Panel Direction (Azimuth)
Panel direction has the biggest impact on energy production. Here are typical values (relative to 100% for optimal south-facing):
| Direction | Relative Yield | Rating |
|---|---|---|
| South (0°) | 100% | Optimal |
| Southeast / Southwest (-45°/+45°) | 95-98% | Excellent |
| East / West (-90°/+90°) | 80-85% | Good |
| Northeast / Northwest (-135°/+135°) | 60-70% | Acceptable |
| North (180°) | 40-50% | Not Recommended |
Tilt Angle (Panel Inclination)
The optimal tilt angle depends on your location's latitude and panel direction:
- South-facing: Optimal tilt equals your latitude (30-40° for most US), or 20-30° for balcony mounting
- East/West-facing: Optimal 20-30° (flatter is better for morning/evening sun)
- North-facing: 60-90° (steeper angle to catch more light, but still not recommended)
For Balconies: Typically 0-30° tilt. Flatter angle (10-20°) works better for East/West, steeper (25-30°) for South. Most balcony mounting systems allow 15-25° adjustment.
Shading – The Biggest Energy Killer
Shading dramatically reduces energy production. Even 10% shading can cause 20-30% energy loss:
| Shading | Energy Loss | Rating |
|---|---|---|
| 0-5% | 0-5% | Acceptable |
| 5-15% | 10-25% | Still OK |
| 15-30% | 25-50% | Problematic |
| >30% | >50% | Not Recommended |
Common Shading Sources
- Neighboring Buildings: Morning (East) or evening (West) shadows
- Trees: Especially in spring/summer when leaves are full
- Balcony Railings: When panels are mounted too low
- Roof Overhangs: For roof-mounted systems
- Vent Pipes & Antennas: On rooftops
North-Facing Balcony – Is It Worth It?
Short Answer: Usually not, except under very favorable conditions.
With north-facing orientation, you'll only get 40-50% of optimal energy production. An 800W system would produce like a 320-400W system. The payback period becomes very long (15+ years), making it rarely cost-effective unless electricity rates are very high or you have no other option.
Best Practices for Maximum Production
- Choose South if possible: Even 5-10° off south still gives 98-99% of optimal
- East/West can work well: Especially if you use more energy in morning (East) or evening (West)
- Minimize shading: Check for shadows at different times of day and seasons
- Adjust tilt seasonally: If possible, steeper in winter, flatter in summer
- Consider microinverters: Better performance with partial shading than string inverters