Since I write about EVs and such, I get this question very often: Why don’t electric cars have solar panels on the roof to charge the battery when the car isn’t being driven (or even when it is)?
It’s a common sense question on the surface, but it’s usually asked from the point of misunderstanding around the realities of EV batteries, solar power basics and how much energy an electric vehicle uses. So here’s the short answer: They don’t because it would take literally months for a small rooftop solar panel to charge an EV battery. Besides that, the nature of the electrical power generated by a small solar panel really isn’t compatible with the needs of an EV battery. It’s a good idea and it seems simple, but technologically, we’re not really there yet. Or are we?
German EV startup Sono Motors is out to prove me wrong (on several fronts) with its Sion EV, which is literally wrapped in solar cells. And they’re looking beyond cars to utilize this same tech to charge up electric trucks and other vehicles.
The key to the $30,000 Sion (not to be confused with the defunct Scion brand of cars from Toyota) is ultimate flexibility when it comes to power. Like all other EVs, the boxy Sion charges primarily from dedicated Level I, II or III (CCS) chargers to energize its 54kWh battery, giving it about 180 miles of range from the single electric motor that makes about 160 horsepower and about 200 pound-feet of torque. If you’re on the hot Level III spigot, the battery will charge up in under an hour. But while it’s just sitting at the shops and not plugged in, sunlight striking the vehicle is also converted to energy from some of the over 456 “half cells” that cover the Sion’s flat external surfaces. At maximum sunniness, those panels can generate about 1.2 kilowatts (or 1,200 Watts) of power for the battery, which equates to the power used by a hair dryer or microwave oven. It’s a fair bit of juice, but far less than that provided by even a Level II car charger, which can provide up to about 40 times more electricity. Put another way, the maximum power the solar cells on the Sion can provide is about what you get out of a wall socket when you plug in your toaster. It’s better than nothing, but it’s still going to take a lot of sunny daylight hours to refill a low battery.
But the thing is, the Sion still makes sense. Most EV owners (self included) don’t run their batteries down close to zero very often (if ever), so the Sion’s solar array can actually tack on a number of miles to the existing driving range while just sitting in the sun. Not hundreds of miles or kilometers per day, but maybe a dozen or so. Sono says the system can add 245km or 152 miles of range per week, which works out to be about 21 miles per day – if we’re talking a 7-day week and you have uninterrupted sunshine (except, of course, at night, unless it’s June above the Arctic Circle, in which case your mileage may vary). If you’re only driving, say, about 40 miles per day on average (and that is the actual average in the U.S.), that could mean half of your energy use for much of your driving is, in essence, both free and completely renewable. The counterpoint is that you have to drive a car covered in solar panels, which would have made you Top Geek at your D&D club not that long ago, but now makes you look like a geek genius to your pickleball teammates.
The Sion is a literal tech powerhouse as well, with Sono saying the car can also provide power for common plug-in electrical items up to 3.7 kilowatts, so you can blend up some epic margs at the tailgate party or power a home during a blackout using V2H two-way charging tech. The Sion also has the capacity to charge other electric vehicles in a pinch. Like I said: It’s flexible.
But Sono Motors is looking well past the Sion and applying the solar panel idea to much bigger vehicles, where it will actually make even more sense. Collecting solar power is all about filling space with panels, and buses, trucks and even trains have a lot more real estate to offer than the top and sides of cars. As more cities phase out diesel buses and even look to ban gas-powered vehicles in the near future, the adoption of electric buses and trucks is ramping up quickly. Sono makes solar power collection kits for those larger vehicles, and even if the systems add a small bit of power to the batteries each day, in aggregate, the total “free energy” collected would be a massive amount that makes real differences in how much power a city has to buy for its EV fleets of buses and trucks. Just a few percentage points of difference translates into millions of dollars over time – and the systems can also be used on gas-powered buses to run AC and other lower-draw systems, saving diesel fuel. Again, in aggregate, the total savings over time would be significant.
And time is on Sion’s side. Solar systems powering an ever-increasing part of our economies will be a big part of the world-wide energy matrix going forward, and over time, solar technology will be continually refined, improved, made more efficient, cost less and likely be mandated into use as cities and EV buyers realize the savings as terawatts of energy in the form of sunlight is increasingly collected by solar tech. It’s literally free energy pouring down out of the sky each day, rain or shine (more during shine, of course), and both the average consumer and municipal leaders are beginning (at long last) to realize the long-term promise of solar power.
Eventually, every car, truck, bus and who knows, perhaps even trains and airplanes, will collect the sun’s energy through solar systems so cleanly integrated into the vehicles that we won’t really even be able to see them. And we can point back to that classic boxy Sion covered unapologetically in solar cells as a point in which that huge change began to take place. The Sion is open for preorders now.