ELI5: Why aren’t electric vehicles using solar panels integrated into the panoramic rooftops? Wouldn’t this eliminate the need for charging stations – to be able to collect a solar charge at most hours of the day and *during* the actual act of driving?

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The Hyundai Sonata hybrid (gasoline-electric hybrid, no plug) has this exact feature. With six hours of sunlight, it can generate about two extra miles of range per day. The solar panels aren’t strong enough, and some of the electricity generated is lost immediately because the car is heavier.


They don’t deliver nearly the power required. A meter squared of solar panel delivers about 1 kW under peak conditions. Let’s assume you can fit a square meter of solar panels on your car. A chevy bolt with a 66 kWh battery would take 66 hours of peak sunlight. A Tesla Model S takes 100 hours. Meaning you’re probably losing more energy due to the added weight of the panels than you’d ever get by charging. This is why “why don’t we put solar panels on <x>” pretty much never works unless <x> is something big and static like a building.


Very basically, the energy captured by solar panels is…not really enough for a car. Panels will often operate at poor efficiency in many driving conditions. The panels themselves will be pretty costly and it’s also very likely that having them travel consistently at high speeds would lead to wear and tear, adding to repair costs. Unlike other sources of “free” energy a car could make use of, like that captured by regenerative breaking, the energy of the sun hitting the car is just too expensive and cumbersome to make use of.


Electric cars use a lot of energy compared to how much you can get out of solar panels: A solar panel can only put out about 20 Watts of power per square foot, and that’s only in direct sunlight. The current Tesla Model 3 has a 62,000 Watt-hour battery. Let’s assume you could fit 65 square feet of solar panels onto the hood, roof and trunk of a Tesla Model 3. 62000 Wh ÷ (20 W/sq.ft × 65 sq.ft) ≈ 48 h So it would take 48 hours to fully charge the car’s battery. That doesn’t sound ***too*** bad, right? Just two days? ***Nope.*** 48 hours ***of peak sunlight.*** Most of the US only gets about 4 hours of peak sunlight per day, so it would take more than a week. Probably more like 2 weeks when you account for bad weather.


They exist, but not in a state where regular comsumers can buy them, check out the world solar challenge its a race for solar vehicles that crosses australia.