The dream of a solar-self-charging electric vehicle lives on. A Ford patent application was published this week for a roof-mounted device that, with a flip of a switch, cocoons the entire parked vehicle in a shield of solar panels. The patent application was filed on November 8, 2019, and published on May 14, 2020
It’s been more than six years since Ford unveiled its C-Max Solar Energi Concept. In 2014, at CES, Ford showed the rooftop solar system that tracks the sun’s movement and uses a Fresnel lens to concentrate its energy to charge the C-Max plug-in hybrid. The company claimed the system could produce 8 kilowatts of power.
Ford is not alone in its pursuit of putting solar panels on EVs. Toyota, Hyundai, Nissan, and Tesla have all made forays into using rooftops to solar-charge an EV or hybrid. Ford’s new patent application describes the technical challenge:
The problem is that the surface of a motor vehicle for fitting the solar cells is relatively restricted and therefore not sufficiently large.
Therefore, what Ford outlines in its new patent application is a strange, rooftop-mounted shape-shifter: an “auto-covering fabric” with “flexible thin-lay solar cells” controlled by a “central shaft arranged on a rear bumper or in a luggage compartment.”
The Ford patent application also describes the cover as a “flexible shield” that gets unfolded via “an inflation pump,” which is self-powered from the system’s stored solar power. The shield’s shape, when fully deployed, is maintained through “memory polymer.”
The driver activates the system with a “slider” so that the solar-power cocoon “can be switched between an extended and a stowed state.” I want to see this in action.
Last month, we shared news and a video about a somewhat similar device that unfurls a solar coverover the vehicle rather than dropping a shield over the car. It uses a tarp with ultra-thin organic photovoltaic film.
When that solar tarp is deployed, it still only has as much surface as the car’s exterior. From what we can tell, Ford’s approach that deploys from a rooftop box would broaden the surface area to a much larger bubble around the vehicle
Lightyear, the Dutch solar-car company, designed the body of its Lightyear One vehicle to be as aerodynamic as possible while maximizing the space for solar cells. Its design features enough sky-facing surface area to place about 1,000 individual photovoltaic cells on its body. The Lightyear One, if left in the sun, averages about 20 miles of added electric range in a day. The first hand-built production model, due in 2021, will cost $165,000.
Lex Hoefsloot, chief executive at Lightyear, told me:
People say they want a car to charge itself. Therefore, I think it’s the endgame of where we’re heading with electric cars.
The next best thing, I suppose, would be an EV that, while parked, would slowly but surely accumulate more range.
This week, Lightyear and Royal DSM, a company that makes everything from medical devices to solar coatings, announced a partnership. The goal is to commercialize Lightyear’s technology by offering it to other automakers.
That pivot by Lightyear, and Ford’s new patent, reveals that the dream of solar power to self-charge an EV is not going away.
Obviously, the filing of a patent does not mean an idea will be commercialized. The odds aren’t good for Ford’s inflatable solar-powered EV-charging car shield.
Like many EV drivers, I have rooftop solar at my house. The majority of the system is mounted on the carport where I park my EV every night. That provides more space and efficiency than any system that could be installed on the car itself.
However, solar efficiency will continue to improve, and it would be nice to benefit from solar charging when I’m away from home. Only time will tell if these systems will improve enough so that we’re all driving around in EVs that charge themselves by harnessing the power of the sun.