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Sun hours / solar resource
Updated August 6, 2026 · based on NREL PVWatts / NSRDB sun-hour data · by Cali Energy
How many peak sun hours does Los Angeles get? About 5.8 a day — so each 1 kW of panels makes roughly 1,690 kWh a year here. That’s well above the U.S. average and nearly double a cloudier city like Berlin (~3.0). Peak sun hours are the single input that most drives any solar production estimate.
✓ Peak sun hours from NREL PVWatts / NSRDB solar-resource data. See every figure it uses ↓
Peak sun hours and annual output per kilowatt.
Peak sun hours from NREL solar-resource data (NSRDB/PVWatts); output = sun hours × 365 × ~0.80 for typical system losses. Planning estimate — actual production depends on roof orientation, tilt, shading and equipment.
The rates and figures this calculator usestap to verify
Peak sun hours turn a day’s sunlight into a number of full-strength hours — the base input for expected production. Here are the daily averages the tool uses and how it turns them into output.
| Los Angeles | ~5.8 |
| Phoenix | ~6.5 |
| Miami | ~5.5 |
| New York | ~4.0 |
| Seattle | ~3.5 |
| Annual output per kW | sun hours × 365 × ~0.80 losses |
| Relative to LA | that area’s sun hours ÷ 5.8 |
U.S. peak sun hours are NREL NSRDB/PVWatts annual daily averages; Berlin is from the EU’s PVGIS — the two databases use different methods, so treat the cross-country comparison as indicative, not exact. Figures are city-level annual averages and individual neighborhoods vary. The ~0.80 factor rolls up typical system losses (inverter, wiring, soiling, temperature). Los Angeles’s mild, dry climate also helps panels run efficiently and stay clean, so real-world output often lands closer to sunnier cities than the raw sun-hour gap suggests.
Example results you can reproduce
Select each location above to see the same figures — annual output assumes ~0.80 system losses.
| Location | Peak sun hours/day | Annual output per 1 kW |
|---|---|---|
| Los Angeles | ~5.8 | ~1,694 kWh |
| Phoenix | ~6.5 | ~1,898 kWh |
| Miami | ~5.5 | ~1,606 kWh |
| New York | ~4.0 | ~1,168 kWh |
| Seattle | ~3.5 | ~1,022 kWh |
| Berlin, Germany | ~3.0 | ~876 kWh |
How this calculator works
It looks up each area’s average daily peak sun hours — NREL NSRDB/PVWatts for the U.S. cities, EU PVGIS for Berlin — then estimates annual output per kilowatt as sun hours × 365 × ~0.80 for typical system losses. The “relative to LA” figure simply divides that area’s sun hours by Los Angeles’s 5.8, so you can see at a glance how the solar resource compares.
How to read your result
Three numbers: daily peak sun hours, the annual kWh a single kW of panels makes there, and how that stacks up against LA. To go from these to a system, multiply the per-kW output by your system size — a 6 kW LA array is about 6 × 1,694 ≈ 10,000 kWh a year.
What moves the result the most
Latitude and climate set the sun hours, and sun hours set most of the output. But raw hours aren’t the whole story: hot climates lose a little to heat, cloudy-then-clear regions vary year to year, and a clean, cool, well-angled roof narrows the gap. Tilt, azimuth and shading then adjust the number for your specific roof.
Common questions
What is a peak sun hour?
An hour of full-strength sunlight (1,000 W/m²). A whole day’s sunlight is expressed as an equivalent count of these full hours, which makes locations easy to compare.
How many peak sun hours does Los Angeles get?
About 5.8 a day as an annual average — higher in summer, lower in winter. That’s among the better solar resources in the country and well above the U.S. average near 5.
How do sun hours become kWh?
Multiply sun hours by 365 and by about 0.80 for system losses to get annual output per kW, then multiply by your system size. So 1 kW in LA makes roughly 1,690 kWh a year.
Is more sun always more output?
Mostly, but not perfectly — very hot climates lose a little output to heat, so a scorching desert doesn’t beat a mild sunny coast by quite as much as the raw sun hours imply.
If Germany has so little sun, why so much solar?
Policy and economics, not sunshine. Germany built a world-leading solar industry on ~3 sun hours a day — Los Angeles has nearly double that resource, so panels here pay back on sunlight Germany can only envy.
Does my exact neighborhood differ?
A little — coastal marine layer, inland heat and local terrain shift the number. For a precise, address-level figure, run the free NREL PVWatts calculator.
Sources
- NREL — National Solar Radiation Database (NSRDB)
- NREL — PVWatts Calculator
- NREL — Solar Resource Maps and Data
- NREL — Solar Radiation Data Manual (Redbook)
- EU Science Hub — PVGIS (Photovoltaic Geographical Information System)
Estimates only, not a quote. Assumptions, rates, incentives and program rules can change — confirm current details with your utility, the program administrator or a licensed professional.
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