Mary Mandanas

Director/Board Member at ENERGY VAULT HOLDINGS, INC.

Net worth: 2 M $ as of 2026-06-29

60 year

91 connections

Finance

Consumer Services

Utilities

Profile

Mary Beth Mandanas is Co-Chief Executive Officer at Onyx Renewable Partners LP since 2022.
Ms. Mandanas is Independent Non-Executive Director at Energy Vault Holdings, Inc. since 2022.
Former roles include Managing Director at Citigroup, Inc., Managing Director at Utility Corp., Managing Director at IEG (Deutschland) GmbH from 2007 to 2013, Independent Director at TortoiseEcofin Acquisition Corp.
III from 2021 to 2023, Head-Corporate Banking at RBC Capital Markets LLC from 2013 to 2015, Vice President at Bank of America NA (Charlotte, North Carolina), Trustee at University of South Carolina Business Partnership Foundation, Chief Investment Officer at Sol Systems LLC in 2021, and Executive Vice President & Chief Strategy Officer at CleanChoice Energy, Inc. from 2015 to 2020.
Education includes an MBA from Vanderbilt University and an undergraduate degree from the University of South Carolina.

Known holdings in public companies

Company	Date	Number of shares	Valuation	Valuation date
ENERGY VAULT HOLDINGS, INC. 0.21%	2026-05-28	372,864 ( 0.21% )	2 M $	2026-06-29

Mary Mandanas active positions

Companies	Position	Start
ENERGY VAULT HOLDINGS, INC.	Director/Board Member	2022-02-23
Onyx Renewable Partners LP Onyx Renewable Partners LP Alternative Power GenerationUtilities Offers clean energy and decarbonization solutions	Chief Executive Officer	2021-12-31

All active positions of Mary Mandanas

Former positions of Mary Mandanas

Companies	Position	End
TORTOISEECOFIN ACQUISITION CORP. III	Director/Board Member	2023-06-16
Sol Systems LLC Sol Systems LLC Engineering & ConstructionIndustrial Services Develops, owns and operates solar projects	Chief Investment Officer	2021-07-31
CleanChoice Energy, Inc. CleanChoice Energy, Inc. Alternative Power GenerationUtilities Generates, supplies and develops solar energy projects	Corporate Officer/Principal	2020-04-30
RBC Capital Markets LLC RBC Capital Markets LLC Investment Banks/BrokersFinance Provides brokerage services	Corporate Officer/Principal	2014-12-31
IEG (Deutschland) GmbH IEG (Deutschland) GmbH Investment Banks/BrokersFinance Engages in investment banking; provides M&A advisory services	Chief Executive Officer	2012-12-31

See the detail of Mary Mandanas's experience

Training of Mary Mandanas

Experiences
Positions held

Active

Inactive

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Private companies

See the detail of Mary Mandanas's experience

Connections

1st degree connections

1st degree companies

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Female

Members of the board

Executives

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Linked companies

Private companies	13
Citigroup, Inc. Citigroup, Inc. Major BanksFinance Provides retail, investment, commercial banking, brand cards, securities sale & exchanges services	Finance
Utility Corp. Utility Corp. Investment Trusts/Mutual FundsMiscellaneous Acts as Closed-End Investment Fund/Investment Trust	Miscellaneous
Vanderbilt University Vanderbilt University Other Consumer ServicesConsumer Services Functions as a College/University	Consumer Services
RBC Capital Markets LLC RBC Capital Markets LLC Investment Banks/BrokersFinance Provides brokerage services	Finance
University of South Carolina University of South Carolina Other Consumer ServicesConsumer Services Functions as a College/University	Consumer Services
Bank of America, NA (Charlotte, North Carolina) Bank of America, NA (Charlotte, North Carolina) Major BanksFinance Operates as a nationally chartered commercial bank	Finance
University of South Carolina Business Partnership Foundati
IEG (Deutschland) GmbH IEG (Deutschland) GmbH Investment Banks/BrokersFinance Engages in investment banking; provides M&A advisory services	Finance
Onyx Renewable Partners LP Onyx Renewable Partners LP Alternative Power GenerationUtilities Offers clean energy and decarbonization solutions	Utilities
Sol Systems LLC Sol Systems LLC Engineering & ConstructionIndustrial Services Develops, owns and operates solar projects	Industrial Services
CleanChoice Energy, Inc. CleanChoice Energy, Inc. Alternative Power GenerationUtilities Generates, supplies and develops solar energy projects	Utilities
TortoiseEcofin Acquisition Corp. III TortoiseEcofin Acquisition Corp. III Financial ConglomeratesFinance Operates as a blank check company	Finance
Energy Vault Holdings, Inc. Energy Vault Holdings, Inc. Electrical ProductsProducer Manufacturing Designs and constructs energy storage products	Producer Manufacturing