The Complete Google Sunroof Guide (2026): How to Get a Solar Estimate Without Sharing Your Contact Info Using Project Sunroof & AI Tools
- 3 days ago
- 19 min read
A homeowner in Torrance called me two summers ago, frustrated. She'd gone online to look up whether solar made sense for her house, entered her address into what looked like a solar calculator, and within four minutes had three calls from different companies she'd never heard of. She hadn't even finished reading the results.
"I just wanted a number," she said. "I didn't want to talk to anyone yet."
That story is more common than the solar industry would like to admit. A lot of what looks like a "free solar calculator" online is actually a lead generation form — its real job isn't to give you information, it's to sell your contact details to installers who pay $30 to $80 per lead. The estimate you get is often secondary to that transaction.
Google Project Sunroof is different.
It's one of the few tools built specifically to give homeowners real roof-level solar data — usable sunlight hours, estimated system size, projected savings — without requiring a phone number, email address, or any personal contact information at all.
But it has real limitations in 2026 that most guides don't tell you about honestly. Its cost and savings data hasn't been meaningfully updated since 2018, it doesn't account for California's NEM 3.0, and it can't calculate your actual payback period with any precision.
That's where a three-tool workflow comes in: Project Sunroof for roof data → NREL PVWatts for production accuracy → AI tools for personalized calculations.
Used in sequence, this is the most reliable way to get a Google Project Sunroof solar estimate with no contact info — three free tools that give you genuinely useful numbers without ever sharing your name, phone number, or email with a sales team.
Here's exactly how to do it.
Quick Answer:
You can get a private, accurate solar estimate in 2026 using three free tools — no contact info required.
Step 1: Use Google Project Sunroof (sunroof.withgoogle.com) to get your roof's usable area and annual sun hours.
Step 2: Run those numbers through NREL PVWatts (pvwatts.nrel.gov) for accurate production data.
Step 3: Feed both into an AI tool (ChatGPT or Claude) with your utility bill to calculate system size, savings, and payback period specific to your California utility and NEM status.
Total time: about 20–30 minutes.
Table of Contents
Why Most "Free Solar Calculators" Are Actually Lead Generation Forms
What Google Project Sunroof Actually Does — And What It Doesn't
How to Use Project Sunroof: Step-by-Step (2026)
What Project Sunroof Gets Right — And Where Its Numbers Go Wrong
Step 2: NREL PVWatts — The Tool That Fixes Project Sunroof's Biggest Gap
Step 3: How to Use AI Tools to Build Your Personalized Solar Estimate
The Complete Three-Tool Workflow: From Zero to a Real Solar Estimate
How to Use Your Private Estimate When You're Ready to Talk to Installers
Scenarios: What This Looks Like for Three Different California Homes
FAQ
Conclusion
Related Posts
Why Most "Free Solar Calculators" Are Actually Lead Generation Forms
Before getting into how Project Sunroof works, it's worth understanding the ecosystem it exists in — because knowing the difference between an educational tool and a lead-gen form is the single most important thing you can do before typing your address into anything solar-related.
Here's how the solar lead generation business works. When you enter your address and click "Get My Free Estimate" on most solar websites, that information — your name, address, phone number, email — gets packaged as a "lead" and sold to one or more local installers. The going rate for a residential solar lead in California ranges from roughly $30 to $80, depending on the market. Some platforms sell the same lead to multiple companies simultaneously. That's why, as the Torrance homeowner discovered, four minutes after entering your information you're getting calls from three different companies.
This isn't inherently dishonest — some of those installers are legitimate, and eventually you'll need to talk to one. But the timing matters. Getting calls before you've done any of your own research puts you at a significant disadvantage. You don't know what system size makes sense, what the fair price range is, or what questions to ask. A pushy salesperson in that moment has a real advantage.
