Ford unveils C-MAX Solar Energi concept; “plug-in” hybrid not dependent on electric grid can fully recharge from sun

Ford’s C-MAX Solar Energi concept combines a rooftop solar panel with an off-board solar concentrator—essentially an inexpensive Fresnel lens canopy. The vehicle moves beneath the canopy during the day to maintain maximum concentrated solar irradiance. Click to enlarge.

Ford Motor Company announced the C-MAX Solar Energi Concept, a sun-powered hybrid vehicle that can deliver the efficiency of a plug-in hybrid without depending on the electric grid for recharging. Instead of recharging its battery from an electrical outlet, Ford C-MAX Solar Energi Concept uses a special Fresnel lens-based solar concentrator as a stationary canopy working with solar panels on the vehicle roof to recharge directly from the sun.

The concept vehicle uses a day’s worth of sunlight to deliver the same performance as the conventional C-MAX Energi plug-in hybrid, which draws its power from the electric grid. Ford C-MAX Energi gets a combined EPA-estimated 108 MPGe city and 92 MPGe highway, for a combined 100 MPGe. C-MAX Solar Energi Concept, which will be shown at the 2014 International CES in Las Vegas, is a collaborative project of Ford, SunPower Corp. and Georgia Tech.

Ford C-MAX Solar Energi Concept. Click to enlarge.

SunPower, which has been Ford’s solar technology partner since 2011, is providing high-efficiency solar cells for the roof of Ford C-MAX Solar Energi Concept—about 1.5 m² worth, according to Mike Tinskey, Ford’s Director, Vehicle Electrification and Infrastructure. Because the PV cells alone would generate only about 300W—insufficient to charge the vehicle’s battery—Ford turned to Georgia Institute of Technology for a way to amplify the sunlight in order to make a solar-powered hybrid feasible for daily use.

Researchers developed an off-vehicle solar concentrator that uses a special Fresnel lens to direct sunlight to the solar cells while boosting the impact of the sunlight by a factor of eight. The Fresnel lens is a compact lens originally developed for use in lighthouses. The patent-pending canopy-vehicle system tracks the sun as it moves from east to west, drawing enough power from the sun through the concentrator each day to equal a four-hour battery charge (8 kW).

With a full charge, Ford C-MAX Solar Energi Concept is estimated to have the same total range as a conventional C-MAX Energi of up to 620 miles, including up to 21 electric-only miles. Additionally, the vehicle still has a charge port, and can be charged by connecting to a charging station via cord and plug so that drivers retain the option to power up via the grid, if desired.

After C-MAX Solar Energi Concept is shown at CES, Ford and Georgia Tech will begin testing the vehicle in numerous real-world scenarios. The outcome of those tests will help to determine if the concept is feasible as a production car.

By tapping renewable solar energy with a rooftop solar panel system, C-MAX Solar Energi Concept is not dependent on the traditional electric grid for its battery power. Internal Ford data suggest the sun could power up to 75% of all trips made by an average driver in a solar hybrid vehicle. This could be especially important in places where the electric grid is underdeveloped, unreliable or expensive to use.

The vehicle also reinforces MyEnergi Lifestyle, a concept revealed by Ford and several partners at 2013 CES. MyEnergi Lifestyle uses math, science and computer modeling to help homeowners understand how they can take advantage of energy-efficient home appliances, solar power systems and plug-in hybrid vehicles to significantly reduce monthly expenses while also reducing their overall carbon footprint.