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Mary Beth Mandanas

Director at Energy Vault Holdings
Board

About Mary Beth Mandanas

Independent director since 2022, age 59, currently CEO of Onyx Renewable Partners L.P. (since January 2022), with prior finance, strategy, and risk management leadership across renewables. Education: MBA, Vanderbilt University; BS, University of South Carolina (magna cum laude). The Board has affirmatively determined she is independent under NYSE rules .

Past Roles

OrganizationRoleTenureCommittees/Impact
CleanChoice Energy, Inc.EVP, Chief Strategy OfficerFall 2015–May 2020 Led strategic planning; capital raising; investor/ banking relations; risk management protocols
Sol Systems, LLCChief Investment Officer (consultant)Aug 2020–Aug 2021 Renewable infrastructure and impact investing
TortoiseEcofin Acquisition Corp III (TRTL)Independent Director; Audit ChairJul 2021–Jul 2023 Audit Chair

External Roles

OrganizationRoleTenureCommittees
Onyx Renewable Partners L.P.Chief Executive OfficerJan 2022–present N/A

Board Governance

  • Committee assignments: Audit Committee member (financial expert); Nominating & Corporate Governance Committee Chair; Compensation Committee not listed .
  • Independence: Determined independent by Board; all committee members are independent .
  • Attendance & engagement: Board met 4 times in 2024; each director attended at least 75% of Board and committee meetings; all seven directors attended the 2024 Annual Meeting .
  • Board classification & term: Class I nominee for re-election at the May 30, 2025 meeting to serve until the 2028 annual meeting .
CommitteeRoleIndependenceMeetings in 2024Attendance
AuditMember; qualifies as “audit committee financial expert”Yes 4 ≥75% (Board standard achieved by each director)
Nominating & Corporate GovernanceChairYes 1 ≥75%

Fixed Compensation

  • 2024 director compensation: Cash fees $75,000; stock awards (grant date fair value) $174,706; total $249,706. Mix skewed to equity, supporting alignment .
ComponentAmount ($)
Fees Earned or Paid in Cash75,000
Stock Awards (grant-date fair value)174,706
Total249,706
  • Director compensation program (policy):
    • Annual cash retainer: $75,000
    • Initial RSU grant: ~$200,000 at appointment; +$15,000 RSU if committee chair
    • Annual RSU grant: ~$100,000 if ≥6 months of service; +$15,000 RSU if committee chair
    • Vesting: Initial RSUs vest in three annual installments; Annual RSUs vest by next annual meeting; change-in-control fully vests director RSUs .
ElementTerms
Annual cash retainer$75,000
Initial RSU~$200,000; +$15,000 if chair
Annual RSU~$100,000; +$15,000 if chair
VestingInitial: 3 annual tranches; Annual: full by next annual meeting
Change-in-controlFull vesting of Initial and Annual RSUs

Performance Compensation

  • No performance-conditioned director equity metrics disclosed; director awards are time-based RSUs per program (with change-in-control vesting) .
Performance MetricApplication to Director Pay
Performance conditionsNone disclosed for non-executive directors (time-based RSUs)

Other Directorships & Interlocks

CompanyRoleDatesCommittee/Notes
TortoiseEcofin Acquisition Corp III (TRTL; NYSE: TRTL)Independent Director; Audit ChairJul 2021–Jul 2023 Audit Chair
  • No current public-company directorships disclosed beyond NRGV; no shared directorships indicating interlocks with NRGV competitors/suppliers were disclosed .

Expertise & Qualifications

  • Finance, risk management, investment banking, renewables industry expertise; qualifies as audit committee financial expert .
  • Education: MBA (Vanderbilt); BS (University of South Carolina, magna cum laude) .

Equity Ownership

  • Beneficial ownership: 94,840 shares; less than 1% of outstanding; includes 79,337 RSUs vesting within 60 days of March 31, 2025 .
  • Total stock awards outstanding (director holdings table): 159,203 RSUs .
  • Insider Trading Policy prohibits hedging and pledging without approval, reducing alignment risks; no pledges disclosed for directors .
CategoryShares% of OutstandingNotes
Beneficial ownership (as of Mar 31, 2025)94,840 <1% Includes 79,337 RSUs vesting within 60 days
Total stock awards outstanding159,203 N/ANon-employee director RSUs outstanding

Governance Assessment

  • Positive signals:

    • Independence affirmed; chairs Nominating & Corporate Governance; member of Audit with “financial expert” status .
    • Strong attendance standard met across Board/committees; directors attended 2024 Annual Meeting .
    • Director pay structure favors equity (2024 equity $174,706 vs cash $75,000), supporting alignment with shareholders; RSU vesting aligned with service continuity .
  • Monitoring items:

    • Ownership remains modest in % terms (<1%); continued accumulation and long-term holding would further strengthen alignment .
    • As Onyx Renewable Partners’ CEO, monitor for any future related-party dealings; none disclosed involving Mandanas to date .
  • Conflicts/related-party exposure:

    • Company disclosed no related-party transactions exceeding $120,000 involving directors/officers other than items described (a 2023 patent option with an affiliate of a different director); no transactions involving Mandanas disclosed .
    • Insider Trading Policy prohibits hedging/pledging without approval, mitigating misalignment risks .
  • RED FLAGS: None identified specific to Mandanas (no related-party dealings, hedging/pledging restrictions in place, independent committee leadership) .