About the Module Layout Planner
Module layout planning determines the optimal arrangement of solar panels on a rooftop or ground-mount site — deciding row orientation, number of panels per row, row spacing, and grouping into strings — to maximise capacity, minimise shading, and produce a clean string configuration for the inverter.
How to calculate it
- 1Map the available area: draw the roof or plot boundary, mark all obstacles (water tanks, lift rooms, AC units, trees, chimneys) and exclusion zones (fire access, setbacks).
- 2Choose orientation: portrait (panel long-axis vertical) or landscape (long-axis horizontal). Portrait gives more rows in a given height; landscape gives fewer taller rows.
- 3Determine row direction: east-west rows (panels face south, rows run along the east-west axis) is standard. East-west bifacial mounting (panels tilted east-west on a flat roof) is increasingly used to spread generation more evenly through the day.
- 4Calculate number of rows and panels per row from the available dimensions, row pitch, and panel size.
- 5Group panels into strings: each string has the same number of panels (to match MPPT voltage windows). Aim for equal string lengths — unequal strings reduce MPPT efficiency.
- 6Verify string voltage range: sum of panel Voc at minimum temperature must not exceed inverter maximum DC input voltage.
Worked example
A 600 m² rectangular terrace (20 m × 30 m). After 1 m perimeter setback: usable 18 m × 28 m = 504 m². Panel: 2.1 m × 1.05 m (portrait), 440 W. Row pitch at 15° tilt: 3.2 m (for < 2% shading loss at 9 AM winter solstice). Rows in 18 m dimension: ⌊18 ÷ 3.2⌋ = 5 rows. Panels per row: ⌊28 ÷ 1.05⌋ = 26. Total: 5 × 26 = 130 panels × 440 W = 57.2 kWp.
What you can calculate
- Portrait/Landscape
- 1P / 2P tables
- String count
- Table & row count
Frequently asked questions
Portrait or landscape — which orientation is better for solar panels?
On flat rooftops with east-west rows: portrait orientation gives more rows in the available north-south depth, so it fits more capacity in the same area. On sloped roofs: landscape usually follows the roof rafter direction and is structurally simpler. For bifacial east-west installations (panels tilted alternately east and west at 10–15°): landscape is standard. There is no yield difference between portrait and landscape — it only affects how many panels fit in the space.
What is an east-west bifacial solar installation?
In an east-west bifacial layout, panels are mounted in alternating pairs — one tilted east, one tilted west, at 10–15° — like a continuous sawtooth roof. Each panel's front face generates in its primary direction (morning or afternoon) while the rear face captures diffuse light. This layout has no inter-row shading (rows are only 0.5–0.8 m apart), dramatically increasing capacity per m² (up to 2× traditional south-facing layouts), and spreads generation from morning to evening — ideal for high self-consumption users.
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