PV Inter-Row Spacing and Ground-Coverage Ratio

The row pitch is the panel's horizontal footprint plus the shadow its top edge throws at the minimum winter-design sun angle, and the ground-coverage ratio (collector length over pitch) drives both the land area and the inter-row shading. Pack the rows tight for more kilowatts on the lot, or spread them for clean panels - a shallow tilt throws a far shorter shadow and packs nearly 50 percent more array on the same field. The profile angle is the winter sun elevation from latitude or solar-times. A layout geometry, not an annual shading-loss model.

rise = L x sin(tilt); base = L x cos(tilt); shadow = rise / tan(profile_angle); pitch = base + shadow; gap = shadow; gcr = L / pitch.

NREL / Sandia PV array row-spacing geometry (pitch = L x cos(tilt) + L x sin(tilt) / tan(profile_angle), GCR = L / pitch), by name; the relations are first-principles trigonometry.

The row-spacing geometry and the ground-coverage-ratio definition are public NREL / Sandia relations and first-principles trigonometry.

Estimate. AHJ and licensed professional govern.

Field names used by the API: module_length_ft, tilt_deg, profile_angle_deg, rise_ft, base_ft, shadow_ft, pitch_ft, gcr

• Row pitch pitch = collector horizontal footprint + the shadow its top edge throws at the minimum profile angleNREL / Sandia
• Profile angle the winter-design sun elevation; a profile angle near the horizon throws an effectively infinite shadowfirst principles
• Ground-coverage ratio GCR = collector length / pitch drives both the land area and the inter-row shadingfirst principles