The tools worth using at the research stage are the ones that have no financial incentive to capture your contact information. That means government or nonprofit tools — NREL PVWatts, Project Sunroof, the CPUC's rate calculators — and AI tools you interact with directly.
The tell: if a calculator asks for your phone number before showing you results, it's a lead form. If it shows you results first and only optionally asks for contact information to "connect you with installers," that's better but still worth being cautious about. The tools in this guide require zero contact information at any step.
For more on how to recognize solar sales tactics and red flags, see Solar Scams in California (2026): How to Spot Red Flags, Avoid Fake Offers, and Protect Your Home.
What Google Project Sunroof Actually Does — And Why It's the Right Starting Point for a No-Contact Solar Estimate
Google Project Sunroof (sunroof.withgoogle.com) was built in 2015 by Carl Elkin, a Google engineer in Cambridge, Massachusetts, and has since expanded to cover more than 43 million rooftops across the United States. The tool's stated mission is simple: "Mapping the planet's solar potential, one roof at a time."
What makes Project Sunroof genuinely useful is the data layer underneath it. When you enter an address, the tool pulls from three sources:
Google Earth aerial imagery creates a 3D model of your specific roof — its dimensions, pitch angle, and orientation (which direction it faces). South and southwest-facing roofs capture the most sun in the Northern Hemisphere; Project Sunroof maps this automatically for your address.
Shadow modeling uses that 3D geometry to calculate how nearby trees, chimneys, neighboring buildings, and other obstructions shade your roof at different times of day throughout the year. This is more sophisticated than most people realize — it's tracking the sun's arc across the sky for your specific latitude and longitude across all 365 days.
Historical weather data layers in cloud cover patterns, regional solar irradiance averages, and temperature data to give you a localized estimate of how much usable sunlight your roof receives per year, measured in peak sun hours.
The output is your roof's annual usable sunlight hours and the recommended solar panel area — two numbers that are genuinely difficult to calculate on your own and that Project Sunroof gets reasonably right.
What Project Sunroof does not do well:
The tool's cost estimates and savings projections are based on data that was last meaningfully updated around 2018. That's a significant problem in 2026 because:
Solar panel prices have dropped substantially since 2018. The current California average installed cost is approximately $2.41 per watt before incentives (EnergySage, April 2026). Project Sunroof's cost estimates can be off by $10,000 or more in either direction for the same system.
The federal 30% residential solar tax credit (Section 25D) expired December 31, 2025. Project Sunroof's savings estimates may still factor in that credit, which no longer applies to homeowners who purchase systems directly in 2026.
NEM 3.0 went into effect in April 2023 and cut export compensation by roughly 75% for new California solar installations. Project Sunroof's savings model does not reflect NEM 3.0 economics at all, which means its projected savings for California homes can be significantly overstated for anyone installing today.
The bottom line on Project Sunroof: use it for roof data, not for financial projections. The sun hours and panel area it gives you are solid. The dollar figures are not reliable in 2026.
How to Use Google Project Sunroof for a Solar Estimate With No Contact Info: Step-by-Step (2026)
This is the practical walkthrough. No account required, no email, no phone number.
Step 1: Go to sunroof.withgoogle.com
The site loads a map interface. You'll see a search bar at the top. Enter your street address — just the address, nothing else. The site does not ask for any personal information.
Step 2: Review the aerial view of your roof
Once you enter your address, Project Sunroof displays a satellite view of your home with a color overlay. Areas shown in yellow or orange represent the portions of your roof receiving the most direct sunlight. Darker areas indicate shading from trees, chimneys, or roof angles that receive less sun.
Spend a moment verifying this matches what you know about your home. If there's a large tree on the south side of your house, it should show up as a shaded area. If the imagery looks several years old (you can often tell by landscaping changes), note that — it may affect the shading analysis.
