Free bill analysis - bring a power bill, get the production math for your actual roof, panel brands like Qcells and REC compared side by side
If the pitch starts at your door and ends with "sign tonight for the special," sleep on it. The sun will still be there tomorrow; so will we.
Fast, Reliable Solar Panel Installation Across Fairfax
Solar panel installation in Fairfax runs $18,000 to $38,000 for a whole-home system before the 30% federal tax credit, and most jobs take two to four days on the roof. The bigger variable here isn’t panel cost. It’s whether your hillside lot, mature tree canopy, and older electrical panel require the kind of design work that separates a system that actually produces from one that just looks good on a brochure. Gus Petrakis has been quoting real numbers off real utility bills since 2011, and he’ll tell you straight if solar makes sense for your particular stretch of this valley. Call (877) 550-6892 and bring a bill. We’ll bring the math.
Why Gus’s Solar Is Fairfax’s Preferred Solar Panel Installation Company
Fairfax is a small town with a long memory. Homeowners here talk. They remember which installers showed up on time, which ones left flashing that leaked, and which ones answered the phone in year three when something tripped offline. We’ve built our reputation in Marin County the slow way: one roof at a time, with Gus’s name on the work and his cell number on the invoice.
The homes in Fairfax are not easy. A 1958 hillside rancher off Bolinas Road, a 1965 split-level near Deer Park, a 1940s cottage up Cascade Drive. Each one has its own pitch, its own shading, its own quirks. We’ve stood on enough of these roofs to know that a satellite image will not tell you the truth about what that redwood over the ridgeline does to your afternoon production. That is why every Fairfax estimate starts with our own crew on the roof or in the yard, not with a sales app. We serve the 94930 and 94978 zip codes directly, and a live person answers the phone 24/7. Not a voicemail, not a ticketing portal. A person.
The town’s first-in-the-nation plastic bag ban in 2007 tells you something about the people who live here. They care about doing things right, and they expect the same from the contractor they hire. We honor that. The 90-Day Done Right Promise is in writing on every solar job, and the crew on your roof is Gus’s own crew: background-checked, uniformed, and accountable to a guy whose address is published and whose name is on the building.
Our Solar Panel Installation Services in Fairfax
Rooftop Solar Installation
Most Fairfax rooftops are not wide-open, south-facing planes. They are cut up by dormers, interrupted by skylights, or tilted by a hillside that dictated the original roofline. We build systems around the roof you actually have. That means designing panel layouts that work with dormers and valleys, flashing every penetration properly, and sizing the array to the usable square footage rather than forcing more panels than the roof can honestly hold. We install rooftop systems that produce, not rooftop systems that impress the neighbors.

Solar System Design & Permitting
Fairfax sits in an inland valley ringed by forested ridgelines. Mornings and late afternoons stretch shadows far beyond what an azimuth chart predicts. That is why our design process starts with an in-person shade assessment, not a satellite model. We map the actual shade cast by the redwoods, coast live oaks, and bay laurels on your specific lot, then build the system around what the sun actually does. Permitting goes through the town’s building department, and we handle the full package: structural review, electrical plan, everything.
We also work around Fairfax’s tree-protection rules. We will never tell you to cut a healthy native tree to make solar work. Instead, we design with microinverters and optimizers that harvest intermittent light from each roof section independently. A string inverter loses the whole string when one panel goes dark. That is a dealbreaker under a redwood canopy. We design systems that do not fight the trees.

Solar Panel Replacement
Older systems around Fairfax, especially the ones installed when solar was newer in Marin, are starting to underperform. Some have string inverters that were never the right fit for this tree-heavy town. Some have panels that have degraded faster than their warranty promised. We replace panels and inverters, and we do it without pretending the old mounting hardware is always reusable. Some of those 2010-era racking systems need full replacement. We’ll tell you before we start, not after we find it.

Roof-Mount & Tile Roof Solar
Fairfax has its share of tile roofs, particularly on the mid-century homes that went up in the 1950s and 1960s. Tile work is unforgiving. Broken tiles, cracked flashing, and water intrusion are the failure points that show up six months after a sloppy install. Our crew knows how to lift tile without cracking it, how to flash penetrations so they stay dry through Marin winters, and how to mount racking that holds through the kind of heavy downpour Fairfax gets each year. We do not hand this work off to a sub. The same crew that shows up for the quote is the crew on the roof.
For the full picture on what we do, visit our Solar Panel Installation hub. This page is about Fairfax specifically, because that’s the town we’re writing for.

