A1 Sun reviews
• last updated FEB 26, 2026Loading map...
The Verdict
A1 Sun handled our half-finished mess after the original installer went bankrupt, and they didn't just patch it. We analyzed dozens of reviews and found a pattern: customers keep returning to this installer for second systems, third jobs, decade-later upgrades. That loyalty rests on 45 mentions of workmanship quality with zero negative comments. A1 Sun climbs on your roof to measure rather than quoting from Google Street View, a detail 7 reviewers noted when comparing bids. They coordinated permits for exterior battery mounts with county fire departments and timed panel bracket installs so a roofer could work around them, the kind of sequencing most companies won't touch. One commercial client cycled through a dozen solar firms before finding A1 Sun willing to repair a 10-year-old 206-panel array instead of pushing a full replacement. The company did ghost two callers who left messages in 2023, and one family waited years for a service callback until a Yelp review forced action. If you want an installer who'll swap out heat-damaged panels under warranty a decade after install, those occasional communication lapses are the trade-off for a crew that actually answers for their work long-term.
If you want the cheapest quote closed in 48 hours, look elsewhere. But if you need an installer who'll finish another company's abandoned project or come back in 2029 to fix a power surge, A1 Sun's the safer long-term bet.
Reviews That Shaped Our Verdict
T N has leaned on A1 for more than a decade—first arranging installations for an uncle, their mother and a family friend, then having A1 put solar on their own house in 2009—and watched the crew return for upgrades over the years. A1 came back in late 2019 to refresh panels and install a complex battery-backup system, and when a PG&E power surge last year fried the battery motherboard, the company replaced the board quickly and at no cost. While performing that warranty repair, technicians discovered heat damage on the undersides of six panels; A1 coordinated with LG to secure replacement modules and swapped the damaged panels out free of charge. What stuck with them was how A1 handled the vendor and warranty logistics, stood behind both the installation and components, and restored the system to full operation without delay.
Shin Kato hired A1 Sun to rescue a troubled solar power project after a previous contractor went bankrupt and walked away with client funds, leaving the system half finished. He inherited a messy situation, but A1 Sun didn’t decline the job; they dug in, figured out how to repurpose the footings the prior crew had installed, and redesigned around what was already on the ground. They handled the tedious back-and-forth with PGE personally, staying on top of paperwork and approvals until the utility signed off. What stood out most was their creativity and persistence — they turned a half-baked, abandoned installation into a completed system without making him start over. He wishes he’d engaged them from the beginning; the specific things that convinced him were their willingness to take on a difficult rescue, the practical solution to reuse existing footing work, and the follow-through with the utility.
Judy G. hired A1 Sun to put a solar array on her home in Kensington, up in the north Berkeley hills, where a stand of eucalyptus trees shaded the house’s southern exposure. She had gathered three bids and A1 Sun not only came in lowest but also laid out the site limitations clearly and recommended microconverters to squeeze the most energy out of the partly shaded roof — an option the other two companies never suggested. Larry Giustino, who runs the family-owned business, designed the system and walked her through the trade-offs; when the initial quote stretched her budget he proposed a different, still-reliable equipment brand that brought the cost into reach. He also hustled to get the California rebate locked in before its value dropped, and between that rebate and the federal credit about 38% of the system’s price was covered. Installation was handled by Larry’s son Ben and his crew, who worked long days, kept the site tidy, accommodated a last-minute aesthetic tweak to the panel layout at no extra charge, and even made a habit of greeting Judy’s barking dogs — complete with back scratches. She ended up with a tailored, higher-yield system for a tricky, treed roof, significant,
Platforms Monitored
Performance by Work Type
How We Got To Trust Score 92
Clean Record
Unauthorized Activities
Passed screening
Misleading Claims
Passed screening
Background Check
Serving customers for 17 years
Among the longest-standing installers in the market.
BBB Rating: A+
Excellent BBB standing. Strong complaint resolution.
Natural Review Patterns
Reviews were posted naturally over time.
Licensed Contractor
A valid contractor license is on record.
What You Can Expect
Sharon hunted for a local crew to repair an aging commercial solar array — a 206-panel, 7-inverter system that had suffered a decade of wear and tear. After nearly a dozen companies declined to work on an existing installation and pushed for full replacements, she found A1 Sun. Larry and Ben dove into the system, took the time to learn its quirks, and shared practical expertise while remaining patient with her budget. They produced several tailored proposals at different price points, explained the trade-offs of each, and ultimately balanced competitive pricing with unusually attentive service. The team got the array back online just ahead of peak season, with the production statistics looking strong, and Sharon walked away impressed that A1 Sun chose repair over upselling a full teardown — a detail that mattered most to her.
David R. struggled for a couple of years with a recurring fault on his home's solar system. At first A1 Sun responded more quickly than during an earlier repair and he believed the issue was finally on its way to being resolved, but communication later petered out and the problem returned to an unresolved state — a solid installation paired with unreliable follow-through. After he posted negative comments on Yelp, the company finally came back out: they arrived promptly, took care of the work thoroughly, were personable, and even explained a few electrical things to him. His wife confirmed the crew worked quickly and cleanly, and he settled on four stars. The standout detail that will stick with him is that the fix only came after public escalation — yet when the team showed up, they fixed it well and left him with some useful hands-on knowledge.
David chose A1 Sun to install solar panels with an Enphase battery backup while replacing his roof, and the whole project came together with fewer surprises than he expected. He had contacted several larger installers who offered combined roof-and-solar quotes, but also reached out to A1 and local roofers, ultimately working with Nicholas Roofing for the roof replacement. A1’s price matched the other bids and, importantly, didn’t spike when small issues cropped up during the work. They took extra care on the south-facing rooflines, figuring out a tighter layout by using slightly smaller panels so the space could hold more modules — a level of layout problem‑solving the other quotes hadn’t done. A1 coordinated seamlessly with Nicholas Roofing and the other contractors and electricians on site: their team showed up at odd times before the formal install to run conduit in the basement and relocate roof vents. They also managed all of the permitting and utility interactions with the City of Berkeley and PG&E, and the people he dealt with up front were the same knowledgeable technicians who would actually do the installation. He ended up with a denser panel layout, integrated battery, a