Talk to a marine engineer about the overhead (equipment, training, emergency procedures, etc.) of adding a small-scale solar plant to all the things that they've already got to deal with on a ship.
And recall that this bridge - https://en.wikipedia.org/wiki/Francis_Scott_Key_Bridge_(Balt... - will need a multi-billion dollar replacement, because the tiny engineering staff of a huge freighter could not diagnose and correct a surprise electrical failure. Within the maybe 3 1/2 minutes between the initial fault, and when the collision became physically inevitable.
> The surface area of a standard car simply isn’t big enough to hold the sheer volume of solar panels that would be needed to capture a meaningful amount of energy from the sun.
Do you have solar panels on top of your head? If not why do you leave that space unused? Space being there is one of the worst possible reasons. That bloats designs and makes them expensive to build and maintain.