What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Fairfax
We work with the equipment that actually performs under a redwood canopy. That means Enphase microinverters, SolarEdge optimizers, and FranklinWH for battery backup. These are the brands that let each panel produce independently, so one shaded section doesn’t drag down the whole array. We stock common parts and service these brands regularly for Fairfax homeowners, which matters when an inverter throws a fault on a Saturday and you want it handled before the next sunny week. We’re familiar with Tesla and other major brands too, but for the shade-heavy lots up Cascade Drive and around White Hill, the microinverter and optimizer architecture is what we recommend most often.
Common Solar Panel Installation Problems We See in Fairfax Homes
- String inverters failing under shifting shade. Dense redwood and oak canopy creates shade that moves all day. A single shaded panel pulls down the entire string. We regularly replace string systems in Fairfax with microinverter or optimizer layouts that let each panel work independently.
- Legacy 100-amp electrical panels blocking interconnection. Homes built between the 1940s and early 1970s often still have 100-amp service. The town’s building department will not approve solar interconnection without a service upgrade to 200 amps in most cases. We spot this early and factor it into the quote, so it’s not a surprise line item mid-project.
- Satellite-only shade estimates missing the ridgeline shadows. Fairfax sits in a valley. The surrounding hills extend morning and late-afternoon shadow coverage well beyond what satellite modeling predicts. Production estimates built on satellite data alone almost always overpromise here. That’s why we do in-person shade assessment before we quote a production number.
- Roof penetrations leaking after rushed installs. Fairfax gets real rain. Flashing that wasn’t done properly shows up in the next winter storm. We flash every penetration correctly the first time, and the 90-Day Done Right Promise means if something is wrong, one call brings Gus back.
Pricing for Solar Panel Installation in Fairfax, CA
A whole-home rooftop solar installation in Fairfax typically runs $18,000 to $38,000 before the 30% federal tax credit. Here is a realistic breakdown of what we see across the 94930 and 94978 zip codes:
- Rooftop installation, 6-8 kW range, microinverters: $18,000-$24,000
- Rooftop installation, 9-12 kW range, microinverters or optimizers: $27,000-$38,000
- Electrical panel upgrade from 100-amp to 200-amp, when required: $3,500-$6,000
- Tile roof racking adder, per roof section: $800-$2,500 depending on tile type and pitch
- Solar panel replacement, per panel (labor and disposal included): $575-$1,100
These ranges reflect what we actually quote here. No door-knocker math, no brochure estimates. We quote the year-25 output, not the day-one brochure number. Bring a bill to your estimate and we will build the quote around your actual usage and Marin’s export rates. You’ll get a number, not a pitch. And you can take two weeks to think about it. The price will be the same. Call (877) 550-6892 for a free estimate. No signature wanted tonight.
We Also Serve Cities Near Fairfax
We work throughout central Marin, from San Anselmo and San Rafael to Kentfield and Lucas Valley-Marinwood. Many of those neighborhoods have the same hillside shading and older housing stock as Fairfax, and the same need for honest design work. If you’re in one of those towns, the approach is the same: in-person assessment, real numbers, no pressure. You can learn more about our work across the region on our Fairfax page.
Serving Fairfax, CA - Our Local Coverage Area
We’re based in the Fairfax area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs - Solar Panel Installation in Fairfax
Fairfax protects its native trees, and the permit process for removal or trimming is strict. In practice, we never ask you to cut a branch. We design systems with microinverters or optimizers that harvest whatever intermittent sunlight reaches each roof section independently, so the trees stay and the system still produces. If you’ve been told by another installer that a tree has to go, get a second opinion. Estimates for a second look are free, and we’ll show you the production math both ways. Call (877) 550-6892.
Many Fairfax homes built between the 1940s and early 1970s still have 100-amp service, and yes, most will need a 200-amp panel upgrade before the town approves solar interconnection. A service upgrade in Fairfax typically runs $3,500 to $6,000. We identify this during the estimate, not after you’ve signed, so the quote you get is the quote that holds. Bring us a recent bill and we’ll tell you exactly where you stand. Call (877) 550-6892.
Fairfax sits in an inland valley ringed by forested ridgelines. Hills to the east and west stretch morning and late-afternoon shadows well beyond what azimuth charts and satellite images predict. A satellite model might show clear sky at 4 p.m. while the ridge to the west has already thrown your entire array into shade. We measure the actual shade cast on your roof across the day, because an estimate built on satellite data alone overpromises, and overpromising is how homeowners end up paying for a system that never pays them back. That is not how we work. Call (877) 550-6892 for a real assessment.
Microinverters like Enphase or DC optimizers like SolarEdge are the right call under Fairfax’s dense redwood and oak canopy. A traditional string inverter ties all panels together, so one shaded panel drags down the entire system. Microinverters and optimizers let each panel produce independently, which matters when shifting shade moves across your roof all day. On a hillside home off Scenic Road, we used Enphase microinverters on the west-facing section specifically because that was where intermittent sunlight actually landed, and the system performed as quoted. Call (877) 550-6892 and we’ll explain the difference in plain language.
Yes, in most cases. Fairfax is warmer than coastal Marin on sunny afternoons, and those clear valley afternoons are a genuine solar asset. The key is designing for the shade that surrounds them. On an unshaded southern roof, solar pencils out quickly. On a heavily shaded hillside lot, it may take longer or require a different layout. We’ll give you the year-25 production number, not the day-one brochure figure, and you can decide with real math in front of you. Call (877) 550-6892 for a free, no-pressure estimate. Take two weeks. The price will be the same.
Written by Gus Petrakis, Owner at Gus’s Solar, serving Fairfax and Marin County since 2011.
Ready to see what your roof can actually produce? Call (877) 550-6892. Bring a bill. We’ll bring the math. No pressure, no signature tonight, no tree-cutting requests. Just a real number from a local crew that answers the phone.






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