As population rises, fossil fuels will start depleting so are solar powered cars a good idea? How much power can they produce when it is cloudy?

  • Can you be a bit more specific? Are you referring to cars with built-in solar panels? Or battery electric vehicles charged by separate solar panels (such as a parking garage with solar panels)?
    – LShaver
    Nov 15, 2019 at 14:51
  • I mean a car with solar panels on the roof and on the body of the car. Nov 16, 2019 at 1:01
  • There is a Dutch company called Lightyear that is building an all-electric solar passenger car. It can be charged like a normal electric car and the solar panels extend the driving range by adding 12 km/h during daylight exposure. The price is very steep though; you can pre-order it at $135,000
    – THelper
    Nov 16, 2019 at 10:38
  • I would expect a solar car to weigh about 300 pounds, have one seat, and have a battery in addition to the solar panel. solarcar.njit.edu . Compare to a Renault Twizy at 1000 pounds weight including a 220 pound battery. Well the Twizy could tow a trailer carrying a solar panel.en.wikipedia.org/wiki/Renault_Twizy
    – S Spring
    Nov 16, 2019 at 18:54

1 Answer 1


A self-contained solar-powered car is not viable. There simply isn't enough area for the solar panels.

Take a Honda Civic as an example: it's got about eight square meters of top surface that solar panels could be installed on, for a peak theoretical generation of 8 kW. That same Honda Civic has a 92-kW engine, meaning that for each second of maximum power output, the car requires eleven and a half seconds of charging under ideal conditions.

Things look even worse once real-world constraints are factored in. The best solar cells ever built are only 47% efficient. Streamlining the car requires tilting the front and rear windscreens rather than leaving them vertical, which reduces the available panel area. The panels are rarely oriented square-on to the Sun. Solar panel output drops by about 20% over the useful life of the panel. All this adds up to an actual average power output of around 2.2 kW, or 42 seconds of charging per second of peak output.

Looking at it another way, one liter of gasoline has about 9.7 kWh of energy; an automobile engine can convert that into about 2.9 kWh of useful output. A solar Civic would need to spend 62 hours in direct sunlight to get the equivalent of a full tank of gas.

  • They aren't cars, but I think there is at least one solar power bus already in operation, and at least one RV! Dec 23, 2020 at 21:17

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