Barnett

Mark A. Barnett

Partner
Co-Chair, Energy & Climate Group
Co-Chair, Impact Investing Group
Boston

Drawing on my years of practice, both in government and the private sector, I advise climate innovators, developers and investors across all aspects of the climate and energy ecosystem.

Mark Barnett is Co-Chair of Foley Hoag's Energy & Climate Group, which he co-founded almost two decades ago as one of the first dedicated practices supporting innovators across the full lifecycle of the energy transition. During the course of his career, Mark has been a leader in advising breakthrough energy technology companies and venture investors, as well as developers and financers of clean energy infrastructure at scale. Mark has also supported some of the most impactful nonprofit and ecosystem building organizations supporting the transition to a sustainable climate future.

Mark has a unique energy and climate focused practice that ranges from counseling emerging and growth-stage climate companies and investors, to advising clean infrastructure developers, sponsors and investors, including tax equity investors, and also includes advising leading nonprofit entities in the sector.  

Mark advises clean energy and infrastructure project sponsors and developers in all aspects of project development, acquisitions, financings, fund formation, partnerships, joint ventures and regulatory issues. His experience includes tax equity portfolio financings, debt financings (including back leverage transactions), complicated joint ventures, various M&A transactions and innovative financing vehicles. Mark also serves as investor and lender counsel in distributed renewable energy financings. His project finance and development experience includes solar, wind, energy storage, waste-to-energy and other waste to value, innovative wastewater treatment and other clean energy and clean infrastructure projects.

Mark also has an active practice advising emerging companies, venture capital funds and impact investors in the ClimateTech space. Having served as Head of Business Development and General Counsel for an innovative ClimateTech company spun out of MIT that was ultimately acquired by Lockheed Martin, Mark is uniquely positioned to serve as counsel and strategic advisor to emerging ClimateTech companies at every stage of development. Mark also works with some of the leading venture and investors in the ClimateTech sector and regularly advises on transactions in the sector.

Mark’s prior experience includes time in government as counsel to the Connecticut Clean Energy Fund (now known as the Connecticut Green Bank), a quasi-public state agency that supports the development of clean energy technology. Mark also served as Vice President of Business Development & General Counsel at Sun Catalytix Corporation, where he helped the company raise over $17 million in equity and non-dilutive financing and then helped shepherd the company as outside counsel through a successful sale to Lockheed Martin Corporation. Mark draws on these and other experiences in the business and governmental arena to serve as a strategic and business advisor to clients.

Mark also advises a number of innovative initiatives at the intersection of charitable and mission-driven activities in and the breakthrough clean energy and climate change mitigation sectors. Among other activities, Mark has served as outside counsel to PRIME Coalition since its founding, and also collaborated with Prime on the founding and developing of its Early Climate Infrastructure program.  Mark also serves as counsel to a range of leading innovative nonprofits entities in the sectors including CrossBoundary Energy Access, RMI and Browning the Green Space. Mark also has advised national leading groups such as the Environmental Defense Fund and Ceres on clean energy policy and climate mitigation investment strategies. In addition, he is a frequent speaker across the country on topics spanning renewable energy project finance, clean energy policy and impact investing, and spends time mentoring emerging cleantech ventures through such organizations as MassChallenge and Clean Tech Open.

Mark plays an active role in the management of the firm. He leads the firm’s Energy & Climate Group and previously served as co-chair of the firm’s Business Department.

Education

  • Yale Law School, J.D.
  • Yale University, B.A.

