The surface area of a car is modest and PV adds just a few miles of range per day.

A solar system adds weight, electronics, and complexity.

PV only produces power if the car is in the sun — and then the hot car needs to be cooled. With AC.

A solar panel, contoured and ruggedized for a car roof, is an expensive and difficult-to-repair way to make power.

Even 2017 Elon Musk agreed when he said, “The least efficient place to put solar is on the car.”

Solar powered Cybertruck

But 2019 Elon Musk disagreed and added an (as-yet-unpriced) option to the 2021 Tesla Cybertruck that “generates 15 miles per day, possibly more” from solar power. Musk’s tweet said, “Adding fold out solar wings would generate 30 to 40 miles per day. Avg miles per day in US is 30.”

At best, one might conclude that the panels add a few miles per day, power a fan and help when camping.

That was before the virus. Now, every socially-distanced mile of vehicle range is crucial when making weekly grocery, chocolate, liquor and medical supply runs.

Solar on a truck is a “game changer” and “killer app?”

Electrek, not always an unbiased arbiter, believes that the Cybertruck solar option is “a game-changer” and Tesla’s new “killer app.” Electrek suggested that Tesla would “leverage its experience with the solar roof to introduce it to other cars.”

Other vehicle builders are toying with the integrated solar car roof.

Last year Hyundai launched a Sonata Hybrid with a solar roof charging system that could provide an extra two miles of range per day.

According to Dutch startup Light Year, the roof and hood of its prototype is made of 50 square-feet of solar cells within safety glass. The company is claiming a range of 450 miles and the ability of its PV array to add 7.5 miles of range per hour when in the sun.

Sion, built by German startup Sono Motors, is a solar-integrated EV with a 155-mile range.