Step 3: Record these three numbers
After the map loads, Project Sunroof shows an estimate panel. Write down:
Annual usable sunlight hours — typically 1,300–1,500 hours/year across most of California
Recommended installation size — shown in kW, this is the system size Project Sunroof suggests based on your roof area
Roof area available for solar — shown in square feet; useful for cross-checking installer proposals later
Step 4: Adjust the monthly bill slider
The tool has a slider that lets you input your average monthly electricity bill. Move it to match your actual bill. This changes the recommended system size but does not change the underlying sun hours data — that's based purely on your address. The bill input does affect the financial projections shown, but as discussed, those projections are not reliable for 2026 California. Record the adjusted system size recommendation — that's the number you'll take to PVWatts next.
Step 5: Ignore the cost and savings estimates
The tool will show you an estimated cost range and projected 20-year savings. Do not use these numbers for any planning purposes. They are based on pre-NEM 3.0 economics and pre-2026 pricing. They are starting points for curiosity, not for financial decisions.
What you leave with: your roof's annual sun hours, usable area, and a rough system size recommendation. These three data points are the useful output. Everything else requires the next two steps to make accurate.
What Project Sunroof Gets Right — And Where Its Numbers Go Wrong
It helps to see this as a simple table before moving to the next tool.
Data Point | Project Sunroof Accuracy | Notes |
Roof orientation (N/S/E/W) | Reliable | Based on Google Earth 3D imagery |
Annual peak sun hours | Reliable | Historical weather data, well-validated |
Shading from trees/structures | Mostly reliable | Imagery age can affect accuracy |
Recommended system size (kW) | Approximate | Good starting point, verify with PVWatts |
Installed cost estimate | Not reliable | Based on ~2018 data; off by $5,000–$15,000+ |
Monthly/annual savings | Not reliable | Doesn't account for NEM 3.0 or 2026 CA rates |
Federal tax credit calculation | Outdated | 30% ITC expired Dec 31, 2025 for homeowners |
Payback period estimate | Not reliable | Combination of above errors |
The rule of thumb: anything that requires a dollar sign in the output, go elsewhere in 2026. The physical data — sun hours, roof area, shading — is genuinely solid.
For a breakdown of what California solar actually costs in 2026 without the federal tax credit, see Is Solar Still Worth It in California 2026 Without the Federal Tax Credit?.
Step 2: NREL PVWatts — The Tool That Fixes Project Sunroof's Biggest Gap
NREL PVWatts (pvwatts.nrel.gov) is the gold standard for solar production estimation in the United States. Built and maintained by the National Renewable Energy Laboratory — the U.S. Department of Energy's primary renewable energy research facility — it uses 30+ years of solar radiation data to estimate how much electricity a system at a specific location will produce in a given year.
Unlike Project Sunroof, PVWatts requires no contact information of any kind. You enter a location and system parameters, and it returns a detailed monthly and annual production estimate. No account. No email. Nothing.
What PVWatts gives you that Project Sunroof doesn't: accurate kWh production estimates, broken down by month. This is the number you actually need — not "peak sun hours" or "recommended kW," but "how many kilowatt-hours will this system produce in January, in July, across the full year." That's what determines your actual bill savings.
How to use PVWatts for a California home:
Go to pvwatts.nrel.gov. Enter your address or zip code — again, no personal information required. The tool auto-populates your location's solar irradiance data.
Under "System Info," enter the DC system size in kW — use the number from Project Sunroof as your starting point. Leave the module type as "Standard" unless you know your installer will use premium panels. For array type, select "Fixed (roof mount)."
For tilt angle, enter your roof pitch. A standard California residential roof is typically 18–26 degrees. If you're unsure, 20 degrees is a reasonable default.
For azimuth (the direction your roof faces), use 180 for due south, 225 for southwest, 270 for west. South and southwest face optimally in California.
Leave the system losses at the default 14% for now. This accounts for wiring losses, inverter efficiency, soiling, and other real-world factors.
