the corresponding share of Class B Common Stock will be automatically cancelled.

Represents Class B Units of Enchanted Rock Holdings, LLC sold by the Reporting Person to the Issuer in connection with the closing of the Issuer's initial public offering ("IPO") at a price per Class B Unit of $19.85 (the per-share price paid by the underwriters for shares of the Class A Common Stock in the IPO, less the Reporting Person's share of offering expenses). In connection with such sale, the Issuer automatically cancelled an equivalent number of shares of Class B Common Stock held by the Reporting Person.

The Class B Units are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A Common Stock.

The Issuer used approximately $119.9 million of the net proceeds from the closing of the Offering to purchase 6,041,206 Class B Units from Flagship. An equal number of shares of the Issuer's Class B common stock were cancelled in connection with the repurchase of the Class B Units.

These securities are directly held by EIP Flagship Fund I ER Holdings LLC ("Flagship").

Each of EIF ER Holdings LLC ("EIF ER Holdings", as the sole owner of Flagship), Energy Impact Fund (FT-D) LP ("FT-D", as owner of EIF ER Holdings), Energy Impact Partners LLC ("EIP LLC", as the managing member of EIF ER Holdings and the general partner of FT-D) and Hans Kobler, a nominee to the Issuer's Board of Directors ("Board") (as the managing member of EIP LLC), may also be deemed to be the beneficial owners having shared voting power and shared investment power of the securities held by Flagship. Each of FT-B, EIP LLC (as the general partner of FT-B) and Mr. Kobler (as the managing member of EIP LLC) may also be deemed to be the beneficial owners having shared voting power and shared investment power of the securities held by FT-B. Voting and investment decisions with respect to the securities described in this Form 4 are made by the investment committee of EIP LLC, which is comprised of seven individuals,

(Continued from footnote 4) including Mr. Kobler, Lindsay Luger and Sameer Reddy, each of whom is a nominee to the Issuer's Board. Each member of this investment committee disclaims beneficial ownership of all securities described by this Form 4 except to the extent of his or her pecuniary interest therein.

The Class B Units are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A Common Stock.

The Issuer used approximately $119.9 million of the net proceeds from the closing of the Offering to purchase 6,041,206 Class B Units from Flagship. An equal number of shares of the Issuer's Class B common stock were cancelled in connection with the repurchase of the Class B Units.

These securities are directly held by EIP Flagship Fund I ER Holdings LLC ("Flagship").

Each of EIF ER Holdings LLC ("EIF ER Holdings", as the sole owner of Flagship), Energy Impact Fund (FT-D) LP ("FT-D", as owner of EIF ER Holdings), Energy Impact Partners LLC ("EIP LLC", as the managing member of EIF ER Holdings and the general partner of FT-D) and the Reporting Person, a nominee to the Issuer's Board of Directors ("Board") (as the managing member of EIP LLC), may also be deemed to be the beneficial owners having shared voting power and shared investment power of the securities held by Flagship. Each of FT-B, EIP LLC (as the general partner of FT-B) and the Reporting Person (as the managing member of EIP LLC) may also be deemed to be the beneficial owners having shared voting power and shared investment power of the securities held by FT-B. Voting and investment decisions with respect to the securities described in this Form 4 are made by the investment committee of EIP LLC, which is comprised of seven individuals, including the Reporting Person,

(Continued from footnote 4) Lindsay Luger and Sameer Reddy, each of whom is a nominee to the Issuer's Board. Each member of this investment committee disclaims beneficial ownership of all securities described by Form 4 except to the extent of his or her pecuniary interest therein.

Represents Class B Units of Enchanted Rock Holdings, LLC sold by the Reporting Person to the Issuer in connection with the closing of the Issuer's initial public offering ("IPO") at a price per Class B Unit of $19.85 (the per-share price paid by the underwriters for shares of the Class A Common Stock in the IPO, less the Reporting Person's share of offering expenses). In connection with such sale, the Issuer automatically cancelled an equivalent number of shares of Class B Common Stock held by the Reporting Person.

Consists of 13,024 restricted stock units granted to the Reporting Person, which will vest on the earlier of the first anniversary of the grant date or the Issuer's next annual meeting of stockholders, subject to the Reporting Person's continued service to the Issuer. Each restricted stock unit represents the right to receive one share of Class A common stock of the Issuer following vesting.

