Solar panels in San Jose, CA
Roofs in San Jose get about 1,810 hours of usable sunlight a year — more than 84% of the cities we've measured. Here's what that means in cost, savings and payback, using real rooftop data rather than a national average.
Check your specific roof in San Jose → City averages are a starting point; your own roof's size, pitch and shading change the answer a lot.
What a typical San Jose solar system costs
A 18-panel system (7.2 kW) is about right for an average San Jose home using 10,800 kWh a year. It would produce roughly 11,077 kWh annually and offset 100% of that usage.
| System | Size | kWh/yr | Net cost | Saves/yr | Payback |
|---|---|---|---|---|---|
| 8 panels | 3.2 kW | 4,923 | $6,384 | $1,251 | 5.1 yrs |
| 12 panels | 4.8 kW | 7,385 | $9,576 | $1,404 | 6.8 yrs |
| 16 panels | 6.4 kW | 9,846 | $12,768 | $1,558 | 8.2 yrs |
| 20 panels | 8 kW | 12,308 | $15,960 | $1,712 | 9.3 yrs |
| 26 panels | 10.4 kW | 16,000 | $20,748 | $1,942 | 10.7 yrs |
How we worked this out for San Jose
Every number on this page comes from these seven steps. Nothing is a national average — the sunlight figure is measured from San Jose rooftops.
| # | Step | Result |
|---|---|---|
| 1 | What one panel makes here 400W ÷ 1000 × 1,810 sun hrs × 0.85 system losses |
615 kWh/yr |
| 2 | Panels needed to cover typical usage 10,800 kWh ÷ 615 kWh per panel |
18 panels |
| 3 | System size 18 panels × 400W |
7.20 kW |
| 4 | Annual production 7.20 kW × 1,810 hrs × 0.85 |
11,077 kWh/yr |
| 5 | Installed cost 7,200 W × $2.85 per watt, then −30% federal credit |
$14,364 |
| 6 | Annual saving 3,780 kWh used as generated × 31.2¢ + 7,297 kWh exported × 6.2¢ |
$1,635/yr |
| 7 | Payback $14,364 ÷ $1,635 per year |
8.8 years |
Step 6 is where most calculators quietly overstate things. Only 34% of what a system this size produces in San Jose is used the moment it is generated; the other 7,297 kWh is exported and credited at 20% of retail under net billing. Valuing every kWh at the full 31.2¢ retail rate — which many calculators do — would show a payback of 4.2 years instead of the 8.8 we show. That 4.6-year difference is the single biggest reason our figures look worse than other sites' for San Jose.
Assumptions: 400W panels, 15% system losses (inverter, wiring, heat, soiling), $2.85/W installed, 10,800 kWh typical annual household use, 31.2¢/kWh electricity. Change any of those and every figure above moves — which is exactly why a single national "solar costs X" number is misleading.
Notice that payback barely improves as systems get bigger, and eventually gets worse. That's because you can only save money on electricity you were going to buy anyway. Once a system covers your usage, extra panels mostly generate exports at a much lower rate.
Why San Jose gets 1,810 sun hours
That figure comes from Google's analysis of real rooftops across San Jose — it already accounts for shading from trees, chimneys and neighbouring buildings, which is why it's lower than the raw "hours of daylight" figures you'll see elsewhere. An unusually open, unshaded roof in San Jose reaches about 1,936 hours, roughly 7% better than typical.
The numbers behind this page
| Typical usable sunlight | 1,810 hrs/yr |
|---|---|
| Unshaded roof | 1,936 hrs/yr |
| Electricity rate (California avg) | 31.2¢/kWh |
| Installed cost assumed | $2.85/W |
| Panel size assumed | 400 W |
| Federal tax credit | 30% |
| Typical household usage | 10,800 kWh/yr |
| Power used as generated | 34% |
| Paid for exported power | 20% of retail |
| Rooftops sampled here | 16 |
| Google imagery from | 2023 |
When San Jose actually produces
Annual totals hide the thing that catches people out: 35% of San Jose's yearly sunlight arrives in May–July, and just 14% across November–January.
| Month | Sun hrs | Share of year |
|---|---|---|
| Jan | 87 | |
| Feb | 114 | |
| Mar | 148 | |
| Apr | 182 | |
| May | 206 | |
| Jun | 215 | |
| Jul | 210 | |
| Aug | 191 | |
| Sep | 160 | |
| Oct | 124 | |
| Nov | 93 | |
| Dec | 80 |
San Jose produces about 2.7× as much in Jun as in Dec — a normal mid-latitude swing. Expect real winter shortfall and summer surplus rather than steady year-round output.
The annual total is measured from Google's rooftop imagery. Its split across months is calculated from solar geometry at San Jose's latitude, not separately measured, so treat the monthly figures as the shape of a typical year rather than a forecast.
How San Jose compares to the other 788 cities
| Measure | San Jose | Rank of 788 |
|---|---|---|
| Usable sunlight | 1,810 hrs | 125th |
| Sunlight lost to shade | 7% | 247th most |
| Median roof size | 293 m² | 132nd largest |
| Electricity rate | 31.2¢ | 8th highest |
| Payback | 8.8 yrs | 199th fastest |
| Grid carbon | 429 kg/MWh | 659th dirtiest |
What actually stands out about San Jose:
- Plenty of roof to work with. Typical roofs here fit around 92 panels — roughly 5× what an average home needs. Roof size will not be what limits your system in San Jose.
- Dimmer than the rest of California. San Jose roofs get 6% less usable sunlight than the typical California city we've measured — statewide averages will overstate what you can expect here.
- Expensive electricity works in your favour. At 31.2¢/kWh, California is among the priciest places to buy power — which is exactly what makes generating your own pay back faster.
Cities with almost the same sunlight
These are the closest matches to San Jose's 1,810 usable sun hours from other states and provinces. Same sunlight, different electricity prices — which is usually what decides whether solar is worth it.
| City | Sun hrs | Rate | Payback |
|---|---|---|---|
| Cape Coral, FL | 1,810 | 15.3¢ | 8.6 yrs |
| Colorado Springs, CO | 1,808 | 14.8¢ | 8.9 yrs |
| Bradenton, FL | 1,812 | 15.3¢ | 8.6 yrs |
| Miami, FL | 1,807 | 15.3¢ | 8.6 yrs |
Nearby cities
See all of California → statewide sunlight, rates, incentives and every city we've measured.
San Jose solar questions
How many solar panels do I need in San Jose?
About 18 panels for an average home using 10,800 kWh a year. San Jose roofs get 1,810 usable sun hours, so each 400W panel produces roughly 615 kWh annually. A typical San Jose roof fits about 92 panels, so roof space is unlikely to be your limit.
Is solar worth it in San Jose?
At 31.2¢/kWh and 1,810 sun hours, a typical system pays for itself in about 8.8 years and returns roughly $26,504 over a 25-year panel life. That is a solid return, and it improves further if electricity prices rise. Exports earn only 20% of retail, so using power as you generate it matters.
How much do solar panels cost in San Jose?
A 7.2 kW system costs about $20,520 before incentives and $14,364 after the 30% federal tax credit. That works out near $2.85 per watt installed. Roof pitch, shading, electrical panel upgrades and equipment choice move the price most, which is why quotes for the same house can differ by thousands.
Worth reading before you buy
Estimates only, generated 2026-08-22 from Google Solar API rooftop samples and average California electricity rates. Not a quote and not financial advice. Your roof, usage, utility plan and local incentives will change these numbers — get real quotes before buying.