Reading the results: PVWatts shows you monthly AC energy output in kWh and an annual total. For a 7 kW system in Los Angeles, a south-facing roof will typically produce approximately 10,500–11,500 kWh/year. For the same system in San Francisco, expect roughly 9,500–10,500 kWh/year due to lower irradiance and more cloud cover.
Take note of the monthly breakdown. Summer months will show significantly higher production than winter. This matters for California TOU (time-of-use) rate planning under NEM 3.0.
What PVWatts doesn't do: it doesn't calculate your bill savings, payback period, or compare financing options. For those calculations, you need the third tool.
If you want to see how PVWatts compares against other free calculators before committing to a system size, see I Tested 3 Free Solar Calculators in California (2026) — Here's What They Actually Got Right.
For guidance on how to read your production estimates against California utility rates, see Why Bills Keep Rising and How Solar Can Help (California Electricity Rates 2026).
Step 3: How to Use AI Tools to Complete Your Google Project Sunroof Solar Estimate (No Contact Info Needed)
This is where the workflow gets genuinely powerful. Once you have roof data from Project Sunroof and production data from PVWatts, you have everything needed to complete a full Google Project Sunroof solar estimate with no contact info — an AI tool (ChatGPT or Claude) combines that with your actual utility bill to calculate system size, estimated savings, and payback period with a level of personalization that no generic calculator can match.
Why AI tools work for this: they understand context. You can tell Claude or ChatGPT "I'm on SCE's TOU-D-PRIME rate, my average bill is $280/month, I'm considering NEM 3.0, and PVWatts says a 7 kW system will produce 10,800 kWh/year at my address" — and the AI can walk through the actual math with those specific inputs, explain each step, and answer follow-up questions.
What AI tools cannot do: they cannot see your actual roof, pull real-time utility rate data, or replace a licensed solar installer's site assessment. Use them for calculation and planning, not for final system design.
How to use AI tools for a Google Project Sunroof solar estimate without contact info:
Here's a prompt template you can copy directly into ChatGPT or Claude:
"I'm researching solar for my home in [ city ], California. I want to understand my options before talking to any installers. Here's what I have:
From Google Project Sunroof: [ X ] annual peak sun hours, [ X ] sq ft usable roof area, recommended system size [ X ] kW
From NREL PVWatts: annual production estimate [ X ] kWh/year for a [ X ] kW system, south-facing, [ X ]-degree tilt
My utility is [ PG&E / SCE / SDG&E / LADWP ] on a [ rate plan ] plan. My average monthly electricity bill is $[ X ].
I would be installing new solar in 2026, so I'd be on NEM 3.0, not NEM 2.0. The federal 30% tax credit no longer applies to homeowners in 2026.
Please calculate:
(1) How much of my bill could solar offset?
(2) What would my estimated annual savings be under NEM 3.0?
(3) At a cost of $2.41/watt installed (California 2026 average), what would this system cost and what's the approximate payback period?
(4) Would adding a battery change the payback period significantly?"
The AI will work through each calculation step by step. You can ask follow-up questions: "What if I install a 9 kW system instead?" or "How does SDG&E's EV-TOU-5 rate affect the self-consumption math?" The conversation stays private — no data goes to solar companies.
One important caveat: AI tools work from training data that may not reflect the very latest utility rate changes. For California-specific rate accuracy, cross-reference any AI output with your current utility bill and the rate schedules published at pge.com, sce.com, or sdge.com. The AI's calculation logic is sound; the input rates should be verified.
For the exact current California utility rates to use in your AI prompt, see Why Bills Keep Rising and How Solar Can Help (California Electricity Rates 2026).
The Complete Three-Tool Workflow: From Zero to a Real Solar Estimate
Here's the full sequence in one place, with the specific data to record at each step.
