Peak sun hours by US city
Peak sun hours in 20 US cities range from 3.03 a day in Anchorage to 6.57 in Phoenix, using NREL PVWatts v8 with panels tilted at the local latitude and facing south. Chicago gets 4.46, Denver 5.74 and Seattle 3.83. Each 1 kW of panels makes about 886 to 1,817 kWh of AC power a year.
Last updated: October 10, 2026.
Built by Jeremy Panasuk.
Each row is an NREL PVWatts v8 run for a 1 kW system: fixed open rack, tilt equal to the city latitude, facing south (azimuth 180), 14% system losses and a standard module. Peak sun hours are the annual average solar radiation on the panel, in kWh/m² per day. Annual AC kWh is what that 1 kW of panels produces in a year under the same settings.
The data (20 rows)
Figures as published by NREL PVWatts v8. Sources accessed October 10, 2026. Each row links to the page or document the number was read from.
| City | Peak sun hours (kWh/m²/day) | Annual AC kWh per 1 kW of panels | Weather data | Source |
|---|---|---|---|---|
| Phoenix, AZ | 6.57 | 1,787 | NSRDB PSM V3 GOES tmy-2020 3.2.0 | NREL PVWatts v8 |
| Las Vegas, NV | 6.47 | 1,791 | NSRDB PSM V3 GOES tmy-2020 3.2.0 | NREL PVWatts v8 |
| Los Angeles, CA | 6.09 | 1,699 | NSRDB PSM V3 GOES tmy-2020 3.2.0 | NREL PVWatts v8 |
| Denver, CO | 5.74 | 1,635 | NSRDB PSM V3 GOES tmy-2020 3.2.0 | NREL PVWatts v8 |
| Albuquerque, NM | 6.48 | 1,817 | NSRDB PSM V3 GOES tmy-2020 3.2.0 | NREL PVWatts v8 |
| Dallas, TX | 5.41 | 1,513 | NSRDB PSM V3 GOES tmy-2020 3.2.0 | NREL PVWatts v8 |
| Houston, TX | 5.15 | 1,422 | NSRDB PSM V3 GOES tmy-2020 3.2.0 | NREL PVWatts v8 |
| Miami, FL | 5.57 | 1,552 | NSRDB PSM V3 GOES tmy-2020 3.2.0 | NREL PVWatts v8 |
| Atlanta, GA | 5.09 | 1,412 | NSRDB PSM V3 GOES tmy-2020 3.2.0 | NREL PVWatts v8 |
| Nashville, TN | 4.77 | 1,342 | NSRDB PSM V3 GOES tmy-2020 3.2.0 | NREL PVWatts v8 |
| Kansas City, MO | 5.05 | 1,451 | NSRDB PSM V3 GOES tmy-2020 3.2.0 | NREL PVWatts v8 |
| Chicago, IL | 4.46 | 1,308 | NSRDB PSM V3 GOES tmy-2020 3.2.0 | NREL PVWatts v8 |
| Minneapolis, MN | 4.66 | 1,358 | NSRDB PSM V3 GOES tmy-2020 3.2.0 | NREL PVWatts v8 |
| Milwaukee, WI | 4.55 | 1,337 | NSRDB PSM V3 GOES tmy-2020 3.2.0 | NREL PVWatts v8 |
| Detroit, MI | 4.42 | 1,287 | NSRDB PSM V3 GOES tmy-2020 3.2.0 | NREL PVWatts v8 |
| New York, NY | 4.45 | 1,293 | NSRDB PSM V3 GOES tmy-2020 3.2.0 | NREL PVWatts v8 |
| Boston, MA | 4.71 | 1,329 | NSRDB PSM V3 GOES tmy-2020 3.2.0 | NREL PVWatts v8 |
| Seattle, WA | 3.83 | 1,071 | NSRDB PSM V3 GOES tmy-2020 3.2.0 | NREL PVWatts v8 |
| Portland, OR | 3.98 | 1,113 | NSRDB PSM V3 GOES tmy-2020 3.2.0 | NREL PVWatts v8 |
| Anchorage, AK | 3.03 | 886 | NSRDB PSM V4 Polar tmy-2023 1.0.0 | NREL PVWatts v8 |
Download
Download the CSV (20 rows, updated 2026-10-10). Same rows as the table, plus each row's source URL and access date.
Cite this data
Suggested citation:
Panasuk, J. (2026). Peak sun hours by US city. solar-sizer.com. https://solar-sizer.com/peak-sun-hours-by-city.html (accessed YYYY-MM-DD). Underlying figures: NREL PVWatts v8 (https://pvwatts.nrel.gov/).
BibTeX:
@misc{panasuk2026solarsizer,
author = {Panasuk, Jeremy}, title = {Peak sun hours by US city}, year = {2026},
howpublished = {\url{https://solar-sizer.com/peak-sun-hours-by-city.html}}, note = {Data from NREL PVWatts v8, https://pvwatts.nrel.gov/; accessed YYYY-MM-DD} }
Please cite the original source too. Questions or corrections: [email protected].
Sources
- NREL PVWatts v8: https://pvwatts.nrel.gov/. Accessed October 10, 2026.
License
All rights reserved. Citation and non-commercial reuse are fine with a link back to this page. The underlying figures belong to the original publishers; this page only compiles them.
Use it with the calculator
Run your own numbers on the homepage calculator. How this site handles sources is on the methodology page. Related guides: how many solar panels, what size solar system, off grid cabin solar, what size solar system for 5 kwh per day.
Compiled with AI assistance from the sources linked above. Spot an error? Email [email protected].