- Range in the 30 US cities we modeled: about 390 kWh (vertical, facing west, Pittsburgh) to 1,450 kWh (tilted, south, Las Vegas or Phoenix).
- A kit on a south-facing balcony railing produces about 570-920 kWh a year without shade.
- Location sets the ceiling; mounting and shade decide how close you get.
In this article
Yearly production of an 800 W kit in 30 US cities (kWh)
| City | Vertical, south | Vertical, east | Vertical, west | Tilted 30°, south | Flat |
|---|---|---|---|---|---|
| Phoenix, AZ | 880 | 690 | 660 | 1,440 | 1,260 |
| Las Vegas, NV | 920 | 700 | 670 | 1,450 | 1,240 |
| Los Angeles, CA | 820 | 580 | 680 | 1,360 | 1,200 |
| San Diego, CA | 760 | 520 | 650 | 1,240 | 1,100 |
| San Francisco, CA | 830 | 570 | 660 | 1,330 | 1,150 |
| Sacramento, CA | 810 | 640 | 590 | 1,310 | 1,140 |
| Salt Lake City, UT | 800 | 600 | 580 | 1,220 | 1,040 |
| Denver, CO | 890 | 640 | 580 | 1,300 | 1,090 |
| Austin, TX | 700 | 560 | 600 | 1,210 | 1,100 |
| Miami, FL | 670 | 620 | 580 | 1,240 | 1,160 |
| Atlanta, GA | 740 | 580 | 570 | 1,190 | 1,050 |
| Richmond, VA | 750 | 560 | 530 | 1,140 | 980 |
| Washington, DC | 730 | 530 | 520 | 1,100 | 940 |
| Baltimore, MD | 740 | 540 | 510 | 1,100 | 940 |
| Wilmington, DE | 730 | 530 | 510 | 1,090 | 930 |
| Philadelphia, PA | 730 | 520 | 500 | 1,080 | 920 |
| Pittsburgh, PA | 570 | 410 | 390 | 930 | 840 |
| Newark, NJ | 750 | 530 | 510 | 1,090 | 920 |
| New York City, NY | 720 | 520 | 460 | 1,070 | 910 |
| Buffalo, NY | 620 | 470 | 470 | 950 | 840 |
| Hartford, CT | 730 | 510 | 500 | 1,050 | 880 |
| Boston, MA | 750 | 530 | 490 | 1,080 | 900 |
| Concord, NH | 740 | 520 | 500 | 1,040 | 870 |
| Burlington, VT | 680 | 470 | 470 | 980 | 830 |
| Portland, ME | 750 | 510 | 500 | 1,060 | 880 |
| Chicago, IL | 690 | 500 | 500 | 1,050 | 910 |
| Minneapolis, MN | 750 | 520 | 500 | 1,060 | 880 |
| Seattle, WA | 640 | 420 | 470 | 930 | 790 |
| Portland, OR | 610 | 440 | 470 | 920 | 790 |
| Honolulu, HI | 620 | 660 | 650 | 1,320 | 1,280 |
Our PVGIS 5.2 runs with NSRDB satellite data (2005-2015 average), 800 W, 14% system losses, no shade from buildings or trees. Individual years vary by a few percent. Findings and method: our 30-city data. For London or Berlin, expect roughly 800 kWh tilted and 580 kWh on a south railing (rule-of-thumb estimate).
Why real-world output is lower than “800 W × hours of sun”
- Panels rarely receive full-strength sunlight at a perfect angle.
- Heat reduces efficiency in summer.
- Inverter and wiring losses of a few percent.
- Clipping if panels exceed the inverter’s 800 W on bright days (small effect).
Estimate your own
Use the calculator or see solar yield by region to understand the numbers behind this table.
From yearly kWh to daily expectations
Divide the yearly figure by 365 for an average day: a kit making 700 kWh a year averages about 1.9 kWh per day. Output swings through the year, though. A tilted panel makes more in June than in December everywhere, up to three times more in cloudy Seattle or Buffalo. A vertical south-facing panel often does the opposite: in Phoenix it makes almost four times more in December than in June. See a year of balcony solar, month by month.
What reduces output below the table
- Shade: the largest and most common factor. How shade works.
- Heat: panels flat against a hot wall run warmer and lose a few percent.
- Dirt: a few percent on tilted or flat panels. Cleaning.
- Inverter limits: an inverter set to 600 W will clip on bright days.
- Orientation between the columns: south-east or south-west sits between south and east/west values.
How the numbers were calculated
The table comes from our own runs of PVGIS 5.2, the European Commission’s free solar calculator, with NSRDB satellite data averaged over 2005-2015: 800 W of crystalline panels, 14% system losses, free-standing mounting and no shade apart from the distant horizon. Full method and findings: our 30-city data. For other addresses, solar yield by region explains the quicker rule-of-thumb method used by our calculator.
Turning kWh into dollars
| Yearly output | At $0.15/kWh | At $0.20/kWh | At $0.30/kWh |
|---|---|---|---|
| 600 kWh | $68 | $90 | $135 |
| 800 kWh | $90 | $120 | $180 |
| 1,000 kWh | $113 | $150 | $225 |
| 1,200 kWh | $135 | $180 | $270 |
Assumes 75% self-consumption and no payment for exports.
Frequently asked questions
Is 800 W of panels the same as an 800 W kit?
Not always. Some kits pair 880-1,000 Wp of panels with an 800 W inverter, which increases yearly production slightly, especially on vertical mounts.
How much will production fall over time?
About 0.3-0.5% a year for good panels, so a kit making 700 kWh today should still make over 630 kWh after 20 years.
Can I check my estimate precisely?
Yes: use PVWatts from the National Laboratory of the Rockies (formerly NREL) or the EU’s PVGIS with your address and 90° tilt for vertical mounting, or the calculator for a quick estimate.
Sources
- PVWatts Calculator, National Laboratory of the Rockies (formerly NREL).
- Photovoltaic Geographical Information System (PVGIS), European Commission, Joint Research Centre.
- Photovoltaic degradation rates: an analytical review (Jordan and Kurtz), NREL / National Laboratory of the Rockies.
- Solar photovoltaic performance and efficiency basics, U.S. Department of Energy.
Sources checked in September 2026. Laws, prices and product details change; if you spot something out of date, tell us.