Solar panels in San Diego, CA

Roofs in San Diego get about 1,894 hours of usable sunlight a year — more than 89% 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 Diego → City averages are a starting point; your own roof's size, pitch and shading change the answer a lot.

What a typical San Diego solar system costs

A 17-panel system (6.8 kW) is about right for an average San Diego home using 10,800 kWh a year. It would produce roughly 10,947 kWh annually and offset 100% of that usage.

How we worked this out for San Diego

Every number on this page comes from these seven steps. Nothing is a national average — the sunlight figure is measured from San Diego rooftops.

Step 6 is where most calculators quietly overstate things. Only 35% of what a system this size produces in San Diego is used the moment it is generated; the other 7,167 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 4.0 years instead of the 8.3 we show. That 4.3-year difference is the single biggest reason our figures look worse than other sites' for San Diego.

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 Diego gets 1,894 sun hours

That figure comes from Google's analysis of real rooftops across San Diego — 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 Diego reaches about 1,973 hours, roughly 4% better than typical.

The numbers behind this page

When San Diego actually produces

Annual totals hide the thing that catches people out: 33% of San Diego's yearly sunlight arrives in May–July, and just 16% across November–January.

Output is unusually steady — only about 2.3× between Jun and Dec. San Diego 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 San Diego's latitude, not separately measured, so treat the monthly figures as the shape of a typical year rather than a forecast.

How San Diego compares to the other 788 cities

What actually stands out about San Diego:

• Plenty of roof to work with. Typical roofs here fit around 74 panels — roughly 4× what an average home needs. Roof size will not be what limits your system in San Diego.
• 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 Diego's 1,894 usable sun hours from other states and provinces. Same sunlight, different electricity prices — which is usually what decides whether solar is worth it.

Nearby cities

See all of California → statewide sunlight, rates, incentives and every city we've measured.

San Diego solar questions

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.