Bar and Court Admissions

BAR ADMISSIONS
  • Massachusetts
  • Connecticut

Experience

PROJECT FINANCINGS AND M&A TRANSACTIONS
  • Aggreko Energy Transition Solutions – a division of Aggreko, a global leader in energy solutions – in its acquisition of Infiniti Energy, a premier U.S.-based commercial and industrial solar company, from Upper Bay Infrastructure Partners (Upper Bay)
  • Impact investing firm Monarch Private Capital in the tax equity financing of a 190 MW solar project developed by Sol Systems, a national renewable energy company, to advance sustainable energy and contribute to the development of clean energy infrastructure in southern Illinois
  • Soltage in over $1 billion of equity and debt financings of solar and storage project portfolios 
  • Soltage in the sale of a majority equity interest to Igneo Infrastructure Partners and in multiple portfolio M&A transactions, including the sale of its joint venture with Basalt Infrastructure Partners holding 121 Megawatts of solar assets primarily located in North and South Carolina to Altus Power
  • Greenwood Energy in the acquisition of Saturn Power and its 1.4 Gigawatt solar and battery development portfolios, and in various tax equity, debt and M&A transactions 
  • BlueWave Public Benefit Corp in various M&A and financing transactions, including $91 million financings of a portfolio of solar and storage projects with US Bank (tax equity) and KeyBank (debt financing) 
  • Spring Lane Capital in various clean infrastructure financings, including a debt facility commitment of up to $50 million, together with a co-led Series A equity investment in EVCS Charging Solutions
  • Navisun in several tax equity and portfolio debt financings
  • The Forest Road Company as lender in a debt financing transaction with California solar developer Morpho Energy
  • CrossBoundary Energy Access in acquiring and developing mini-grids in Africa, and as investor in a project finance partnership with Mobile Power
  • Aggreko Energy Transition Solutions on the acquisition and financing of a New York community solar portfolio
  • CleanCapital in negotiation of joint ventures with BlackRock’s Renewable Power Group and CarVal Investors to acquire portfolios of operating solar energy projects
  • GoldenSet Capital Partners in connection with $50 million sponsor equity and simultaneous tax equity investments for a portfolio of Massachusetts solar projects
  • AEGON USA Realty Advisors (an affiliate of Transamerica) as a tax equity investor in two North Carolina solar portfolios totaling 100 MW and 30 MW respectively
  • Ultra Capital, a clean infrastructure fund, in fund formation and other financing transactions

EMERGING COMPANIES AND VENTURE CAPITAL
  • Spring Lane Capital as lead investor in a $115 million Series C Financing of Zanskar Geothermal
  • Engine Ventures in the $45 million Series A financing of Blue Energy, a manufacturer of nuclear power plants at existing fab yards and shipyards
  • Nth Cycle, a leader in sustainable metals refining, in its $37 million Series B financing
  • ArkeaBio, a pioneer in developing technology to reduce greenhouse gas (GHG) emissions from the agricultural sector, in:
    • its $26.5 million Series A financing
    • its $12 million Series Seed financing
  • SolidEnergy Systems, a breakthrough energy storage technology developer, in its $34 million Series C financing
  • Energetic Insurance, a managing general underwriter, in multiple transactions including its $7 million Series A financing led by Schneider Electric Ventures, with participation from MS&AD Ventures, Atlantic Global Risk, and MCJ Collective
  • Nexamp in various financing transactions with Diamond Generating Corp., a wholly owned subsidiary of Mitsubishi Corporation
  • Sparkcharge, manufacturer of electric vehicle charging units designed to eliminate the challenges of wired infrastructure, in its $23 million Series A financing 
  • Neglected Climate Opportunities, the Grantham Foundation’s climate-focused venture capital vehicle, in connection with 20+ investments, including:
    • Series Seed investment in Renewable Metals, an Australian lithium battery technology company
    • Investments in Ebb Carbon, an ocean-based carbon dioxide removal (CDR) company
    • Investment in Cache Energy Storage, a company developing energy storage technology
    • Financing of Travertine Technologies, a carbon dioxide removal and industrial chemical production company
  • The Engine and Material Impact in a $10.5 million investment in Foundation Alloy Explorations, a manufacturer of high-performance metal parts intended to make the manufacturing process more sustainable for the environment
  • The Engine in various other venture financings, including investments in EvolOH and Mantel Capture 
  • Azolla Ventures in several investments including:
    • as lead investor in a Series Seed financing for Scalvy, developer of modular electric powertrains for the e-mobility market
    • investment in Calcarea, a company focused on decarbonizing shipping through carbon sequestration 
    • Series Seed financing round of Carbon Reform, a developer of modular carbon capture devices that remove carbon dioxide from ambient air in commercial buildings
  • PRIME Coalition in its fund formation and across its various innovative financing transactions to support early-stage breakthrough clean energy technology, including:
    • Seed financing of Sublime Systems
    • Series Seed financing of Noon Energy, a developer of a rechargeable battery designed to turn intermittent renewable electricity into on-demand power
    • $7.6 million Series A financing of Leading Edge Equipment Technologies

OTHER ENERGY & CLIMATE MATTERS
  • Advised on the formation the Symbiosis Coalition, a new advance market commitment collaboration from leading technology companies including Google, Meta, Microsoft, and Salesforce aimed at supporting the development and growth of the nature-based carbon removal market

