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 Battery Storage & Backup Across San Anselmo
Solar battery backup in San Anselmo typically runs $14,000 to $22,000 installed for a single battery system, with most installs completed in one to two days once permits clear. If you live in the Ross Valley and your panels already produce more than you use in summer but you’re still paying full retail rates every winter, a battery is usually the missing piece. We’re Gus’s Solar, and we’ve been working on San Anselmo homes long enough to know exactly which rooflines, panels, and tree canopies change the math on storage. Call (877) 550-6892 and bring us your bill. We’ll show you the year-25 numbers, not a brochure figure.
Why Gus’s Solar Is San Anselmo’s Preferred Solar Battery Storage & Backup Company
San Anselmo isn’t San Rafael. The same solar array that performs beautifully on a flat lot in Terra Linda can lose 40% of its output half a mile up a shaded canyon off Butterfield Road. That’s not a sales pitch. It’s what we see when we pull production data from systems installed by out-of-town crews who never walked the property before quoting.
Gus Petrakis put his name on this company in 2011, and he still answers his own phone. When a San Anselmo customer calls about a battery that isn’t cycling correctly after a PG&E outage, the call isn’t routed to a ticketing queue. Gus picks up, checks the monitoring portal, and sends his own crew. The same crew that did the install. Background-checked, uniformed, and trained on the exact hardware on your wall. We don’t hand work to subs.
Every job carries the 90-Day Done Right Promise in writing. If something isn’t right, one call brings Gus back. And the price we quote is the price charged. Take two weeks to think about it. The number won’t change. If a salesman needs an answer tonight, the answer is no. That’s how we’ve operated for over 29 years in local communities, and it’s why San Anselmo homeowners keep our number saved.
We also honor a Senior and Veteran 10% discount that never expires, and we’re glad to offer a free second opinion on any written estimate from another installer. Bring us a bill, we’ll bring you the math.
Our Solar Battery Storage & Backup Services in San Anselmo
Tesla Powerwall Installation
A Tesla Powerwall 3 installed in San Anselmo typically runs $13,500 to $17,500 before any electrical upgrades, and it’s the most common choice for whole-home backup on homes in the 94960 and 94979 zip codes. On an older home near Creek Park, the limiting factor is rarely the battery itself. It’s the main panel, which we’ll get to below. We install Powerwalls with the Gateway configured for whole-home or partial-home backup, depending on your load profile and panel capacity.

Enphase IQ Battery Installation
Enphase IQ Battery systems run roughly $12,000 to $16,000 for a 10 kWh setup in San Anselmo, and they pair naturally with existing Enphase microinverter arrays. If your system already has an Enphase combiner box, adding storage often avoids a full panel swap, which matters on Craftsman bungalows where the meter can is recessed into a lath-and-plaster wall. We size IQ batteries to your actual winter usage, not your summer peak.

Whole-Home Backup Power
Whole-home backup in San Anselmo means sizing batteries to carry your December and January loads, when the south ridgeline cuts production below what net metering credits can offset. For most homes in the Ross Valley that’s two to three batteries, landing between $24,000 and $35,000. We’ll show you actual wattage data from your meter before you spend a dollar. If one battery will cover your essential circuits and two will carry the whole house, we’ll tell you both numbers and let you decide.

Battery Retrofit for Existing Solar
Retrofitting a battery onto an existing San Anselmo solar system is more nuanced than new construction. We recently worked on a 1920s Craftsman bungalow off Bolinas Avenue where the homeowner had a six-year-old SunPower array installed by a national outfit. A heritage oak blocked the southwest azimuth, killing winter kWh offset. We retrofitted an Enphase IQ Battery, coordinated a 100-amp to 200-amp panel upgrade, and rewired the interconnection to a whole-home backup configuration so she could ride through the PG&E Public Safety Power Shutoffs that regularly hit the Ross Valley. That job required a tree report, a panel upgrade, and a custom interconnection plan. The town’s permit desk keeps a dedicated checklist for exactly this situation.
Retrofit pricing in San Anselmo lands between $11,000 and $19,000, depending on whether your existing inverter architecture supports AC coupling or requires a full DC reconfiguration. See our Solar Battery Storage & Backup page for a full breakdown of what retrofits involve.

Time-of-Use & NEM 3.0 Optimization
If you’re on NEM 3.0, your export credits are worth a fraction of what they were under NEM 2.0. A battery changes the economics entirely. Instead of selling midday solar for pennies and buying back at peak rates, you store it and use it. In San Anselmo, where winter production drops below 50% of nameplate due to ridgeline shading, a battery is often the only way to bank usable power from December through February. We’ll pull your actual PG&E interval data and model the payback on a Qcells or REC array paired with storage. No generic spreadsheet. Your bill, your tariff, your roof.

