Minimum row spacing for solar panels, critical to prevent shading, is typically 2–3 meters in mid-latitudes (e., 40°N), calculated using winter solstice sun angle to maintain 90%+ energy output, with fixed-tilt systems often at 1. 5x panel height for optimal performance. However, it is worth remembering that to determine the minimum distance between the rows, we only need to know the minimum angle of incidence of sunlight during the year, which occurs during the winter solstice (December 22), when the sun is at its zenith over the Tropic of Capricorn. Solar altitude depends on latitude, tilt, and solar declination for the selected date. The spacing between. Solar Design Calculator: Calculate minimum row spacing to eliminate inter-row shading for ground-mount and rooftop solar arrays.