howmuchsun

Solar panel angle in Rostov-on-Don

In Rostov-on-Don, fixed panels collect the most energy over a year tilted 39° from horizontal and facing south. But anything between 30° and 50° 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 south, 30° pitch
Best here 39° facing south
Good-enough range 30–50° within 2% of the maximum

Every roof, scored

Percentage of the maximum possible annual yield, for each combination of orientation and pitch in Rostov-on-Don.

Percentage of maximum annual yield by roof orientation (rows) and pitch (columns).
Roof faces 15° 30° 45° 60° 90°
South 82% 93% 99% 100% 95% 71%
South-east / south-west 82% 89% 93% 92% 86% 66%
East / west 82% 80% 76% 71% 65% 49%
North-east / north-west 82% 71% 58% 47% 39% 29%
North 82% 66% 50% 36% 26% 19%

Why "tilt equals your latitude" is wrong here

The rule of thumb says tilt your panels at your latitude — 47° for Rostov-on-Don. The real optimum is 39°, 8° lower than the rule suggests.

Two reasons, both geometric. Summer days are much longer than winter ones, so the year's energy is weighted toward a higher sun than the annual average. And a low winter sun sends its light through a long slant of atmosphere, arriving weak — tilting to catch it costs more in summer than it wins in winter.

In fairness to the rule: following it here would cost you only 0.8%. It is wrong, but it is not expensive.

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 year39°south
Summer19°south
Winter67°south
Flat on the ground

A flat installation here keeps 82% of the maximum; mounted vertically on a wall, 71%.

Other cities in Russia

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