Solar in Marin County
Ongaro & Sons has worked in Marin County since the company was founded here in 1932. We are Diamond Certified, we carry a BBB A+ Rating, the C-10 electrical classification sits on the same contractor license as our C-20 and C-36 work, and our Google rating stands at 4.8 stars across 2,726 reviews. Arrays, batteries, panel work and interconnections all run out of our Petaluma headquarters, which is fifteen minutes from the Novato line and central to the whole county.
On this page
Solar alone does not work during an outage
A grid-tied solar array without a battery produces nothing during a power outage, even in full sun. Many Marin homeowners first learn this during a shutoff, and it surprises almost everyone. A grid-tied inverter is built to shut down when the utility grid goes down, for the safety of anyone working on the lines, so an array without storage goes dark along with the neighborhood while its panels sit in full sun producing nothing.
It matters more here than in most places because of what causes the outage. Under its Public Safety Power Shutoff program, PG&E takes circuits offline when fire danger is high. Because that is a planned, weather-driven event rather than a brief fault, it can run for days rather than minutes, and it lands hardest on exactly the wooded hillside and rural neighborhoods that make up so much of this county. The design question stops being how to zero out a bill and becomes how to live normally for two or three days.
So the first thing worth saying plainly about solar in Marin is that panels alone do not solve the problem most people here are trying to solve. Storage plus the right transfer equipment does. For some households a standby generator is the better fit, or the right companion to a smaller battery, and because we are a Certified Generac Generator installer as well as a solar contractor, that comparison can be made on the merits rather than on what we happen to sell.
Why a county-wide answer is the wrong answer
Marin is small on a map and unusually varied underneath. Four things change as you move across it, and each one changes the project.
Jurisdiction changes, roughly every few miles. Belvedere, Corte Madera, Fairfax, Larkspur, Mill Valley, Novato, Ross, San Anselmo, San Rafael, Sausalito and Tiburon each run their own building department, their own submittal system and their own fee schedule. Everything outside those city and town limits, which includes a great deal of the county's land and many addresses whose mail says otherwise, is permitted through Marin County Building and Safety. The county's own unincorporated Marin listing includes communities such as Mill Valley Homestead Valley, Mill Valley Strawberry and Mill Valley Tamalpais Valley, which is why a mailing address settles nothing. We confirm the authority by parcel before filing.
Climate changes at the ridge. West of the ridgeline and out toward the coast, marine air and summer fog keep cooling loads small and the sky gray until midday for much of the season. Inland, in Novato, Terra Linda, the Ross Valley and the eastern edge of San Rafael, late-summer afternoons run genuinely warm and air conditioning starts to dominate the load curve. The same array carries very different value on those two houses, and a production model that ignores the difference is describing a county rather than a roof.
The building era changes, and it predicts the work better than the compass does. More on that below.
One thing does not change: all of Marin County sits inside the Bay Area Air Quality Management District, with no partial-boundary question anywhere in the county. That matters less for the array than for what the array gets sized around, which is covered under electrification further down.
What the building era tells us before we arrive
Town cores built before roughly 1940. Sausalito's Old Town, downtown Mill Valley, the older blocks of San Anselmo, Fairfax, Larkspur and Ross, and San Rafael west of downtown. These roofs are steep, cut up by dormers and cross gables, and frequently carry more than one layer of covering because someone added rather than removed. Mature street trees put real shade on the south face by mid-afternoon. Below the roofline we routinely find services sized for a much shorter appliance list, sub-panels bolted on across several decades, and branch circuits nobody has ever traced. On these houses the array layout is rarely the hard part. The service and the interconnection point are.
Postwar tracts, roughly the fifties through the seventies. Terra Linda, Marinwood and Lucas Valley in San Rafael, much of central and southern Novato, and the flatter parts of the Ross Valley. From above they read as what they are: repeating plans, simple planes, few penetrations. They are the easiest roofs in the county to lay out and among the most likely to need electrical work first. Composition shingle from this era is often at or past the end of its usable life, which forces a re-roof decision ahead of the array rather than after it.
