GAF - Key Persons


David Kaltsas - COO

Job Titles:
  • Chief Operating Officer
  • Member of the Leadership Team
David is all about making solar happen. For him, the union of solar and roofing is the best way to increase solar adoption that he's seen in his 20 years of working in energy infrastructure. He has an extensive background in solar with specific expertise in the commercial and industrial space, serving as COO of Sol-Wind and President and COO of SunWize. He holds a BA in Global Change and Transformational Leadership from the University of St. Thomas. His favorite roof is on the headquarters of Mitsui & Co in Tokyo, which has solar on top and a courtside view of the Imperial Palace.

Dr. Gabriela Bunea

Job Titles:
  • Member of the Leadership Team
  • Chief Solar Innovation Officer
Gabi creates world-changing technology and believes in combining solar energy generation with sustainable building materials. She brings 20 years of extensive technical experience and leadership in the solar and microelectronics industries to GAF Energy, most recently as Vice President of Research, Development and Deployment at SunPower Corporation. Prior to that, she held multiple roles managing Module Research, Development, Deployment and Product Design at SunPower, and previously worked as a Member of the Technical Staff in the Microelectronics Division at Lucent Technology. She holds a Ph.D. in Physics from Boston University and is an active member in IEEE Women in Engineering. Her favorite roof is the one crowning the Marina Bay Sands hotel in Singapore, an exemplar of what's possible in using ecologically-minded building materials.

Jason Barrett

Job Titles:
  • Member of the Leadership Team
  • Senior Vice President, Sales
Jason believes using the sun's energy is key to keeping the planet safe for future generations. Prior to his sales and commercial tax equity roles at GAF Energy, he served as Chief Commercial Officer of Sol-Wind as well as a founding partner of Paladin Strategic Partners and has an extensive background in structured finance and asset management with senior positions at firms including Merrill Lynch, Credit Suisse, Fannie Mae, Morgan Stanley and the Hartford Insurance Group. He has a BBA in Finance and International Business from Howard University where he was a Trustee and ITT Hartford Scholar and an MBA from Cornell University where he was a Robert Toigo Fellow. His favorite roof is the one on the Westmont Industries Distribution Center at the Port of LA, which has 50,000 solar panels on it (that he led the financing for).

Keally DeWitt

Job Titles:
  • Member of the Leadership Team
  • Vice President, Marketing & Public Policy
Keally comes to solar with the conviction that carbon-neutral is the new black. She started in renewables as the Head of Marketing for the largest solar company in the Northeast before moving into marketing and public policy leadership roles at Sunrun and SunPower. As the National Organizing Director of The Alliance for Solar Choice (TASC), Fortune magazine described the netroots work she pioneered as "radically changing" political advocacy through digital technology. Prior to joining GAF Energy, she served as Head of Marketing at Mosaic. She has a BA from Brown University. Her favorite roof is the one she used to sit on as a kid, listening to the cicadas, outside her bedroom window in Southwest Ohio.

Lucy Zhao

Job Titles:
  • Member of the Leadership Team
  • Vice President, Legal & Business Affairs
Lucy brings legal expertise to the company's day-to-day business, as well as to its longer term planning. Prior to joining GAF Energy, Lucy held a senior counsel role at Standard Industries, our parent company, where she advised on a range of matters including tax equity investments, corporate finance, and strategic transactions. Lucy joined Standard from Kramer Levin Naftalis & Frankel LLP, a New York-based law firm, specializing in M&A and private investments. Lucy holds undergraduate degrees in economics and mathematics from MIT, and a law degree from The George Washington University Law School. Lucy's favorite roof is the glass dome that sits atop the U.S. Botanic Garden Conservatory, a place she frequently visited while living in D.C. as a law student.

Martin DeBono - President

Job Titles:
  • Member of the Leadership Team
  • President
Martin began his career in alternative energy in a somewhat unorthodox place: as a decorated officer on a nuclear submarine in the U.S. Navy. He has held sales and marketing positions at various tech companies, including Cisco, Siebel, Insightful and Pure Networks. Prior to running GAF Energy, he headed SunPower's residential North American business and global commercial business and served as President of SunPower Capital. He is also a member of Phi Beta Kappa, and has a BS from the University of North Carolina and an MBA from Harvard University. His favorite roof is the top of his bike helmet when he's out on the mountain bike trails in British Columbia.

Ralph Robinett

Job Titles:
  • Member of the Leadership Team
  • Senior Vice President, Manufacturing & Supply Chain
Ralph brings the world-changing innovations of GAF Energy to mass production. Before joining GAF Energy, Ralph held senior leadership positions in global operations, manufacturing, engineering and quality in the solar, electronics, and semiconductor industries. Most recently, Ralph was the VP of Operations at Celestica. Prior to that, he was the VP of Operations at SunPower Corporation, where he led SunPower's solar panel manufacturing and operational excellence organizations. He has a BS in Physics from the University of Texas at Austin. His favorite roof is on his house in Austin, where the solar panels he made are delivering clean energy every day.

Reynolds Holmes

Job Titles:
  • Member of the Leadership Team
  • Vice President, Product
Reynolds' personal mission is to democratize renewable energy. The ability to unlock solar through the roofing channel represents the best opportunity to accomplish his mission. Prior to joining GAF Energy, he held senior leadership positions at both SolarCity and Tesla, where he led launches of new energy products, services, and experiences designed for scale. He earned an MBA from the University of Oregon and a BS in electrical engineering from Yale University. As a former Ivy League track champion, his favorite roof is the frosted glass roof over Coxe Cage, Yale's century-old indoor track and field facility.