Key takeaways
- South-facing, tilted 25–40° produces the most energy over a year in the US.
- East or west costs about 18%; vertical railing mounting about 30%.
- Vertical panels do relatively well in winter and badly in summer.
- Shade is the biggest enemy — even a strip of shade can cut output sharply.
- On time-of-use rates, west-facing panels can be worth more than south-facing ones.
On a rooftop, installers choose the ideal angle. On a balcony, you take what you get: a railing that faces one direction, a floor above you that casts shade, and limited options for tilting. Knowing how much each factor costs helps you decide whether — and how — to install.
The short answer
| Setup | Annual output vs. ideal |
|---|---|
| South, tilted 25–40° | 100% |
| South-east / south-west, tilted | ~95% |
| South, flat (0–10°) | ~88% |
| East or west, tilted | ~82% |
| South, vertical (railing) | ~70% |
| North, tilted | ~58% |
These are the planning factors we use in our calculator and methodology. Exact figures vary with latitude and climate; NREL's PVWatts tool can model your exact location.
Direction
In the Northern Hemisphere, the sun is due south at midday, so south-facing panels collect the most energy. Moving away from south costs relatively little at first and more as you approach east or west:
- South-east or south-west: about 5% less. Barely noticeable.
- East or west: about 18% less over a year.
- North: typically not worth it.
East vs. west
Total output is similar. The difference is when you produce:
- East produces in the morning — good if your household is busy before work.
- West produces into the late afternoon — better for evening households and for time-of-use rates, where 4–9 pm power is the most expensive. On many California TOU plans, a west-facing kit can save more money than a south-facing one despite producing less energy.
Two directions at once
If you have a corner balcony, splitting panels between two directions (say, one east and one south) flattens production across the day. That increases self-consumption — you use more of what you make — which matters because plug-in systems aren't net-metered. A microinverter with independent inputs per panel handles this well.
Angle
The ideal fixed tilt for annual production in the continental US is roughly equal to your latitude minus a few degrees — about 25–40°.
- Vertical (90°), the default on most balcony railings, loses about 30% over a year. But it's not uniform: vertical panels catch the low winter sun well and lose most in summer, when the sun is high. In northern states with snowy winters, vertical has the bonus of shedding snow.
- Flat (0–10°) loses about 12%, mostly in winter, and collects more dirt.
- Tilt brackets that angle railing-mounted panels outward by 20–40° are one of the best upgrades you can buy. Check that your building allows it and that the hardware is wind-rated.
Shade: the biggest factor of all
Solar cells in a panel are wired in series, like old holiday lights. Shading part of a panel — a strip from the balcony above, a railing bar, a tree branch — can reduce that panel's output far more than the shaded area suggests. Bypass diodes and half-cut cell designs reduce the effect but don't eliminate it.
How to assess your shade:
- Watch your balcony on a sunny day: note when direct sun arrives and leaves.
- Mind the seasons: the winter sun is much lower, so a balcony that's sunny in June may be shaded by buildings across the street in December — and vice versa for the balcony above you.
- Use a sun-path app to see the sun's track at your location through the year.
As a rule of thumb, you want at least 4–5 hours of direct sun around midday for plug-in solar to make financial sense.
Getting more from a small balcony
- Tilt the panels outward if allowed.
- Mount high on the railing to clear shadows from the balcony floor and railing.
- Use a microinverter with independent inputs so one shaded panel doesn't drag down the other.
- Choose higher-efficiency panels when space is the constraint.
- Keep panels clean — dust and pollen in dry climates can cost several percent.
- Consider the wall: a sunny wall or fence below your window may outperform a shaded balcony.
Worked example
A renter in New Jersey (25.19¢/kWh, about 4.3 sun hours) with an 800 W kit:
| Setup | Saved per year |
|---|---|
| South, tilted 30° | ~$218 |
| South, vertical railing | ~$152 |
| West, tilted 30° | ~$179 |
| West, vertical railing | ~$125 |
The difference between the best and worst realistic setup is nearly $100 a year — more than the cost of a good tilt bracket. Try your own balcony in the calculator.
Frequently asked questions
What is the best angle for balcony solar panels?
For maximum annual output in the continental US, roughly 25–40° from horizontal, facing south. A steeper angle (45–60°) favors winter production and helps shed snow; a flatter angle favors summer.
Is a north-facing balcony worth it for solar?
Usually not. North-facing panels in the US produce roughly 40% less than south-facing ones even when tilted shallowly, and vertical north-facing panels receive almost no direct sun. Unless your electricity is very expensive, the payback is poor.
Should balcony solar panels face east or west?
They produce about the same total energy. West is usually better if you're on a time-of-use rate with expensive late afternoons, or if you're home in the evening. East suits households that use more power in the morning.
How much does shade affect balcony solar?
A lot. Shading even part of a panel can reduce that panel's output disproportionately, because cells are wired in series. Microinverters with separate inputs per panel limit the damage to the shaded panel.