Solan panels on vehicles sounds like a great idea but the physics makes it a stupid gimmick.
You also have to clean them constantly in this application, I imagine.
I guess they could make some kind of windshield wiper for the solar panels.
How so? Is it that they aren’t efficient enough to be worth the materials it’s made from?
Power to weight ratio favors permanent fixed installations. A car roof is far too small to make a useful amount of energy.
Power to weight doesn’t matter as we are talking about using a solar panel instead of a roof. There’s no added weight. The car will already have inbuilt inverters so the only real weight add is the wiring. But also, this is a postal vehicle which will have large swings in weight anyways. A couple of extra pounds doesn’t make a difference here.
Further, this isn’t a car, which has a much smaller surface area. These things have about 10 square meters of flat roof. That’s a peak output of ~3kW. (realistically, probably closer to 1.5kW average throughout a day) which translates into 12kWh of charge in any given day. Roughly 10% of the battery capacity could be restored daily.
For large vehicles, like delivery vehicles and busses, the math on making the roof out solar panels instead of steel changes.
It’s cheaper to put a light roof on a car, buy the same area of solar cells, set them up to charge a battery, and charge the car off that battery, than it is to buy a custom, toughened, solar cell the area of the roof.
Plus, you don’t have to haul around the extra weight at the worst location for weight in a vehicle.