“Not enough surface area to generate any significant energy compared to typical vehicle use.”
Using the newest super efficient (34%) solar cells, and plastering the whole top surface and most of the rear window/hatch, they seem to be getting into the low end of the ball park. Not a standalone power source for a real general purpose vehicle, but possibly for a short haul urban commuter vehicle (or golf cart), or to run A/C and a TV/computer for many hours at a halt.
“The solar module with an 860 Watts output enough to power a small microwave could add 44.5 km, or some 28 miles, to the pure-electric range of the car. What’s more, the new module provides solar power also when the car is driven, resulting in a total sun-provided pure battery range of 56.3 km, or 35 miles. All data as per Toyota’s press release, non-EPA, your solar mileage may differ.
Considering that Toyota rates the pure electric range of a standard-issue Prius PHV at 68 km (42 miles), or 25 mile EPA, the bottom line of this experiment is that with those new solar cells, owners of a plug-in Prius would no longer have to plug in.” (On a fair-weather day).
People claim that they get ~40 mpg in a Prius @ 80 mph [Interstate speed in some States].
A gallon of gas has 33.41 kWh per gallon, so that’s 66.8 kWh to go 80 mi. on the highway. Of course an IC engine is not 100% efficient. At 25% efficiency that’s 16.7 kWh to go 80 mi.
The solar array on this car gets as much as 0.8 kW over 10 hr. That’s 8 kWh so you get to go ~40 mi. out on the highway.
That’s a half hour of driving on a 10 hr. full sun day. So it’s not really close to being able to keep up with actual vehicle energy use.