Solar panels in Rancho Cucamonga, CA
Roofs in Rancho Cucamonga get about 1,958 hours of usable sunlight a year — more than 94% 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 Rancho Cucamonga → City averages are a starting point; your own roof's size, pitch and shading change the answer a lot.
What a typical Rancho Cucamonga solar system costs
A 17-panel system (6.8 kW) is about right for an average Rancho Cucamonga home using 10,800 kWh a year. It would produce roughly 11,317 kWh annually and offset 100% of that usage.
| System | Size | kWh/yr | Net cost | Saves/yr | Payback |
|---|---|---|---|---|---|
| 8 panels | 3.2 kW | 5,326 | $6,384 | $1,276 | 5 yrs |
| 12 panels | 4.8 kW | 7,989 | $9,576 | $1,442 | 6.6 yrs |
| 16 panels | 6.4 kW | 10,652 | $12,768 | $1,608 | 7.9 yrs |
| 20 panels | 8 kW | 13,314 | $15,960 | $1,774 | 9 yrs |
| 26 panels | 10.4 kW | 17,309 | $20,748 | $2,024 | 10.3 yrs |
How we worked this out for Rancho Cucamonga
Every number on this page comes from these seven steps. Nothing is a national average — the sunlight figure is measured from Rancho Cucamonga rooftops.
| # | Step | Result |
|---|---|---|
| 1 | What one panel makes here 400W ÷ 1000 × 1,958 sun hrs × 0.85 system losses |
666 kWh/yr |
| 2 | Panels needed to cover typical usage 10,800 kWh ÷ 666 kWh per panel |
17 panels |
| 3 | System size 17 panels × 400W |
6.80 kW |
| 4 | Annual production 6.80 kW × 1,958 hrs × 0.85 |
11,317 kWh/yr |
| 5 | Installed cost 6,800 W × $2.85 per watt, then −30% federal credit |
$13,566 |
| 6 | Annual saving 3,780 kWh used as generated × 31.2¢ + 7,537 kWh exported × 6.2¢ |
$1,650/yr |
| 7 | Payback $13,566 ÷ $1,650 per year |
8.2 years |
Step 6 is where most calculators quietly overstate things. Only 33% of what a system this size produces in Rancho Cucamonga is used the moment it is generated; the other 7,537 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 3.8 years instead of the 8.2 we show. That 4.4-year difference is the single biggest reason our figures look worse than other sites' for Rancho Cucamonga.
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 Rancho Cucamonga gets 1,958 sun hours
That figure comes from Google's analysis of real rooftops across Rancho Cucamonga — 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 Rancho Cucamonga reaches about 2,024 hours, roughly 3% better than typical.
The numbers behind this page
| Typical usable sunlight | 1,958 hrs/yr |
|---|---|
| Unshaded roof | 2,024 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 | 33% |
| Paid for exported power | 20% of retail |
| Rooftops sampled here | 14 |
| Google imagery from | 2023 |
When Rancho Cucamonga actually produces
Annual totals hide the thing that catches people out: 34% of Rancho Cucamonga's yearly sunlight arrives in May–July, and just 15% across November–January.
| Month | Sun hrs | Share of year |
|---|---|---|
| Jan | 101 | |
| Feb | 128 | |
| Mar | 162 | |
| Apr | 194 | |
| May | 216 | |
| Jun | 224 | |
| Jul | 219 | |
| Aug | 202 | |
| Sep | 173 | |
| Oct | 138 | |
| Nov | 108 | |
| Dec | 94 |
Output is unusually steady — only about 2.4× between Jun and Dec. Rancho Cucamonga is close enough to the equator that seasonal variation is mild, which makes sizing a system considerably more predictable.
The annual total is measured from Google's rooftop imagery. Its split across months is calculated from solar geometry at Rancho Cucamonga's latitude, not separately measured, so treat the monthly figures as the shape of a typical year rather than a forecast.
How Rancho Cucamonga compares to the other 788 cities
| Measure | Rancho Cucamonga | Rank of 788 |
|---|---|---|
| Usable sunlight | 1,958 hrs | 50th |
| Sunlight lost to shade | 3% | 606th most |
| Median roof size | 238 m² | 248th largest |
| Electricity rate | 31.2¢ | 27th highest |
| Payback | 8.2 yrs | 101st fastest |
| Grid carbon | 429 kg/MWh | 678th dirtiest |
What actually stands out about Rancho Cucamonga:
- Plenty of roof to work with. Typical roofs here fit around 84 panels — roughly 4× what an average home needs. Roof size will not be what limits your system in Rancho Cucamonga.
- The case here is financial, not environmental. Rancho Cucamonga's grid is already clean at 429 kg CO₂ per MWh, so the carbon saving from solar is modest. Judge this one on payback.
- 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 Rancho Cucamonga's 1,958 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 |
|---|---|---|---|
| Gallup, NM | 1,960 | 14.8¢ | 8.4 yrs |
| Rio Rancho, NM | 1,965 | 14.8¢ | 8.4 yrs |
| Moab, UT | 1,967 | 11.2¢ | 11.1 yrs |
| Albuquerque, NM | 1,948 | 14.8¢ | 8.4 yrs |
Nearby cities
See all of California → statewide sunlight, rates, incentives and every city we've measured.
Rancho Cucamonga solar questions
How many solar panels do I need in Rancho Cucamonga?
About 17 panels for an average home using 10,800 kWh a year. Rancho Cucamonga roofs get 1,958 usable sun hours, so each 400W panel produces roughly 666 kWh annually. A typical Rancho Cucamonga roof fits about 84 panels, so roof space is unlikely to be your limit.
Is solar worth it in Rancho Cucamonga?
At 31.2¢/kWh and 1,958 sun hours, a typical system pays for itself in about 8.2 years and returns roughly $27,676 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 Rancho Cucamonga?
A 6.8 kW system costs about $19,380 before incentives and $13,566 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.