Step 1 — Google Project Sunroof (15 minutes)
Go to: sunroof.withgoogle.com
Enter your address (no contact info required)
Record: annual peak sun hours, usable roof area (sq ft), recommended system size (kW)
Set the monthly bill slider to your actual average bill
Ignore all cost and savings dollar figures
Step 2 — NREL PVWatts (10 minutes)
Go to: pvwatts.nrel.gov
Enter your address or zip code
Input: system size from Step 1, roof tilt, roof direction (azimuth)
Leave system losses at 14% default
Record: annual kWh production, monthly production breakdown
Step 3 — AI Tool (20–30 minutes)
Go to: chatgpt.com or claude.ai (free accounts work)
Use the prompt template from the previous section
Input: sun hours and roof area from Step 1, annual kWh from Step 2, your utility, rate plan, and average bill
Ask for: bill offset percentage, annual savings under NEM 3.0, system cost at $2.41/watt, payback period, battery impact
What you have at the end: A private, personalized solar estimate that includes your roof's actual solar potential, a production number validated against government weather data, and savings/payback calculations specific to your utility and rate plan. Total time: approximately 45 minutes. Contact information shared: zero.
How to Use Your Private Estimate When You're Ready to Talk to Installers
The point of doing this research privately isn't to avoid installers forever — it's to approach that conversation from an informed position rather than a reactive one.
When you're ready to get actual quotes, here's how the homework you've done changes the dynamic:
You know your system size.
When an installer says "we'd recommend a 9 kW system for your home," you can ask why — your PVWatts estimate suggested 7 kW covers your usage. Either they know something you don't (shading, future load growth, EV charging) or they're upsizing the system for margin. You can have that conversation productively.
You know the fair price range.
The California average installed cost in 2026 is approximately $2.41/watt before incentives (EnergySage, April 2026). For a 7 kW system, that's roughly $16,870 before any state or utility incentives. If a quote comes in at $24,000 for the same system, you know to ask what's in that number — premium panels? Extensive rerouting? Or just margin?
You know your real payback range.
Under NEM 3.0 without a battery, a well-sized California system typically has a payback period of 9–13 years. With a battery and smart TOU usage, that can compress to 6–9 years. If an installer promises "payback in 4 years," you know that number requires extraordinary assumptions — ask them to show the math.
You haven't given your contact info to lead generation platforms.
This means the installers you do talk to are ones you've chosen to contact, not ones who've purchased your information. That changes the entire sales dynamic.
For guidance on evaluating installer quotes, see 7 Hidden Solar Installation Costs in California (2026): What Your Quote Isn't Telling You and How to Get a Solar Estimate Without Sharing Your Contact Info.
Scenarios: What This Looks Like for Three Different California Homes
Scenario 1 — SCE customer in Pasadena, $220/month average bill
Project Sunroof output: 1,480 annual sun hours, 380 sq ft usable roof area, recommended 6.5 kW system. PVWatts output for 6.5 kW system, south-facing, 22-degree tilt: approximately 9,750 kWh/year.
AI calculation (using SCE TOU-D-PRIME rates, NEM 3.0, no battery): The home uses approximately 8,400 kWh/year based on the $220/month bill. A 6.5 kW system producing 9,750 kWh covers 100%+ of annual consumption, but under NEM 3.0, the ~1,350 kWh exported earns only ~$95/year in credits (at ~$0.07/kWh avoided cost). Annual savings estimate: approximately $1,680 from self-consumption offset, plus $95 export credit = ~$1,775/year. Installed cost at $2.41/watt: ~$15,665. Estimated payback: approximately 8.8 years without battery, ~6.5 years with a battery optimizing peak-hour discharge.
Scenario 2 — PG&E customer in Fresno, $310/month average bill
Project Sunroof output: 1,510 annual sun hours, 520 sq ft usable roof area, recommended 9 kW system. PVWatts output: approximately 13,900 kWh/year.
