Latitude rule of thumb4 min read

Worked Example: Fixed Tilt Angle for a Site at 24.5° Latitude

Year-round, winter-biased and summer-biased tilt angles for a site in the Gulf region, and when the rule of thumb is good enough.

Open Solar Panel Tilt Angle calculator

Scenario

Site latitude	24.5° N
Mounting	Fixed tilt, facing due south

Step-by-step calculation

Step 1: Year-round tilt

β ≈ latitude

β ≈ 24.5°

β = 24.5°

Step 2: Winter-biased tilt

β ≈ latitude + 15°

β ≈ 24.5 + 15

β = 39.5°

Step 3: Summer-biased tilt

β ≈ latitude − 15°

β ≈ 24.5 − 15

β = 9.5°

Step 4: Practical adjustments

In dusty climates a slightly steeper tilt helps rain and cleaning remove soiling, and very low tilts (below about 10°) hold dust and water. On large ground-mounted plants the tilt is usually set by an energy-yield simulation that also accounts for row spacing and shading.

Result summary

Check	Requirement	Actual	Status
Year-round tilt	≈ latitude	24.5°	✓ PASS
Winter / summer bias	latitude ± 15°	39.5° / 9.5°	✓ PASS

For year-round production at 24.5° latitude, tilt the modules at about 24.5° facing south. Use about 39.5° to favour winter output or 9.5° to favour summer output.

Key insight: Near the optimum the yield curve is flat: a few degrees either side changes annual energy by only around 1%, so structural, wind-load and cleaning considerations can decide the final angle.