The Eichler tracts, which are their own category entirely. In this county that means Terra Linda and Lucas Valley around San Rafael, a small group in Strawberry near Mill Valley, and another in Sleepy Hollow near San Anselmo. Low-slope roofs change the mounting system, the flashing detail and the wind uplift calculation. There is no attic to run conduit through and frequently no crawl space either, because the heating is original in-slab radiant, so the routing has to be planned rather than improvised. Exposed post-and-beam ceilings mean any penetration is visible from inside. These are good solar houses when the design respects what they are, and expensive mistakes when it does not. We cover that stock on our Eichler home services page.
Subdivisions from the eighties onward. Larger footprints, hip roofs broken into many small planes, tile in places, and 200-amp services as the norm. The electrical is usually adequate. The roof is the constraint: tile has to be lifted and reset around every mount, small planes waste usable area, and plumbing vents and ridge-mounted equipment tend to land in the middle of the best exposure.
Rural and coastal parcels in west Marin. Out past the ridge the property sets the scope rather than the house: a well pump that has to keep running, a detached barn or shop on its own feed, a long service drop from the road, and often enough open ground that a ground mount beats the roof outright. These parcels also carry a planning layer the rest of the county does not, described in the permit section below.
Robert was very pleasant, professional, and informative. It was nice to receive a call advising that he was on his way, and an email showing me what he looks like. My dog liked him, too!
Kathryn W.
What the battery is asked to carry
Storage is where the era question turns into money, because what the battery has to hold up is set by the building rather than by preference.
The older town-core house. Modest service, gas furnace and gas water heater still in place, small lot. The list of loads worth backing up is short: refrigeration, a handful of lighting circuits, internet, and any medical equipment. A critical loads subpanel usually beats whole-home backup here, and it keeps the scope proportional to a service that was never built for it.
The postwar tract. Whether there is central air conditioning decides everything, because a condenser starting on inverter power is the largest single demand in most of these houses. Inland Marin gets warm enough in late summer that it will be asked to start during exactly the conditions that trigger a planned shutoff. Either the system is sized to start it, a soft starter is added, or the cooling is deliberately left off the backed-up side.
The Eichler. In-slab radiant heating served by a boiler is a modest electrical load but a long-duration one, and the circulating pump is what keeps the house habitable. Where the original system has been replaced with a heat pump, the backup conversation changes shape entirely.
The newer subdivision. Often two HVAC systems, an induction range, a heat pump water heater and a car charging in the garage. Whole-home backup is realistic on this stock because the service can take it, but the useful conversation is about what you are willing to shed, and load management hardware frequently beats simply buying more battery.
The rural west Marin parcel. Water. A submersible well pump's starting current drives inverter selection more than total kilowatt-hours do, and a household that loses water on day one has not really been backed up. Septic pumps, gate operators and livestock water belong on the list ahead of anything decorative.
Roof, service, load, export, in that order
We work Marin projects through those four questions in sequence, because taking them out of order is what produces change orders.
Roof first. Remaining life of the covering, what it is made of, how many layers, and whether the framing can take the mounting. A twenty-five year array over a roof with eight years left is a problem you pay for twice.
Service second. Panel capacity, busbar rating, available breaker space, and whether interconnection lands as a load-side breaker, a busbar-rated arrangement, or a connection ahead of the main. This is the step that most often turns a solar quote into a solar-and-panel quote, and it is the same work covered on our Marin County electrical page.
Load third. What the house consumes, when, and what you plan to add. If a heat pump, a heat pump water heater or a car charger is anywhere in the next five years, the circuits and the panel capacity they need belong in the design now, while an electrician is already at the service. Our Marin County heating and cooling and Marin County plumbing pages cover those sides.
Export last. What the utility credits you for energy sent back, which is now the weakest part of the economics and the reason the first three answers matter so much.
What you get paid for exported energy, and why it changed the design
California's Net Billing Tariff took effect in 2023. In the CPUC's own words, its major difference from the older rules is that "compensation for excess generation exported to the electric grid is applied to a customer's bill at a rate reflecting the value of this generation to the grid," and the earlier net metering tariffs "are closed to new enrollments." Onsite generation "is first used to serve onsite load."
Read that mechanically and the design consequence follows. A kilowatt-hour you use yourself is worth what you would otherwise have paid for it. A kilowatt-hour you export is worth whatever the grid values it at in that hour, which on a sunny afternoon is not much. That is what moved storage from an upgrade to a default, and it is why an array sized purely to zero out an annual bill is usually the wrong array now.
