Shifting Gears: Driving with the Sun

Installing a wind powered generator in front in addition to rooftop solar cells will enhance the charging of EV.

A windmill-powered generator in front will cause an increase of X in the energy to move the car (due to aerodynamic drag) and will net (at very best) .5X in recuperated energy. Thus an onboard windmill decreases the range of an EV, if the windmill is used while the car is moving.

(If this windmill is used only when the car is stopped, then it can help charge the car, without causing a loss in the car's efficiency. However the weight and cost of the windmill carried around all the time, but used only infrequently become issues. )

A windmill that popped up on command (from a fully retracted streamlined position) could be used for regenerative braking -- to cause drag, to slow the car. A small portion of the energy absorbed by the windmill could be returned to the batteries. However, modern EVs already have regenerative braking which operates at much higher efficiencies (typically twice the efficiency you'd expect from a windmill), by using the drive motor as a generator (something it naturally does -- so implementation of regen adds essentially no weight at all).

Solar panels, however, if they are installed in such a way as to not adversely effect aerodynamics, can help charge the car's batteries. They have a very small effect, however: covering the entire upper surface of a car can extend battery range by several miles, but at great cost. (Solar racers can actually get all their energy from sunlight, but everything is sacrificed to do so: they are unsafe, and uncomfortable, and have a very large footprint relative to the size of the single person carried... but demonstrate what can be done, and are pretty cool in that sense.)

Today, and for the next decade or more, it's far better to mount the panels at the house, use a grid tie inverter, and sell the power to the utility company at a relatively high peak daytime rate, and buy it back at lower nighttime rates. The utility likes it because it helps provide peak capacity, without capital outlay. The car owner likes it because the electricity for car charging becomes even cheaper: 5 cents per kilowatt hour in some states. Environmentally concerned people like it because it means that less fuel is burned to produce electricity.

_{(Pssst, I think he was kidding)}

In 1980s somebody was given a UK patent but I don't have the details now.