Consists of 13,024 restricted stock units granted to the Reporting Person, which will vest on the earlier of the first anniversary of the grant date or the Issuer's next annual meeting of stockholders, subject to the Reporting Person's continued service to the Issuer. Each restricted stock unit represents the right to receive one share of Class A common stock of the Issuer following vesting.

The Issuer used approximately $119.9 million of the net proceeds from the closing of the Offering to purchase 6,041,206 Class B Units from Flagship. An equal number of shares of the Issuer's Class B common stock were cancelled in connection with the repurchase of the Class B Units.

Shares of the Issuer's Class B common stock ("Class B Common Stock") have no economic value and have one vote per share. One share of Class B Common Stock is issued for each Class B Unit ("Class B Units") of Enchanted Rock Holdings, LLC ("ER Holdings") held. Upon an exchange of Class B Units for shares of the Issuer's Class A common stock ("Class A Common Stock"), an equivalent number of shares of Class B Common Stock held by such holder will be automatically cancelled.

These securities are directly held by EIP Flagship Fund I ER Holdings LLC ("Flagship").

Each of EIF ER Holdings LLC ("EIF ER Holdings", as the sole owner of Flagship), Energy Impact Fund (FT-D) LP ("FT-D", as owner of EIF ER Holdings), Energy Impact Partners LLC ("EIP LLC", as the managing member of EIF ER Holdings and the general partner of FT-D) and Hans Kobler, a nominee to the Issuer's Board of Directors ("Board") (as the managing member of EIP LLC), may also be deemed to be the beneficial owners having shared voting power and shared investment power of the securities held by Flagship. Each of FT-B, EIP LLC (as the general partner of FT-B) and Mr. Kobler (as the managing member of EIP LLC) may also be deemed to be the beneficial owners having shared voting power and shared investment power of the securities held by FT-B. Voting and investment decisions with respect to the securities described in this Form 4 are made by the investment committee of EIP LLC, which is comprised of seven individuals,

(Continued from footnote 4) including Mr. Kobler, Lindsay Luger and Sameer Reddy, each of whom is a nominee to the Issuer's Board. Each member of this investment committee disclaims beneficial ownership of all securities described by this Form 4 except to the extent of his or her pecuniary interest therein.

Consists of 13,024 restricted stock units granted to the Reporting Person, which will vest on the earlier of the first anniversary of the grant date or the Issuer's next annual meeting of stockholders, subject to the Reporting Person's continued service to the Issuer. Each restricted stock unit represents the right to receive one share of Class A common stock of the Issuer following vesting.

In connection with the Issuer's initial public offering of Class A common stock (the "Offering"), EIF ER Blocker LLC ("EIF ER Blocker") merged with and into the Issuer pursuant to the Blocker Mergers (as defined in the Issuer's prospectus filed with Securities and Exchange Commission on June 10, 2026 (the "Prospectus")). As a result of the merger, 20,751,551 Class A Units held by EIF ER Blocker were cancelled, and, as consideration pursuant to the Blocker Mergers, FT-B received 19,350,897 shares of Class A common stock of the Issuer and approximately $27.8 million in cash from the net proceeds from the closing of the Offering.

These securities are directly held by Energy Impact Fund (FT-B) LP ("FT-B").

Each of EIF ER Holdings LLC ("EIF ER Holdings", as the sole owner of Flagship), Energy Impact Fund (FT-D) LP ("FT-D", as owner of EIF ER Holdings), Energy Impact Partners LLC ("EIP LLC", as the managing member of EIF ER Holdings and the general partner of FT-D) and Hans Kobler, a nominee to the Issuer's Board of Directors ("Board") (as the managing member of EIP LLC), may also be deemed to be the beneficial owners having shared voting power and shared investment power of the securities held by Flagship. Each of FT-B, EIP LLC (as the general partner of FT-B) and Mr. Kobler (as the managing member of EIP LLC) may also be deemed to be the beneficial owners having shared voting power and shared investment power of the securities held by FT-B. Voting and investment decisions with respect to the securities described in this Form 4 are made by the investment committee of EIP LLC, which is comprised of seven individuals,

(Continued from footnote 4) including Mr. Kobler, Lindsay Luger and Sameer Reddy, each of whom is a nominee to the Issuer's Board. Each member of this investment committee disclaims beneficial ownership of all securities described by this Form 4 except to the extent of his or her pecuniary interest therein.

