About A1 Sun
Our History
A1 Sun is family owned and managed. Larry Giustino began working in solar more than 50 years ago, and has been a part of every major evolution in the technology. Our team of knowledgeable installers and design professionals come from within our local community. Our community is our customer base. We are proud to have installed more than 5,000 Megawatts of renewable power in the Bay Area (and counting!)
Our commitment to the planet
An Alameda County Certified Green Business since our first year in business, we install the same components for our clients that we use ourselves. Our commitment to the environment extends beyond what we do, to how we do it. We precycle, then recycle everything that is possible to recycle. We minimize waste and appropriately dispose of what we cannot recycle. We only get one planet! It is up to all of us to save it.
Our Commitment To You
- Treat every home like our own.
- Quality over quantity.
- Every job handled in-house, by a well-trained team.
- Be a good neighbor.
- Build to last forever.
Meet The Family
Larry Guistino
In 1965 at the age of 11, Larry manufactured a photovoltaic cell through a Bell Telephone Lab school program in San Diego, CA. Starting with a raw silicon ingot and after weeks of preparation phases, the polished and doped pie shaped quarter silicon wafer produced about 0.5 DC volts in full sunlight. It worked perfectly converting sunlight into electricity and was a brilliant success. As a consequence, Larry was already convinced of the efficacy of solar electricity four plus decades ago as a elementary school student. After graduating from UC Berkeley, he attended Dr. Marshall Merriam’s UC Solar Engineering graduate seminars. He went to work at Solar Station, Inc., designing and installing solar thermal systems in the 70’s and 80’s. He supervised all phases of the design and installation of the UC Berkeley Student Co-op solar thermal systems, still working today. US Federal Solar Tax Credits were reinstated in 2005. On Kathleen’s insistence, Larry installed solar photovoltaic modules on their home and office. It felt so good, Larry re-entered the solar field selling, designing, and installing solar. With long time associate Paul Cooper, Kathleen and Larry founded A1 Sun, Inc. in 2007 to meet the growing solar demand of residential and commercial clients.
Kathleen Guistino
Kathleen earned a BA from UC Berkeley, an MA, and NBCT degrees. After spending much of her career developing the youth of Berkeley as a public school teacher, she became a founding partner of A1 Sun. From A1 Sun’s inception, Kathleen’s work has been integral. She manages the finances and daily business operations and contributes her personal vision to the company’s renewable energy goals.
Ben Guistino
Ben has worked in the family business since its inception in 2007, first as an installer, then project manager, and now VP of Operations. His strong passion and extensive experience in the solar industry have led to assuming a role as a leader in the industry. His experience and consultation is sought by California Solar industry lobby groups, as well as major corporate suppliers such as Enphase. This industry is his passion. Bay Area homes are his laboratory, and he loves to continually push the boundaries of what is technically possible.