Mark A. Barnett

Co-Chair, Business Department

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 has a leading business law practice focused on the energy and climate solution sectors, advising emerging and high growth companies on governance and strategic matters, corporate and project financings, mergers and acquisitions, intellectual property strategy, joint ventures and non-traditional partnerships, and industry-specific regulatory challenges.

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

Mark’s prior experience includes time in government as counsel to the Connecticut Clean Energy Fund, a quasi-public state agency that supports the development of clean energy technology (now known as the Connecticut Green Bank). 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 advises a number of innovative initiatives at the intersection of charitable and mission-driven activities in cleantech and climate change mitigation sectors. Among other activities, he advises the PRIME Coalition, CrossBoundary Energy Access and the Grantham Foundation as pro bono counsel. 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 is co-chair of the firm’s Business Department, where he works to further the strategic goals of the department and Foley Hoag.


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

Bar and Court Admissions

  • Massachusetts
  • Connecticut


  • ERISA Fiduciaries May Factor Climate Change Issues Into Economic Analysis of Investments (December 24, 2015)
  • Massachusetts DOER Releases Draft SREC II Regulations (January 10, 2014)
  • House Passes Combined Renewable Electricity/Energy Efficiency Standard (July 8, 2009)
  • Recovery Act Essentials: New Funding for Solar Energy Announced (June 10, 2009)

Honors & Involvement

  • Ranked by Chambers USA: America's Leading Lawyers for Business as one of Massachusetts' leading Energy & Natural Resources lawyers (2021, 2022) 
  • Recognized as a ‘#Solar100 Thought Leader’ by kWh analytics (2018)
  • Listed as one of ‘The Top 100 People Shaping Cleantech on Twitter’ by CleanTechnica (2015) 
  • Listed as a ‘Rising Star’ in Super Lawyers' Massachusetts Rising Stars: A Comprehensive Listing on the Best Young Lawyers in Massachusetts (2009, 2013-2014)
  • 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

Speaking Engagements

  • 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, “Solar + Storage,” Foley Hoag LLP and NECEC (May 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, “Energy Storage Forum,” NECEC and Foley Hoag LLP (September 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)