howmuchsun

Solar panel angle in Bulawayo

In Bulawayo, fixed panels collect the most energy over a year tilted 19° from horizontal and facing north. But anything between 10° and 30° is within 2% of the best, so the pitch you already have is probably fine.

What is your roof worth?

Of the maximum 99% facing north, 30° pitch
Best here 19° facing north
Good-enough range 10–30° within 2% of the maximum

Every roof, scored

Percentage of the maximum possible annual yield, for each combination of orientation and pitch in Bulawayo.

Percentage of maximum annual yield by roof orientation (rows) and pitch (columns).
Roof faces 15° 30° 45° 60° 90°
North 95% 100% 99% 92% 80% 47%
North-east / north-west 95% 98% 96% 89% 79% 53%
East / west 95% 93% 88% 80% 71% 51%
South-east / south-west 95% 88% 77% 65% 52% 34%
South 95% 86% 71% 54% 40% 20%

Where "tilt equals your latitude" happens to work

The rule of thumb says tilt your panels at your latitude — 20° for Bulawayo. The real optimum is 19°, so here the rule happens to be about right.

The rule breaks down further from the equator, where the optimum falls increasingly below the latitude — by around 10 degrees at 50°, and 15 by 65°. Close to the equator the two happen to coincide, so here the rule of thumb is genuinely fine.

Seasonal angles

If you can adjust your panels twice a year, these are the angles to use. Most people should not bother — the gain is small and the ladder is real.

SettingTiltFacing
Fixed, all year19°north
Summernorth
Winter46°north
Flat on the ground

A flat installation here keeps 95% of the maximum; mounted vertically on a wall, 47%.

Other cities in Zimbabwe

Assumptions

  • These are angles and percentages, never kilowatt-hours. Optimal angles are driven by geometry and are robust. Absolute energy output depends on measured irradiance, cloud, soiling and hardware, none of which are modelled here.
  • Clear sky, no shading. Trees, chimneys, neighbouring buildings and terrain are ignored, and they can dominate everything on this page.
  • Fixed panels. Trackers follow the sun and change the answer entirely.
  • Ordinary ground. Reflectance is taken as 0.2, typical for grass and soil. Snow reflects far more and favours steeper tilts.

Full methodology, sources and known limitations