To find the best solar panels, we analyzed thousands of models from hundreds of manufacturers featured on the EnergySage Marketplace. We compared key factors like efficiency, power output, performance in warmer temperatures, and warranty coverage. Five brands stood out: Maxeon, VSUN, REC, Qcells. Solar panel efficiency is the amount of sunlight (solar irradiance) that falls on the surface of a solar panel and is converted into electricity. Due to the many advances in photovoltaic technology over the last decade, the average panel conversion efficiency has increased from 15% to over 24%.