What happens when you call
- 1
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 San Anselmo
We install and service Tesla, Enphase, SolarEdge, SunPower, Panasonic, and FranklinWH systems, which covers nearly every battery on a San Anselmo roof today. If you have a SunPower array and want to know whether a Tesla Powerwall can integrate, the answer is usually yes with the right gateway configuration. If you have a Qcells or REC array that an out-of-state company orphaned, we’ll take over monitoring and maintenance. Our team keeps common firmware versions and gateway parts stocked locally, so we’re not waiting on a shipment from Texas when your system throws a fault.
Common Solar Battery Storage & Backup Problems We See in San Anselmo Homes
- Winter shading from the south ridgeline slashes production below what net metering credits can offset. Homes on north-facing slopes or tucked against the hills south of Sir Francis Drake Boulevard see solar output collapse in December and January. Without a battery, the true-up statement leaves owners paying full retail for half the year, often more than they paid before going solar.
- Aging 60 to 100 amp panels on pre-1940s homes can’t carry a battery backup circuit. Most Victorian-era and Craftsman homes in San Anselmo’s older neighborhoods still run on panels that were sized for gas appliances. Adding a battery to a 100-amp main risks tripping the breaker when the grid drops. We coordinate panel upgrades as part of the battery install, not as a surprise change order.
- Steep 7:12 or steeper roof pitches on multi-plane Victorians limit where an inverter can be mounted. Adding a battery often means relocating the existing microinverter gateway to a code-compliant spot. On older homes along areas like Creek Road, that can mean running conduit through a crawlspace rather than a clean exterior mount, which adds labor but keeps the install inspection-ready.
- Heritage oak and redwood trees block production in ways satellite imagery misses. Marin County tree ordinances protect mature canopy, and trimming permits are routinely denied or limited. A property that looks viable from aerial photos can be functionally solar-dead on the southwest azimuth. A battery can’t create sunlight, but it can store what little you get. We’ll tell you honestly if a battery is worth it on your specific lot.
Pricing for Solar Battery Storage & Backup in San Anselmo, CA
A single battery install in San Anselmo runs $12,000 to $17,500. Two-battery whole-home systems land between $24,000 and $32,000. Retrofit jobs, where we’re adding storage to an existing array and possibly upgrading the main panel, run $11,000 to $19,000 depending on whether we’re working with AC-coupled Enphase hardware or a DC-coupled SolarEdge setup. The biggest cost swings come from electrical panel upgrades, which add $2,500 to $5,000 when your home still runs on a 100-amp service. We quote the year-25 output, not the day-one brochure number. Estimates are free. Call (877) 550-6892 and we’ll come out to San Anselmo, walk the roof, check the panel, and give you a written number you can take two weeks to consider.
We Also Serve Cities Near San Anselmo
We work throughout Marin County, including Fairfax, Kentfield, San Rafael, and Larkspur. If you’re in one of those towns, you’ll get the same local crew and the same upfront pricing. You can see more on our San Anselmo service page or call us directly.
Serving San Anselmo, CA - Our Local Coverage Area
We’re based in the San Anselmo 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 Battery Storage & Backup in San Anselmo
An east-west roofline with heavy winter shading needs a larger battery than a south-facing roof with clear exposure, because you’ll be storing less total energy and drawing from the battery earlier in the evening on NEM 3.0 rates. On a shaded hillside home in San Anselmo, we usually size batteries at 1.3 to 1.5 times the daily winter evening load, rather than the 1.0 ratio that works on flat south-facing roofs in San Rafael. Call (877) 550-6892 and we’ll model your actual production curve, not a generic roof profile.
Usually no, not without a main panel upgrade. A 100-amp panel cannot support the backup circuits a Powerwall requires under Marin County’s electrical code, so the panel swap becomes part of the project. In San Anselmo’s older housing stock, that $2,500 to $5,000 upgrade is one of the most common line items on battery retrofits. We’ll tell you in the first visit whether your panel is a constraint, and we’ll include it in the written quote, not spring it later. Estimates are free.
Yes, if you size it for whole-home backup, which in San Anselmo typically means two to three batteries. A single battery will carry essential circuits like the fridge, well pump, modem, and a few lights for 12 to 24 hours. Two to three batteries will run the whole house, including electric stoves and HVAC, through a multi-day PSPS event. We’ll show you actual wattage data from your meter and let you decide where the line sits. Call (877) 550-6892 for an exact quote. Estimates are free.
The south ridgeline of the Ross Valley blocks low-angle winter sun from reaching south-facing and east-west roofs from December through February, even though San Anselmo burns off the marine layer faster than coastal Marin. When the sun angle drops below 30 degrees, the hills south of town cast shadows that standard solar production models don’t fully account for. A battery stores what production you do get, so you’re not buying back at retail rates during those shaded months. Bring us your bill and we’ll show you the real math. Call (877) 550-6892.
Sometimes, but the math is tighter than on NEM 3.0. On NEM 2.0 you already get near-retail credit for exported energy, so a battery’s main value is outage protection, not bill savings. If you don’t lose power often and your winter true-up is acceptable, a battery may not pencil out for you, and we’ll tell you that. If you’re in a PSPS-prone canyon off Butterfield Road or near the open space edges, backup power has more value. Call (877) 550-6892 and we’ll run the numbers honestly, even if the answer is that you don’t need one yet.
Written by Gus Petrakis, Owner at Gus’s Solar, serving San Anselmo and Marin County since 2011.






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