Grade A panels have no defects, 100% power compliance, and come with a 25-year original factory warranty; Grade B panels often have scratches or color differences, the power is usually 3-5% lower, and there is no official warranty. Solar panels are graded based on cell quality, manufacturing consistency, defect levels, and aesthetic appearance. Let's break them down: These are. Differences between Class A and Class B photovoltaic panels: Color: The color within a group of Class A panels is consistent, while Class B panels are allowed to have slight color differences within the same group. V-shaped: Not allowed for Class A. Both get you from point A to B, but with different perks. Here's how they stack up: Efficiency Showdown: A Panels typically deliver 19-21% conversion rates, while B Panels push 17-19% (NREL 2024 data).