Ford's new concept for solar-powered hybrid car can run for 21 electric-only miles on a day's worth of sunlight. That possibility comes courtesy of sun-tracking software that works in combination with a concentrator lens to focus the sunlight falling on the car's rooftop solar panels.
The C-MAX Solar Energi Concept car—a modified C-MAX plug-in hybrid—won't achieve the dream of driving forever on sunshine just yet. But Ford's clever use of a concentrating lens does provide an inkling of new hope for solar power to someday become viable in hybrid or all-electric vehicles. Until now, solar power's energy density problem has limited its use in commercial vehicles to not much beyond a symbolic rooftop solar panel that runs a cooling fan for Toyota's Prius hybrid car.
Ford envisions its concept car parking beneath a tall carport with a roof made of a Fresnel lens—a lens originally developed for lighthouses that acts similar to a magnifying glass. The car company enlisted the help of Georgia Institute of Technology researchers to come up with the carport's sunlight-concentrating design.
The car's software would track the sun's path across the sky on any given day of the year and direct the car to move beneath the carport so that it continually receives the full impact of concentrated sunlight, according to Technology Review. That novel concept eliminates the need for an expensive tracking system that would change the angle of the carport's lens to keep sunlight focused on an immobile car's rooftop solar panels. (The concept car also has a traditional charging port so that it can plug into the power grid if needed.)
Such concentrated sunlight could reach 8 times the amount of sunshine that would typically fall on the C-MAX Solar Energi's rooftop. A day's worth of charging in the sun—about 8 kilowatts over four hours—would go into the lithium-ion battery that provides the 21 electric-only miles in the car's total range of 620 miles. Ford estimates suggest the C-MAX Solar Energi Concept would have the same total range on a full charge as compared to the conventional C-MAX Energi.
The U.S. automaker has big plans for its concept car following a debut at the 2014 Consumer Electronics Show, 7-10 January in Las Vegas. Ford will work with Georgia Tech to begin testing the vehicle in "real-world scenarios" and see whether its concept can prove practical in everyday life—a challenge that may yet pose some headaches. For instance, Toyota's engineers previously found that connecting rooftop solar panels to the battery of a Prius created an antenna-like effect that interfered with the car's radio.
Most car companies have settled for slightly less ambitious goals involving the use of solar power. Tesla Motors has opted for solar-powered charging stations that keep the solar panels off the roofs of its sleek vehicles.
Still, the benefits of a solar hybrid vehicle could prove worthwhile in the long run. Ford says its internal data already suggests sunlight could power up to 75 percent of the trips made by an average driver in a solar hybrid vehicle. And the C-MAX Solar Energi could also slash greenhouse gas emissions from typical U.S. car owners by as much as four metric tons per year—about what a U.S. household produces in four months.