After decades of attempts to power cars with energy from the sun, the solar automotive age might finally be upon us.

Why it matters: With climate change accelerating and high gas prices squeezing consumers' budgets, the notion of filling up with free, clean solar energy is certainly enticing.

The catch: The amount of solar energy that can actually be captured by solar panels on a car's roof is limited, which is why the tech has yet to take off.

What's new: Germany’s Sono Motors, which went public on the Nasdaq last year, may have cracked the code with a $25,000 electric SUV called the Sion that's covered pretty much bumper to bumper in solar cells.

• Instead of a solar glass roof, the Sion's 456 cells are integrated seamlessly into its plastic hood, fenders, sides, roof and rear panels.
• Together, they provide enough energy to extend the car's 190-mile battery range by an average of 70 miles a week — or up to 150 miles per week in perfect conditions.
• For people with short commutes in sunny locales, that could mean never plugging in again.

Driving the news: I checked out the Sion on a recent blustery, overcast day in Detroit during a stop on the car's first U.S. tour.

• The conditions were a good reminder of the car's practical limitations. Sono says the sun can account for about 5,400 miles of range per year — about one-third most drivers' yearly average — but that all depends on the season, the weather and even how shady your parking spot is.

Details: From a distance, the Sion appears to have one of those trendy black matte paint jobs. Up close, however, you can see the rows of solar cells embedded in the car's body panels.

How it works: Sono spent five years trying to perfect its patented injection molding process, which integrates monocrystalline silicon cells into the Sion's scratch-resistant, dent-proof polymer panels.

• Depending on the time of day and the angle of the sun, different parts of the car capture the sun's energy and feed it to the Sion's 54-kWh lithium-ion phosphate battery.
• Solar aside, the Sion's battery can charge in about 30 minutes when plugged into a DC fast charger, or in a few hours at an ordinary Level 2 charger.
• Even without solar power, the $25,000 Sion is an affordable EV (although it won't qualify for U.S. tax incentives because it's built in Europe).

Sono kept costs low by outsourcing production to Valmet Automotive, a well-known Finnish contract manufacturer — and it only comes in one style, with no optional features.

• "You can have any color you want, as long as it's black," quipped chief operating officer Thomas Hausch, paraphrasing Henry Ford's famous comment about the Model T.
• And the company will sell its cars directly to consumers instead of through dealerships.

What they're saying: "They've found, in between the cracks, an opportunity that other automakers were not going after," said Wedbush Securities analyst Daniel Ives.

Be smart: A small handful of other companies, including the California-based Aptera and Dutch startup Lightyear, are also trying to crack the solar-powered EV nut.

What to watch: More than 20,000 Europeans have put down a $2,000 refundable deposit, Sono says, and it has another 22,000 orders from fleet customers, including a subscription car service called FINN.

• The company says it is "actively evaluating American partnership opportunities" to bring the car stateside.
• Meanwhile, it's already generating revenue from selling solar retrofit kits for heavy trucks and buses.