MCE is the community choice energy provider for Marin, supplying the generation side while PG&E continues to handle delivery, billing and interconnection. We confirm which billing arrangement an address sits on before modeling anything, rather than reusing last year's assumptions.
Permits, code and inspection
- State law removes most local discretion. Under Government Code 65850.5, a jurisdiction has to publish "a checklist of all requirements with which small rooftop solar energy systems shall comply to be eligible for expedited review," and an application meeting that checklist "shall be deemed complete." The discretion a counter once had over a rooftop array is largely gone.
- Paper is gone too. The statute obliges every jurisdiction to "allow for electronic submittal of a permit application and associated documentation" and to authorize electronic signatures on the forms.
- SB 379 goes further than streamlining. It "requires most California cities and counties to implement an online, automated permitting platform that verifies code compliance and issues permits in real time" for a residential solar system "no larger than 38.4 kilowatts alternating current," and the California Energy Commission publishes a dashboard of which jurisdictions have implemented it. Corte Madera is one Marin town that has, through an automated platform live since September 2024. Which route a given Marin jurisdiction offers varies, so we confirm it per city rather than promising a turnaround.
- The permit still exists. Streamlining changes how long a counter can sit on an application, not whether you need one.
- Unincorporated parcels file with the Marin County Community Development Agency rather than a city, which is a different queue with its own submittal requirements.
- Coastal-zone parcels in west Marin carry an additional planning layer, because development in the coastal zone can attract a coastal development permit on top of the building permit. That is a question we answer from the parcel before a design is finalized, not after.
- Interconnection and permission to operate run on the utility's clock, separately from the building department's. The gap between a finished installation and a system legally producing is set far more by that sequence than by anything a crew does on the roof.
- We pull the permit, we meet the inspector, and we handle the interconnection application.
Excellent service and products. They installed a full house heat pump/air conditioner and a solar operated whole house generator for power outages. They pay their employees well and treat them well and that is very important to us in this day and age!
Maureen C.
What drives the price of a Marin solar project
We do not publish figures, because a number without the house attached to it is noise. What moves a proposal, roughly in order of how often it decides the total:
Roof covering and condition comes first. Composition shingle is the straightforward case. Tile adds per-mount labor because tiles are lifted, flashed and reset. Wood shake usually means re-roof first. Low-slope Eichler roofs need a mounting and flashing approach designed for them rather than adapted to them.
Plane count, pitch and height are next. A two-story steep roof broken into six small faces takes far longer to lay out, stage and secure than one long single-story plane, and fall protection setup is real time on every face. Framing matters alongside it: rafter size and spacing, sheathing type, and whether anything needs reinforcement, with older skip-sheathed roofs and long-span rural outbuildings the usual culprits.
Service and interconnection is where older Marin housing costs money. Whether the panel can accept the backfeed, whether the busbar rating allows it, whether a main panel replacement or a meter main is required, and where the connection legally lands.
Storage quantity and backup scope follows. A critical loads subpanel is a smaller job than whole-home backup with automatic transfer, and the difference is design rather than hardware alone.
Then distance, shading strategy and access. Ground mounts and detached structures mean trenching, conduit and voltage-drop calculations across the run, which rural parcels feel most. Module-level electronics recover real production on a cut-up or partly shaded roof and cost more than the straight string design an open tract roof can use. And on hillside lots, getting materials and a crew to the roof is a scope item rather than a formality.
We show you the number before work begins, and financing exists so the storage decision is not made purely on one budget year.
Incentives, and the sequencing trap
MCE runs the incentives that reach a Marin address, and its rules are sequencing rules rather than amount rules. MCE's heat pump rebates are open to customers who "own and have lived in their single-family detached homes for at least 12 months in MCE's service area," a qualifying project "must be installed by a participating contractor who will process the rebate application paperwork on your behalf," and "MCE's rebates cannot be applied to a project retroactively."
The condition that catches solar households specifically is a different one. MCE states that "if your home has solar or EV charging, the equipment must have been installed for at least 12 months." So an array that went in last spring can sit between you and a heat pump rebate this autumn, purely on timing. If both are on your list, the order is worth deciding at the start rather than discovering afterwards, and that is one practical argument for a contractor who holds all the licenses instead of coordinating three.
