Short answer
Yes, a balcony kit keeps working in winter, and on an upright railing it can make more then than in summer. In our calculator, a south-facing railing kit made more from December to February than from June to August in eight of nine cities (all but Seattle), because the low winter sun hits upright panels square on. Savings don't collapse in winter on either mount: the weakest month still saved 39%–82% of the strongest month. On a railing, what winter cuts is how much of the output your home can use, because it comes in a short burst around midday.
Winter against summer, north to south
The same 800 W kit facing south, upright on a railing and tilted on a patio, in nine cities from Seattle to Miami. Winter is December to February, summer June to August. Each city uses its state's average electricity rate, the home has a steady 150 W always-on load, and power sent to the grid earns nothing.
| City | Rate | Railing (upright, 90°) | Patio (tilted 30°) | ||||
|---|---|---|---|---|---|---|---|
| Winter | Summer | Winter savings | Winter | Summer | Winter savings | ||
| Seattle, WA | 14.2¢ | 120 | 150 | 17% | 110 | 330 | 15% |
| Minneapolis, MN | 16.2¢ | 250 | 150 | 22% | 210 | 340 | 19% |
| Burlington, VT | 23.9¢ | 210 | 140 | 22% | 180 | 310 | 19% |
| Boston, MA | 30.4¢ | 230 | 130 | 22% | 210 | 310 | 19% |
| New York, NY | 28.4¢ | 210 | 120 | 23% | 210 | 320 | 19% |
| Denver, CO | 16.6¢ | 290 | 130 | 24% | 280 | 360 | 21% |
| Los Angeles, CA | 33.1¢ | 260 | 110 | 25% | 280 | 390 | 21% |
| Phoenix, AZ | 15.5¢ | 300 | 110 | 25% | 310 | 370 | 22% |
| Miami, FL | 15.4¢ | 240 | 80 | 28% | 300 | 300 | 23% |
"Winter savings" is the share of the year's savings that came in December, January and February; three even months would be 25%. Each city name opens its railing result page.
Why an upright panel likes winter
In summer the sun stands high at midday, so its light glances off an upright panel at a steep angle. In winter it stays low in the southern sky and hits the same panel almost head-on. A panel tilted at 30° faces the high summer sun better, so it makes most of its power from spring to early fall.
That's why, in Boston, the railing kit made 230 kWh in winter and 130 kWh in summer, while the patio kit made 210 kWh and 310 kWh. Over the whole year the patio still came out ahead: $146 against $123.
Boston, month by month
Winter output comes in a few hours around midday, often more than the home's always-on load can use at once. On a railing, that sends a bigger share to the grid in winter: homes used 37%–52% of the kit's winter output but 70%–98% of its summer output. On a patio, where the summer peak is bigger too, the shares were closer: 37%–57% in winter, 38%–46% in summer.
Railing (upright, 90°)
Patio (tilted 30°)
| Month | Railing (upright, 90°) | Patio (tilted 30°) | ||||
|---|---|---|---|---|---|---|
| Made | Used | Saved | Made | Used | Saved | |
| Jan | 90 | 30 | $9 | 70 | 30 | $9 |
| Feb | 80 | 30 | $10 | 80 | 30 | $10 |
| Mar | 90 | 40 | $12 | 100 | 40 | $13 |
| Apr | 60 | 30 | $11 | 100 | 40 | $13 |
| May | 50 | 40 | $11 | 110 | 50 | $15 |
| Jun | 40 | 30 | $10 | 100 | 50 | $14 |
| Jul | 40 | 40 | $11 | 110 | 50 | $15 |
| Aug | 50 | 40 | $11 | 100 | 50 | $14 |
| Sep | 60 | 40 | $11 | 100 | 40 | $13 |
| Oct | 70 | 30 | $11 | 80 | 40 | $11 |
| Nov | 60 | 30 | $9 | 60 | 30 | $9 |
| Dec | 60 | 30 | $8 | 50 | 30 | $8 |
kWh rounded to the nearest 10 and dollars to the dollar, so a column may not add up to the yearly figure exactly.
What these numbers leave out
- Snow. Our calculator doesn't model snow sitting on the panels. In snowy places, treat the winter figures as a best case.
- Winter shade. The low winter sun casts longer shadows. A building, tree or balcony above yours that doesn't shade the panels in June may shade them in December.
- This winter's weather. The solar data is a typical year built from many years of records, not a forecast. A cloudy winter makes less.
- Winter loads. We assume a steady 150 W all year. If you run more in the daytime in winter, more of the output gets used. Upload your utility's meter file on a result page to use your own hourly use.
See your own months
Your direction, tilt and rate, hour by hour, for a whole year.
Balcony solar in winter: questions
Does balcony solar work in winter?
Yes. Panels make power whenever light reaches them, including on cold days. In our calculator's nine cities, December to February brought in 17%–28% of a railing kit's yearly savings and 15%–23% of a patio kit's. Snow covering the panels and shade from the low sun aren't in these numbers.
How much less does a balcony solar panel make in winter?
It depends on the mount. Tilted 30° on a patio, a kit made 35%–99% as much from December to February as from June to August. Upright on a railing, it made more in winter in eight of nine cities. In Boston, the railing kit made 230 kWh in winter against 130 kWh in summer; the patio kit 210 against 310.
Is a railing or a patio better for winter?
For winter output, the railing: upright panels face the low winter sun more squarely. Over the whole year the patio made more in every city we ran, because it catches far more of the high summer sun. In Boston, the patio saved $146 a year and the railing $123.
Why doesn't more winter output mean more savings?
Winter days are short, so the kit makes its power in a few midday hours, more than a 150 W always-on load can use at once. With no battery and nothing paid for power sent to the grid, our model counts the rest as worth nothing. On a railing, homes used 37%–52% of the kit's winter output but 70%–98% of its summer output.
Does snow stop a balcony solar kit?
Snow covering the panels cuts their output until it slides off or is cleared. Our calculator doesn't model snow cover, so in snowy places treat its winter figures as a best case.
How we calculated this
Every figure is our calculator's own result, run Oct 16, 2026 through the same steps as a result page: NLR PVWatts v8 hourly output for the city, the 800 W inverter limit, a flat 150 W always-on load, and no credit for power sent to the grid, with no battery. The rate is each state's average residential price from EIA (Aug 2025–Jul 2026), the same for every month, so the months compare on output alone. We split the same hourly results into months; the twelve add up to the year on the result page. It's an estimate. Our full method. How direction and tilt change the year as a whole: Railing, patio or fence.
General information, not financial advice.