Solar-powered Ford C-Max Energi hints at future without gas, or even plugs

Engineers, including university students, have been working for decades on sun-powered cars. But the reality is, today’s solar panels just don’t generate enough energy to meet modern driving demands on even sunny days. However, the C-Max Solar Energi concept being shown next week at the International CES show in Las Vegas looks to go the distance—literally. Based on a production car, the key to the C-Max Solar Energi is that it has a gasoline engine, so you’re not stranded when the sun doesn’t shine. (Read our Ford C-Max road test.)

The C-Max Solar Energi concept is basically a conventional C-Max Energi plug-in hybrid with an advanced solar array riding on top. Because the roof can’t hold enough solar panels to collect a full battery charge in a day, Ford has worked with utility solar provider SunPower to develop a solar concentrator that magnifies the solar rays hitting the cells and tracks the sun as it moves across the sky. Using the solar collector can fully charge the C-Max Energi’s standard 7.6-kWh battery in a day. That gives the car a claimed range of 21 miles before the gas engine needs to start to keep powering the car. Ford says this is enough for 75 percent of the trips C-Max Energi drivers take. (Read: "Many Americans are just a plug away from owning an electric car.")

Ford calls the device an "off-vehicle" solar collector, so we’re not sure where owners would keep it when it’s off the vehicle. The C-Max Solar Energi concept also has a conventional charge port to plug into the electrical grid—perhaps for those cloudy days—reinforcing its similarities to a plug-in hybrid.

The C-Max Solar Energi could provide a solution for those who want to drive an electric car, but have no place to plug in where they park.

In a recent electric-car survey, we found 48 percent of respondents said they park on the street or have no place to plug in where they park. Just park the car outside, and it will charge the batteries. But you’re still only likely to get a full charge every day if you live in the southwest and the skies are not cloudy all day. We think a better solution is to get a plug-in car and put solar panels on your house. That way, you can have a much larger solar array and offset the cost of charging the car. And, you can still park in the garage.

—Eric Evarts

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