Two other things worth knowing. MCE's EV charging program covers workplaces, multifamily properties of four or more units, and commuter parking lots, so it will not put money toward a charger at a house. Read that narrowly. PG&E runs the residential charger rebate, and its terms say Community Choice Aggregation customers are eligible, so an MCE address is not excluded; MCE's own residential play is MCE Sync, which rewards how you charge rather than what you buy. Sonoma Clean Power programs do not reach a Marin address either.
Program terms move. We confirm what is open when we write your quote.
An array fails quietly
Solar has few moving parts, which is exactly why a neglected system underperforms for years without anyone noticing. Monitoring is the maintenance. If nobody reads the production data, a failed optimizer or a tripped string simply becomes a higher bill.
Marin adds two specific soiling patterns. Near the water, salt-laden marine air works on hardware and leaves a film that reduces output and starts corrosion on fasteners and enclosures. Under canopy, pollen plus redwood, oak and bay debris accumulate, and in a wooded neighborhood a shading change from ordinary tree growth shows up as a slow seasonal decline long before anything looks wrong from the ground. The first serious rain does much of the cleaning, though not all of it.
The owner's checklist is short: watch the production data, keep battery firmware current with the warranty registered, and test the backup once or twice a year, because a battery that has never been asked to discharge is not evidence that it will. We install with the long run in mind, critter guard fitted at the outset and flashing at every penetration, and if the roof is anywhere near replacement age we say so before the array goes on, since installing on a new roof is much cheaper than working around an old one.
Where we work across the county
Everything is dispatched from our Petaluma headquarters. We have no office in any Marin city and we do not pretend otherwise; what we have is a short run down the highway and a long history in these towns.
City solar pages: San Rafael, Novato, Mill Valley, Sausalito, Corte Madera and Belvedere. Beyond those, we work the Ross Valley through Larkspur, Kentfield, Greenbrae, Ross, San Anselmo and Fairfax, the Tiburon peninsula, Marin City and Strawberry, the San Geronimo Valley communities, and out through west Marin to Nicasio, Point Reyes Station, Inverness, Olema, Bolinas, Stinson Beach, Muir Beach, Marshall, Tomales and Dillon Beach. The Marin County service overview lists every community we cover.
How to choose a solar contractor here
Ask who holds the license and who will be on your roof, because in this trade the two are frequently different companies.
Ask whether the electrical scope is in house or subcontracted, since the service work is where the surprises live on Marin housing.
Ask who pulls the permit, who files the interconnection, and who meets the inspector.
Ask whether the production model came from a shade study of your specific roof or a satellite estimate of your address, which in a wooded county is the difference between a forecast and a guess.
Ask what the proposal assumes about exported energy, because a model still running on retail-rate export credits is describing a tariff that no longer exists for new systems.
If you own an Eichler, ask what mounting and flashing system is proposed for a low-slope roof and how conduit will be routed without an attic.
If a heat pump is anywhere in your plans, ask how the MCE timing rules affect the order of the two projects.
Then ask who answers the phone in year six.
We hold C-10 electrical, C-20 HVAC and C-36 plumbing classifications, and we are Diamond Certified with a BBB A+ Rating. A family business here since 1932 is a reasonable answer to that last question, and our customer reviews are worth reading first.
What North Bay homeowners say
Two notes from customers, unedited.
Book solar work in Marin County
Ready to find out what your roof and your service will support? Book online and we will put a site visit on the calendar. We assess the roof, open the panel, model the shading on your specific planes, and walk through the options with the current rules attached, including what it would take to keep the house running when the grid is off. Ongaro & Sons also covers electrical, plumbing and heating and cooling throughout the county. Browse the main solar page, review the Marin County service area, see the maintenance program, check financing, or read what customers say.
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Ongaro & Sons is your trusted heating, cooling, plumbing, electrical, and solar expert, specializing in reliable maintenance and repair services that keep your home running efficiently year-round.
Our certified technicians deliver unmatched expertise with fast, friendly service across Marin, Sonoma and Napa County. From HVAC tune-ups to plumbing repairs and electrical upgrades or solar solutions, we focus on energy-efficient performance and long-term comfort. Count on us to maintain the systems that power your home and keep your environment just the way you like it.
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Read MoreSolar in Marin County: common questions
Who is the best solar company in Marin County?