AI calculation (PG&E E-ELEC rate, NEM 3.0, no battery): Home uses approximately 11,900 kWh/year. System oversizes slightly, exporting ~2,000 kWh at low avoided-cost rates. Annual savings from self-consumption: approximately $2,975. Export credit: ~$140. Total annual savings: ~$3,115. Installed cost: ~$21,690. Payback: approximately 7 years — better than average due to Fresno's high irradiance and PG&E's rising rates. Battery addition could push payback to ~5.5 years.
Scenario 3 — SDG&E customer in San Diego, $380/month average bill
Project Sunroof output: 1,490 annual sun hours, 410 sq ft usable roof area, recommended 8 kW system. PVWatts output: approximately 12,200 kWh/year.
AI calculation (SDG&E EV-TOU-5 rate, NEM 3.0): SDG&E has the highest residential rates in the state — super off-peak as low as ~$0.12/kWh, but peak hours hitting ~$0.80/kWh in summer. Under NEM 3.0, self-consumption is extraordinarily valuable here. Battery storage essentially mandatory to capture full value. Annual savings with solar + battery: approximately $3,900–$4,400. Installed cost solar only: ~$19,280. Add battery (~$8,000–$12,000 after SGIP rebate): total ~$27,000–$31,000. Payback with battery and SGIP: approximately 6.5–7.5 years — SDG&E's extreme rate spread makes battery ROI compelling here specifically.
For the SGIP rebate details that affect Scenario 3, see SGIP Battery Rebate + NEM 3.0 in California: The 2026 Guide to Stacking Incentives and Cutting Your Payback Period.
FAQ: Google Project Sunroof Solar Estimate Without Contact Info (2026)
Q: Does Google Project Sunroof sell my information to solar companies?
A: No — and this is the key distinction between Project Sunroof and most solar lead generation sites. Google's tool is designed to be educational. It does display a list of local installers at the bottom of results, but clicking on those is optional and that interaction is separate from the roof analysis itself. Simply entering your address and viewing your roof's solar data does not trigger any lead sale. Google stopped formally selling leads to installer partners after an early phase and now operates purely as an information tool.
Q: How accurate is Project Sunroof's system size recommendation?
A: The recommended system size is based on your roof's usable area and the monthly bill you enter, and it's a reasonable starting point — typically within 1–2 kW of what a qualified installer would recommend. The bigger limitation is that it doesn't account for your specific usage pattern, EV charging loads, or planned electrification upgrades. Use it as a first estimate and verify with PVWatts.
Q: Why can't I just use Project Sunroof's savings estimate?
A: Project Sunroof's financial data hasn't been meaningfully updated since approximately 2018. In 2026, three major things have changed that aren't reflected in its model: installed costs have dropped, the federal 30% tax credit no longer applies to homeowners, and California's NEM 3.0 cuts export compensation by about 75% compared to the rates Project Sunroof assumes. Its savings estimates for California can be overstated by $2,000–$5,000+ per year depending on your usage.
Q: Is NREL PVWatts really free with no contact information required?
A: Yes. PVWatts is a government-maintained tool (National Renewable Energy Laboratory, U.S. Department of Energy) with no commercial interest in capturing your contact details. You enter location and system parameters, and it returns production estimates. No account, no email, no phone number — at any step.
Q: Can AI tools make calculation errors I should watch out for?
A: Yes — two specific areas to verify. First, utility rate inputs: AI tools may have slightly outdated or averaged rate data. Always cross-check any rate figures the AI uses against your current utility bill or your utility's published rate schedule. Second, NEM 3.0 export rate assumptions: the avoided cost rates fluctuate by time of day and season. For planning purposes, $0.05–$0.08/kWh is a reasonable annual average for California daytime exports, but the actual rate varies. The AI's calculation logic and step-by-step reasoning are generally reliable; the input data deserves verification.
Q: When should I actually contact an installer?