The Issuer used approximately $119.9 million of the net proceeds from the closing of the Offering to purchase 6,041,206 Class B Units from Flagship. An equal number of shares of the Issuer's Class B common stock were cancelled in connection with the repurchase of the Class B Units.

Shares of the Issuer's Class B common stock ("Class B Common Stock") have no economic value and have one vote per share. One share of Class B Common Stock is issued for each Class B Unit ("Class B Units") of Enchanted Rock Holdings, LLC ("ER Holdings") held. Upon an exchange of Class B Units for shares of the Issuer's Class A common stock ("Class A Common Stock"), an equivalent number of shares of Class B Common Stock held by such holder will be automatically cancelled.

These securities are directly held by EIP Flagship Fund I ER Holdings LLC ("Flagship").

Each of EIF ER Holdings LLC ("EIF ER Holdings", as the sole owner of Flagship), Energy Impact Fund (FT-D) LP ("FT-D", as owner of EIF ER Holdings), Energy Impact Partners LLC ("EIP LLC", as the managing member of EIF ER Holdings and the general partner of FT-D) and the Reporting Person, a nominee to the Issuer's Board of Directors ("Board") (as the managing member of EIP LLC), may also be deemed to be the beneficial owners having shared voting power and shared investment power of the securities held by Flagship. Each of FT-B, EIP LLC (as the general partner of FT-B) and the Reporting Person (as the managing member of EIP LLC) may also be deemed to be the beneficial owners having shared voting power and shared investment power of the securities held by FT-B. Voting and investment decisions with respect to the securities described in this Form 4 are made by the investment committee of EIP LLC, which is comprised of seven individuals, including the Reporting Person,

(Continued from footnote 4) Lindsay Luger and Sameer Reddy, each of whom is a nominee to the Issuer's Board. Each member of this investment committee disclaims beneficial ownership of all securities described by Form 4 except to the extent of his or her pecuniary interest therein.

In connection with the Issuer's initial public offering of Class A common stock (the "Offering"), EIF ER Blocker LLC ("EIF ER Blocker") merged with and into the Issuer pursuant to the Blocker Mergers (as defined in the Issuer's prospectus filed with Securities and Exchange Commission on June 10, 2026 (the "Prospectus")). As a result of the merger, 20,751,551 Class A Units held by EIF ER Blocker were cancelled, and as consideration pursuant to the Blocker Mergers, FT-B received 19,350,897 shares of Class A Common Stock and approximately $27.8 million in cash from the net proceeds from the closing of the Offering.

These securities are directly held by Energy Impact Fund (FT-B) LP ("FT-B").

Each of EIF ER Holdings LLC ("EIF ER Holdings", as the sole owner of Flagship), Energy Impact Fund (FT-D) LP ("FT-D", as owner of EIF ER Holdings), Energy Impact Partners LLC ("EIP LLC", as the managing member of EIF ER Holdings and the general partner of FT-D) and the Reporting Person, a nominee to the Issuer's Board of Directors ("Board") (as the managing member of EIP LLC), may also be deemed to be the beneficial owners having shared voting power and shared investment power of the securities held by Flagship. Each of FT-B, EIP LLC (as the general partner of FT-B) and the Reporting Person (as the managing member of EIP LLC) may also be deemed to be the beneficial owners having shared voting power and shared investment power of the securities held by FT-B. Voting and investment decisions with respect to the securities described in this Form 4 are made by the investment committee of EIP LLC, which is comprised of seven individuals, including the Reporting Person,

(Continued from footnote 4) Lindsay Luger and Sameer Reddy, each of whom is a nominee to the Issuer's Board. Each member of this investment committee disclaims beneficial ownership of all securities described by Form 4 except to the extent of his or her pecuniary interest therein.

Represents Class B Units of Enchanted Rock Holdings, LLC sold by the Reporting Person to the Issuer in connection with the closing of the Issuer's initial public offering ("IPO") at a price per Class B Unit of $19.85 (the per-share price paid by the underwriters for shares of the Class A Common Stock in the IPO, less the Reporting Person's share of offering expenses). In connection with such sale, the Issuer automatically cancelled an equivalent number of shares of Class B Common Stock held by the Reporting Person.