Ongaro & Sons. We have been a family business working in this county since 1932, we are Diamond Certified, we hold a C-10 electrical license so the service and interconnection work stays in house, and we carry 2,726 Google reviews averaging 4.8 stars. We pull permits in every jurisdiction here, from the individual city counters to the county, and we design around the house rather than around a template.
Will my rooftop solar keep the lights on during a Public Safety Power Shutoff?
Not on its own. Grid-tied inverters are built to stop producing when the utility grid is de-energized, so a system without storage goes dark along with the neighborhood. Backup requires a battery plus transfer equipment that isolates your house from the grid. Given that planned shutoffs here can run for days rather than minutes, most Marin homeowners want that capability designed in from the start.
Does solar still make financial sense under the current export rules?
For a lot of houses, yes, though the shape of the answer changed. Since the Net Billing Tariff replaced retail-rate net metering for new applicants, energy you consume on site is worth considerably more than energy you push back to the grid. That favors right-sizing the array to real household usage and adding storage, rather than building the largest system the roof will hold.
Who issues my solar permit in Marin?
It depends on which side of a city limit your parcel sits. Eleven cities and towns each run their own building department and submittal system, and everything outside those limits goes through the county. Because several communities with a city mailing address are unincorporated, we verify the authority by parcel rather than by address before filing anything.
Does tree cover rule out solar here?
Not automatically, though it has to be measured rather than assumed. Canopy and hillside shading create patterns that vary by season and by hour, and two neighbors can get very different results. Module-level electronics let partially shaded strings keep producing instead of dragging the whole array down. Where the canopy is dense and permanent, an open area on the property sometimes outperforms anything the roof can do.
Can you put solar on an Eichler?
Yes, and it is a different job from a conventional roof. Low-slope construction changes the mounting system, the flashing detail and the uplift calculation. With no attic and often no crawl space, conduit routing has to be designed rather than improvised, and exposed post-and-beam ceilings mean any penetration is visible from inside. Done with that in mind, these houses take solar well.
Will I need an electrical panel upgrade before solar?
Sometimes, and it depends on the busbar rating and available space more than on the amperage printed on the door. Older services in the county's town cores frequently cannot accept a backfeed breaker as built. Legal alternatives exist, including connecting ahead of the main, but they have to be evaluated at the panel. We do that assessment before quoting rather than after.
Should the roof be replaced before the panels go up?
If the covering has fewer than about ten years left, replacing first is usually the cheaper path. Modules outlast most roofing, so installing over a tired roof buys a removal and reinstall later that costs real money and gains you nothing. We assess remaining life, layer count and framing during the site visit and tell you which sequence saves money.
Do I need a battery, or can I add one later?
Adding later is possible, though rarely as clean as doing it together. Retrofitting storage often means revisiting the interconnection, adding a subpanel or transfer equipment, and sometimes replacing an inverter never designed to pair with a battery. If storage is even a maybe, we design the electrical for it up front so the second phase is an addition rather than a rework.
What incentives apply to a Marin solar project?
MCE is the community choice provider here and runs electrification rebates with strict conditions: a participating contractor has to file the paperwork, the application cannot be made retroactively, and where a home already has solar or EV charging that equipment must have been in place at least twelve months. Sonoma Clean Power offers do not reach Marin. We verify what is live at quote time.
Does a coastal parcel in west Marin need extra approvals?
It can. Development in the coastal zone is governed by the county's Local Coastal Program, and a coastal development permit may be required depending on the work and the location, with specific exclusions that apply in some areas. That question is answered at the start of design, because finding out afterward changes the schedule rather than the design.
Why use a full-trade contractor instead of a solar-only installer?
Because on most Marin homes solar is not a standalone job. It touches the electrical service, it interacts with heating and water heating decisions, and it is frequently sized around loads you have not added yet. Running electrical, HVAC and plumbing under one roof means a panel upgrade, a heat pump and an array can be sequenced as one project, including around the rebate timing rules, instead of three companies pointing at each other.
How much upkeep does a solar system really need?
Less than most equipment, but not zero. Watch the production data, because a partial failure shows up as a quiet shortfall rather than an obvious fault. Expect the inverter to need attention before the modules do. Rinse off accumulated salt film, pollen or tree debris when the site warrants it, keep rodents from nesting underneath, and inspect roof penetrations periodically.