Solar output by roof direction
Can you put panels on an east, west or north roof? On a low-pitch roof the loss is smaller than most people think; on a steep roof it grows fast. These numbers come from real weather data for northern Ohio (41.5° N), a typical mid-US latitude.
Yearly sunlight by direction and pitch
South at the same pitch = 100.
| Roof pitch | South | East | West | North |
|---|---|---|---|---|
| 2/12 (10°) | 100 | 88 | 97 | 84 |
| 4/12 (18°) | 100 | 81 | 94 | 73 |
| 6/12 (27°) | 100 | 75 | 92 | 62 |
| 8/12 (34°) | 100 | 71 | 91 | 54 |
| 12/12 (45°) | 100 | 67 | 90 | 46 |
PVGIS 6 (EU JRC, ERA5 2014 to 2024), yearly in-plane irradiation at 41.5° N 82.0° W, no terrain horizon. Energy output follows irradiation closely.
What the table tells you
- Low pitch makes direction matter less. A 2/12 north roof still gets 84 % of a south one. Flat panels don't care about direction at all.
- West beat east here. Afternoons were sunnier than mornings in this data set. It varies by climate, so check your own location.
- Steep north roofs are a poor bet. At 8/12 and above you lose about half.
Winter makes the gap much bigger
| 4/12 roof | South | North | North / South |
|---|---|---|---|
| December | 61 kWh/m² | 24 kWh/m² | 39 % |
| June | 197 kWh/m² | 187 kWh/m² | 95 % |
With net metering the yearly total is what counts. For an off-grid or battery-only system, winter is usually the limit, so north panels help least when you need them most.
Mixed-direction roofs
- Put each roof face on its own MPPT, or at least its own string. Mixing directions in one string costs energy.
- East plus west spreads production across the day, which helps if you use the power as it is made.
Check your own roof
Draw your roof on the satellite map: direction, pitch and shading from nearby trees and buildings go into the annual energy estimate. Free, nothing to install.
Try it free →FAQ
Are north-facing solar panels worth it?
On a low-pitch roof (2/12 to 4/12) they make about 75 to 85 % of a south roof over a year, which can be worth it if panels are cheap. On steep roofs they lose about half, and winter output is much lower.
Is east or west better for solar panels?
It depends on local weather. In the data shown here west was about 15 % better. In places with clear mornings and cloudy afternoons it can be the other way round.
How much do I lose facing southeast or southwest?
In this data set southwest was about the same as due south, and southeast about 10 % lower. Your local morning and afternoon weather decides which side does better.