Eli5 Solar panels on airplanes



Why aren’t there solar panels on airplanes? Can we do that? If not why?

In: Engineering

It takes a lot of potential energy to get from 0 to flying. The amount of energy you would get from a solar panel would not be enough to get you off the ground. You would need a lot of stored energy which we get from the fuel. Now whether solar panels will become way more efficient and electric planes will become a thing. Sure. But with the current technology it makes a lot more sense to use chemical fuel to get a plane in the air.

We could, but the extra weight would use more fuel-energy than the solar panels would produce, so it’s a net detriment to efficiency.

There have been a few light weight, ultra efficient drone type projects done with solar panels, but it just doesn’t scale well.

The amount of energy you could harvest from a moving vehicle is extremely negligible to the amount of energy it took to make the panels, install, added weight etc etc in the first place. Also why you haven’t seen them on cars.

Energy density is low that’s why utility scale solar plants are vast (huge area) so energy harvest becomes significant by increasing system size to encompass such large areas. On a plane, we’d be talking about energy harvest of a few hundred watts or low thousands of watts in peak sun even if major sections of the plane were covered in photovoltaic material. Of course energy harvest would be zero at night and just barely more than that when available solar energy was minimal (cloudy weather, etc.).

Jet fuel is tremendously energy dense (9.6 Kwh/liter).