Honors & Involvement

HONORS
  • Best Lawyers
    • Lawyer of the Year (2025)
    • Venture Capital Law (2025-2027)
    • Energy Law (2024-2027)
    • Corporate Law (2026-2027)
  • Chambers USA: leading Energy & Natural Resources lawyer in Massachusetts (2021-2026); Impact Investing (2025-2026) 
  • kWh analytics: Recognized ‘#Solar100 Thought Leader’ (2018)
  • CleanTechnica: 'The Top 100 People Shaping Cleantech on Twitter’ (2015) 
  • Massachusetts Super Lawyers: 'Rising Star’ (2009, 2013-2014)
INVOLVEMENT
  • Ceres President’s Council, Member
  • PRIME Coalition, Pro Bono Counsel
  • Cleantech Open, Mentor
  • MassChallenge, Mentor
  • New England Clean Energy Council, Policy Committee
  • American Bar Association, Member
  • Ceres Clean Trillion Project, Advisor
  • Brookline Education Foundation, Board Member
  • Boston Bar Associations, Member

Events

Tech Invest 2026 Page
Event 09/09/2026
Earth Night 2026 Page
Sponsorship 05/21/2026
Boston Climate Week ClimaTech Page
Sponsorship 05/04/2026
FOAK War Stories Page
Foley Hoag Event 04/01/2026
Industry Growth Forum Page
Sponsorship 03/31/2026
Colorado Climate Week  Page
Sponsorship 03/30/2026
MIT Energy Conference Page
Event 02/23/2026
2025 Green Future Gala Page
Sponsorship 10/16/2025
Clean Tech Open Academy Page
Speaking Engagement 06/03/2025
Navigating the Inflation Reduction Act Page
Speaking Engagement 06/13/2024
Solar + Storage Page
Foley Hoag Event 05/01/2018
Energy Storage Forum Page
Event 09/20/2016

Other Events

  • Speaker, “Security & Resilience,” MassChallenge: Dual Use Symposium (October 2025)
  • Panelist, "The Next Chapter in Climate Investing: A GP-Led Conversation on Strategy, Policy, and Liquidity," Impact Capital Managers (September 2025)
  • Speaker, “Nonprofits and Solar Power,” Boston Bar Association (January 2020) 
  • Moderator, NECEC Cleantech Financial Innovation Summit (June 2019) 
  • Moderator, “Financing Solar and Storage,” Solar Power Northeast (February 2019) 
  • Moderator, “How Corporate VCs Can Spur Innovation Within Corporates and the Ecosystem: The Engie New Ventures, Redaptive, and Connected Energy Case Studies,” NECEC (December 2018) 
  • Moderator, “Emerging Trends Series: Solar + Storage,” NECEC (March 2018)
  • Speaker, “Financing Solar + Storage,” Solar Power Northeast (February 2018) 
  • Judge, InnovateMass program, Massachusetts Clean Energy Center (2017) 
  • Speaker/Moderator, “Innovative Financial Models within Renewable Energy & Energy Efficiency,” Sustainatopia (October 2017)
  • Panelist, NECEC Cleantech Financial Innovation Summit (June 2017) 
  • Speaker, “Innovative Financial Models within Renewable Energy,” Sustainatopia (October 2016)
  • Moderator, "Community Solar Financing," Solar Power International (September 2016) 
  • Moderator, “Financial Innovations at the Scale Up & Deployment Stage of Clean Energy Solutions,” NECEC Cleantech Financial Innovation Summit (June 2016)
  • Panelist, “Technology and Business Model Innovation,” BSAS Investing in Clean Energy Seminar (June 2016)
  • Panelist, “The National Energy Efficiency Registry,” ACEEE Energy Efficiency Finance Forum (May 2016)
  • Panelist, “Clean Energy After COP21,” NECEC (February 2016)
  • Panelist, “Enabling Clean Energy Implementation Through Policy, Technology/Innovation and Finance,” 21st Conference of the Parties to the United Nations Framework Convention on Climate Change (COP21/CMP11), (November-December 2015)
  • Panelist, “Investing in Solar," Sustainatopia Conference, Boston, MA (November 2015)
  • Panelist, “Development and Financing Issues,” Novogradac Financing Renewable Energy Conference (November 2014)
  • Panelist, “Navigating Climate Risk and Investing for Impact,” Ceres, Black Coral Capital and PRIME Coalition (November 2014)
  • Panelist, "Creative Solar Financing Matching Funds & Projects, "Solar Power Mid-Atlantic Conference presented by Solar Energy Industries Association (SEIA), (September 2014)
  • Panelist, “Drivers of Cleantech Innovation: Policy, Capital, and IP,” Boston Bar Association Roundtable (February 2014)