This Is Why We Don't Have Solar-Powered Autos

Jun 10, 2021 04:11 PM ET
  • The suggestion of humming about on pure sunshine appears compelling. The sun certainly gives off enough energy, yet math discloses that it's much less useful than it seems.

The sun is the closest thing we've discovered to an infinite source of energy. It pesters the Planet with sufficient energy to power a year's well worth of human electric activity in just over a hr. It won't run out for billions of years, it doesn't pollute our atmosphere, and it can be accessed from anywhere. You would certainly be forgiven for assuming it's the perfect service to powering our cars.

In spite of that, as business pour billions right into electrification as well as hydrogen, none have introduced a solar-powered car. The factor is easy math. As Design Explained spells out in his new video clip, there are limitations to how much energy can be caught by a car-sized solar panel.

Taking the complete amount of energy the Planet receives from the sunlight, you can find a typical per square meter. Utilizing that average, you'll discover that a Tesla-Model-3-sized solar panel can theoretically get 12 kW-- equivalent to 16 hp-- directly from the sun. That's enough power to maintain a Design 3 humming along at 62 mph without ever requiring to bill.

But the real life isn't that glowing. In between the sunshine reflected by and soaked up by the environment, only regarding 55 percent of the power received by the Earth makes it to the ground. And also, that just occurs throughout the day. Peak power is just offered at regional noon, with off-angle sunshine restricting your power collecting in the early morning and night.

Then there are the technological limits. Even if we could make a single-panel solar efficient in harvesting power with the optimum efficiency in theory feasible, it would certainly still only turn about 33.7 percent of the captured solar power right into functional electricity. The car, as well, requires windows and also various other non-solar surfaces that reduce overall power input. Combined with the losses in charge effectiveness as well as motor effectiveness, you end up only obtaining sufficient energy to continuously go for 12 mph (not including the energy required to speed up, which is greater than preserving a continuous rate.).

Leave the auto sitting still and also you can develop that power book. It simply will not happen rapidly. With cloudless skies, it would certainly take 200 hrs (8.3 days) to totally charge a Tesla Model 3's 75-kWh battery. With excellent solar panels and also ideal climate, that's still a quite incomplete outcome.