“Ford to debut solar car” said the CNN headline. Since all previous “solar cars” have been specialized racers, or used photovoltaic panels to, maybe, power the cigarette lighter or run a fan, I was expecting the reality to be far less than advertised. I have a long history of skepticism about sun-powered vehicles.
Yet the Ford C-Max Solar Energi, to be shown at the giant Consumer Electronics Show (CES) in Las Vegas next week, really is a solar car. Like the Toyota Prius and the late, lamented Fisker Karma, the Solar Energi has a rooftop panel (below), in this case SunPower cells rated at 300 to 350 watts. That’s the system on the car, and it’s not that unusual, but what’s off the car is much more interesting.
Ford teamed with Georgia Institute of Technology to build an solar concentrator with a Fresnel lens (the type used in lighthouses) that beams sunlight at the cells on the car while “boosting the impact of the sunlight by a factor of eight.” The Fresnel lens acts like a magnifying glass to concentrate power, and the system tracks the sun as it moves east to west. In a day, it can generate enough electricity to equal a four-hour, eight-kilowatt battery charge.
Up to 75 percent of all trips an average hybrid driver takes in the car could be solar powered, Ford data suggests. The annual reduction in greenhouse gas by using this car could equal four metric tons (a house’s output for four months). If every car and light truck in the U.S. had this technology, the reduction would be a billion metric tons. Now we're going beyond the solar racers, and I’m starting to pay attention!
Ford seems to have come up with a very effective solar charging system, but my guess is that Fresnel lenses and sun trackers don’t come cheap (though the company describes it as a "low-cost option."). The Solar Energi is a display vehicle at CES, not something with production intent. Mike Tinskey, Ford global director of vehicle electrification, says he's "optimistic" on the cost of the system. "This is not without challenges," he said. "But we're optimistic about this opportunity primarily because it's clean and green, its not dependent on electricity availability and it's a viable solution in the developing world where a grid infrastructure is often lacking. We like to call it the first plug-in hybrid that doesn’t need to plug-in."
But if you really do want a solar charger you can buy now, Envision Solar is marketing the EV ARC (Autonomous Renewable Charger), which is a portable solar electric car charger with a 2.3-kilowatt solar array, battery storage, and its own built-in parking space. It can generate 16 watt-hours daily and store 22, and if you don’t like the performance where it is, you can move it around in a truck. The unit generates enough power to charge one car daily.
The big benefit is that you don’t need permits, and you don’t need to dig a trench to connect it to the grid. The downside is the $40,000 price tag. Desmond Wheatley, Envision’s CEO, told me he could halve the price if he gets big orders for his solar charging pad. “We believe the cost points will end up being incredibly competitive,” he said.
But if $40k is too much, you could always consider 36-watt PowerDrive Solar—for your golf cart. That’s just $997. “Run all day without plugging in!”
Here's a deep dive into the solar concentrator technology from Ford: