A1 Sun, Inc. review

Positive reviews:

“I’m in the last two days of completing a system here in El Cerrito. I’m a private home inspector and have known Larry for many years in a professional capacity. Reuben is the new person in charge and is already doing an outstanding job. The level of professionalism and care for the client within this institution is extraordinary. We get so used to working with people who are subpar, that when you work with someone who is first rate, especially an ensemble cast like this, it sort of bowls you over. Everyone is extremely knowledgeable and patient and friendly and the job gets done without any unnecessary hitches. Their communication is terrific. The email or text about everything on a regular basis so you’re never wondering what’s going to happen or when. As a client and a professional, I cannot recommend this company more highly. Matt Cantor AC CANTOR INSPECTIONS” – Matt C. ⭐⭐⭐⭐⭐ December 10, 2025

“A1 Sun is a true local gem, committed not only to providing excellent project management and customer service, but also to hiring, fairly compensating, and retaining a skilled and dedicated staff in Berkeley. The Giustino family’s lifelong passion for solar, including an enthusiasm for education as well as installation, has clearly infused the ongoing enterprise with a cohesive sense of collaboration and commitment. I had a VERY complex design and installation project, requiring careful and consistent long term scheduling and coordination under various tight PGE deadlines. A1 Sun came through with flying colors. Could I have found some fly by night discounter with a lower quote? Possibly, but I would have been nuts to pass up the true value that A1 Sun delivered, and it’s a good feeling to support such a dedicated local enterprise. Thanks folks, A+ to A1, and Solar Power to the People!” – B.D. O. ⭐⭐⭐⭐⭐ April 10, 2026

Negative reviews:

“Left multiple phone messages trying to arrange solar panel and backup battery installation. They never called back.” – Richard H. ⭐☆☆☆☆ January 20, 2023

“The company itself, A1, and the individuals in it are great people to work with, very helpful and professional. However, they are associated with Enphase who provides them with equipment and the software that runs the system. The hardware is fine, the software is awful. They are trying to implement AI and they are not succeeding, to the detriment of A1 customers. The software is so bad that its costing customers lots of money by routing power to PGE when it’s cheap and getting power from PGE when it’s very expensive, the reverse of what they should be doing. You would be better served is you looked elsewhere.” – Armando P. ⭐☆☆☆☆ January 7, 2025

Positive reviews:

“It went very well. During negotiations, when we were looking at three different companies, A1 hung in there, knowing there was competition, and answered all our questions quickly and thoroughly. Once they were chosen to do the work, they completed it well within the agreed timeframe. Their people were competent and easy to work with. We would definitely hire them again.” – Douglas A. ⭐⭐⭐⭐⭐ April 2018

“Hi, We recently installed 14 solar panels on our south-facing roof in Albany. I started by checking out about ten solar installation companies. Based upon their on-line presentations and reviews, I narrowed the field down to five companies. I asked each company to make us a proposal. Some companies came by in person, and others made their proposals based upon on-line projections of our roof. From these proposals I learned that there was a variety of arrays to chose from, a myriad of solar panels and productivities to choose from, and inverters, micro-inverters, and optimizers to choose from. I kept asking the five companies for new (and more productive) options. One thing I learned from all five was that it was not cost-effective to oversize the system. Over a few weeks I received 21 different (ascending) proposals from the five companies. Ultimately, I based my decision on Confidence in the Company, and System Cost per installed watt. A1 Sun was my first choice of a company and they delivered. I cannot recommend A1 Sun high enough! I signed a contract with them on a Monday and I was producing solar on a Friday eleven days later. I can’t say enough about the installation process. A1’s technicians arrived on time, were thoughtful and courteous, addressed our concerns, and cleaned up after themselves on a daily basis. The installation was completed far in advance of our expectations.” – George P. ⭐⭐⭐⭐⭐ May 2017

Positive reviews:

“We had a very positive experience with A1 Sun for installation of solar with Enphase battery backup. We replaced the roof at the same time, and I initially contacted larger installers who would quote for the roof plus solar. I’m glad we also contacted A1 Sun and local roofers (choosing to work with Nicholas Roofing). A1 pricing was comparable to other quotes, and importantly was never inflated for other issues as they arise. They worked out a layout on our south-facing rooflines to maximize the number of panels by choosing slightly smaller panels that packed the space more efficiently. (Our other quotes were not done at that same level of detail to figure that out.) A1 worked seamlessly with Nicholas Roofing, and our contractor and electrician doing contemporaneous work. This meant that A1 had someone out at our house at several random times prior to the official installation, including running an electrical conduit through the basement and moving roof vents. They also handled all the interactions with the City of Berkeley and with PG&E. If you talk to the folks at A1, those aren’t salespeople, but the same knowledgeable people who will do your install. Highly recommended.” – David Schlegel ⭐⭐⭐⭐⭐ October 2025

“We wanted a solar electric system that was future-ready, with enough power to start making our home fossil-fuel-free, and A1 Sun delivered. They were very informative in the assessment/proposal phase, and mindful of details in the installation phase. Their rates were competitive. We were also installing a new roof and they seamlessly coordinated with the roofing company. Their designer was able to work around some challenging roof geometry to give us the system size we wanted, and it is producing like gangbusters. The Enphase Enlighten app (when consumption monitoring equipment is installed) will produce data on electrical production, consumption, importing from and exporting to PG&E. It was a great experience from beginning to end, and we highly recommend their services.” – Colin Thomson ⭐⭐⭐⭐⭐ 2025

Negative reviews:

“I just got off the phone with “”Ferrar””, Service Manager, about an Enphase warranty repair. A1 Sun , the Enphase Platinum contracted installer in Berkeley, will not effectuate Enphase labor/product warranty repairs per what Enphase contracts. Their estimated surcharge for an estimate to determine what repairs are needed is a minimum of $550 plus $200 per hour after two hours. In my case where the system electrical defects are known, to replace out an IQ Controller 3, the time to do this will be “”a half day””, and the total cost in addition to the, apparently, $200 Enphase offers as compensation for warranty labor for all of this according to A1 Solar. Ferrar kept saying, “”…we did not do the original installation…”” as if this has much to do with effectuating a labor/product repair or “”vetting”” a customer, basically judging me because after he told me there would be these surcharges because of the “”cost of doing business in the Bay Area””, I asked specific questions about what those costs would be, and he apparently did not like me doing this, so he said, “”we won’t do this work””, which I reframed as, “”so you don’t want me to be your customer?””, which he refused to answer. A1 Sun refuses to “”earn””, in addition to whatever Enphase pays for full warranty coverage, their full standard fees of $550 minimum plus $200/hour, and on top of that, judge per their own criteria, any person who happens to need their services of whether they meet the “”A1 Sun customer criteria”” per Ferrar… quite audacious of them when they’re getting their standard labor rates on top of Enphase warranty reimbursement. This is A1 Sun, Inc., a Platinum Enphase dealer, who 3/4ths of the way through the call, told me they were recording the call without my authorization.” – Mark Pirie ⭐☆☆☆☆ June 2025

Market Leader

With an overall third-party rating of 4+ and positive feedback across more than 10 reviews from different platforms, A1 Sun, Inc. is distinguished as a Market Leader. They’ve established themselves in 1 state, which points to solid customer relationships in these markets. If you’re looking for an experienced solar provider known for both quality and reliability, A1 Sun, Inc. stands out as a premier choice in the solar installation industry.