A: Once you've done this three-tool workflow and have a solid sense of your system size, expected production, approximate cost range, and estimated payback, you're ready to get actual quotes. At that point, requesting quotes from at least three CSLB-licensed installers (verify at cslb.ca.gov, look for C-46 solar contractor license) gives you competitive pricing with enough context to evaluate what they're proposing. You're no longer starting from zero — you know what a fair proposal looks like.
Q: Does this workflow work for homes with complex roofs or significant shading?
A: It works as a starting point, but complex situations limit accuracy. If your home has multiple roof faces pointing in different directions, significant tree shading, or dormer windows that break up usable area, Project Sunroof and PVWatts both become less reliable. In those cases, the three-tool workflow gives you a directional estimate — good enough to know whether solar makes sense — but a licensed installer with proper shade analysis software (like Aurora or Helioscope) will give you a more accurate system design.
Q: What if Project Sunroof doesn't have data for my address?
A: Project Sunroof covers more than 43 million U.S. rooftops, but some addresses — particularly newer construction, rural areas, or homes with unusual footprints — may show incomplete data. In that case, skip directly to PVWatts: enter your zip code instead of your address, use a typical tilt and azimuth for your region, and estimate system size based on your square footage (roughly 100 sq ft of south-facing roof per 1 kW of solar). The AI tool can help you work through the calculation with estimated inputs.
Conclusion: Research First, Talk to Installers Second
The Torrance homeowner I mentioned at the beginning eventually did go solar — about six weeks after that first conversation. She used Project Sunroof to understand her roof, PVWatts to validate the production estimate, and an AI tool to run the savings math before she contacted anyone. When she finally did call an installer, she knew her system should be around 7 kW, that the fair installed cost was in the $16,000–$18,000 range, and that her payback period under NEM 3.0 was realistically 9–10 years without a battery.
The installer she chose said she was one of the most prepared homeowners he'd worked with. She ended up getting a lower price than his initial quote because she could explain exactly what she needed and why, and she walked away without any surprises.
Getting a Google Project Sunroof solar estimate with no contact info isn't about avoiding the solar industry — it's about entering that conversation on equal footing.
The three-step process that makes it work:
Step 1: Go to sunroof.withgoogle.com, enter your address, and record your annual sun hours, usable roof area, and recommended system size. Ignore all dollar figures.
Step 2: Go to pvwatts.nrel.gov, enter your address and the system size from Step 1, and record your annual kWh production estimate and monthly breakdown.
Step 3: Open ChatGPT or Claude, paste the prompt template from this guide with your actual numbers, and work through the savings and payback calculation specific to your utility and NEM status.
Then, when you're ready: contact three CSLB-licensed installers, share your estimate framework, and ask them to beat it.
Related Posts
Sources
Google Project Sunroof — tool and methodology: sunroof.withgoogle.com
NREL PVWatts Calculator: pvwatts.nrel.gov
EnergySage — California Solar Market Report (April 2026), installed cost data: energysage.com
EcoWatch — Project Sunroof accuracy review (2025): ecowatch.com
CPUC — NEM 3.0 / Net Billing Tariff rate data: cpuc.ca.gov
SCE TOU-D-PRIME 2026 rate schedule: sce.com
PG&E E-ELEC 2026 rate schedule: pge.com
SDG&E EV-TOU-5 2026 rate schedule: sdge.com
CSLB contractor license verification: cslb.ca.gov
About the Author
Hi, I'm James Ree, founder of ElecGuys. With 8 years of experience in electrical, HVAC, and solar wholesale in Los Angeles, I used to consult contractors and supply equipment for residential and commercial projects. I now run this blog full-time to share clear, honest, and practical information with homeowners who are new to solar and home energy. My goal is simple: to help you save money, avoid costly mistakes, and make smarter energy decisions.
Disclaimer
Cost estimates, tool features, and utility rate structures can change over time and vary by location. The AI-generated calculations in this guide are illustrative examples based on publicly available 2026 California data. Always verify production estimates and savings projections with a licensed solar contractor (CSLB C-46) before making any purchasing decisions.
