Electric Vehicles

I wonder how much energy is in a liter of sunshine.

Photovoltaic panels capture energy from the photons that hit it, at a finite speed of light.

At Earth's distance from the sun, solar radiation is about 1450 W/m^2 . Each watt is 1 joule/second. And a liter, which is 1000 cubic centimeters, would basically represent a volume that is the 0.1cm of space above a 1 square meter panel (100 cm x 100 cm x 0.1 cm = 1000 cubic centimeters).

So how much energy hits a 1 square meter panel in the time it takes for light to travel 0.1 cm? Light travels at 3.0 x 10^8 m/s, or 3.0 x 10^10 cm/s, so we're talking about the light that hits a panel over the course of about 3.3 x 10^-12 s. At 1450 joules per second, times 3.3 x 10^-12 s, we get 4.83 x 10^-9 joules.

4.8 nanojoules in a liter of sunshine. That's way less than a liter of gasoline/petrol!

Then again, using a solar panel you're able to capture a column of light 3.0 x 10^8 meters tall using that 1 square meter panel. So you're catching 3.0 x 10^11 liters per second worth of sunlight, which makes the relative low energy per liter still add up to a lot.