Quick answer: A modern residential solar panel measures roughly 66–82 inches long, 40–45 inches wide, and 1. 375 watt solar panels represent the sweet spot of solar technology in 2025, offering an optimal balance of power output, cost-effectiveness, and installation flexibility. It belongs to the Hi-MO 4m series, which has many advantages, including the ability to perfectly adapt to different roofs with its modules of 60 cells/66 cells/72 cells. 6 inches thick, weighs 40–55 lb, and produces 350–460 watts. The full size-by-wattage. The Longi 375W LR4-60HPH 375 / MR solar panel is a 375W monocrystalline module and 120 cells (6x20) from the Longi brand, one of the leading manufacturers in the world photovoltaic industry. Panel dimensions: Length 1755mm Width 1038mm Height 35mm Weight 19.