Quick answer: A modern residential solar panel measures roughly 66–82 inches long, 40–45 inches wide, and 1. 6 inches thick, weighs 40–55 lb, and produces 350–460 watts. The full size-by-wattage. Standard Residential Panels Optimize Space and Handling: The industry-standard 60-cell panel dimensions (65″ × 39″ × 1. 5″) aren't arbitrary – they represent the optimal balance between power output, installation ease, and roof space utilization. The exact solar panel size depends on wattage, cell type, frame design, and manufacturer. Some are ultra-efficient and compact; others are larger but deliver less per square metre.