A roof only needs to be a thin piece of sheet metal, weighing somewhere in the neighborhood of 1-2lbs per square foot
Most solar panels are going to weigh somewhere in the neighborhood of 2-4lbs per square foot. So is likely the panel would weigh 2-4 times as much as just a plain metal roof, plus possibly a metal roof under it and/or additional framing to attach the panels to, so power to weight does absolutely come into play.
That comes in at an additional 400lbs on a vehicle that weighs 6,670 lbs if you assume the maximal weight of the panels and the need for a metal roof anyways. That extra 6% weight just doesn’t matter. 6% losses range for 12% free charging seems like a worthy tradeoff to me. (and again, this is the maximal value).
That extra 6% weight just doesn’t matter.
LOL weight is incredibly important. Automakers would kill puppies for a 6% weight reduction.
6% weight increase doesn’t necessarily mean a 6% efficiency loss, it’s not a simple linear relationship like that. Depending on the power of the motor and a few other factors that 6% weight increase could mean a huge hit to efficiency.
