Calculate the row spacing needed to avoid inter-row shading.
Row spacing must clear the shadow cast at the lowest useful sun angle, which occurs near the winter solstice. Steeper tilts cast longer shadows and therefore need wider spacing. There is a direct trade-off between tilt and density: shallower panels fit more rows in the same area, which often yields more total energy per hectare.
Solar Panel Spacing
Spacing = horizontal projection + panel height ÷ tan(winter solar altitude)
Spacing = horizontal projection + panel height ÷ tan(winter solar altitude) Row spacing must clear the shadow cast at the lowest useful sun angle, which occurs near the winter solstice. Steeper tilts cast longer shadows and therefore need wider spacing.
There is a direct trade-off between tilt and density: shallower panels fit more rows in the same area, which often yields more total energy per hectare.
This calculator takes 4 inputs: Panel length along the slope, Tilt angle, Site latitude, Available roof or ground length. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.