The C-Max Solar Energi Concept Car will be unveiled at CES in Las Vegas next week. / Ford

New concept uses 'magnifying glass' canopies to focus sunlight onto roof-mounted solar panels, with a final range range of 550 miles

Ford is set to reveal a new hybrid car that will be partly powered by solar panels on the roof. Although there are no plans to sell the C-Max Solar Energi Concept to the public, the technology developed by the car-manufacturer could eventually find its way into commercial vehicles.

Coupling solar-power with electric cars is not a new idea, but many previous iterations have been hamstrung by the a recurrent challenge: the fact that solar panels simply aren't efficient enough to power a car, even if you leave a vehicle out in the sun all day long.

Ford has introduced a new to combat this in the form of a "solar concentrator": a steel frame that essentially acts as a giant magnifying class for the vehicle, although it's made from plastic rather than glass.

Users park their car under the five metre tall canopy, using this to focus the sun’s rays onto the roof-mounted solar panels with a surface area five times larger than that which would be provided by the vehicle alone.

In order to further increase the efficiency of this process the vehicle will also position itself autonomously underneath the concentrator, moving back and forth to track the sun across the sky.

The Energi Concept will get the same performance as the commercially available C-Max Energi that it's based on (another hybrid - but one that requires an electrical plug to charge it up), with a range of 620 miles and ability to travel for up to 21 miles from solar power alone.

"By using renewable power, the C-MAX Solar Energi Concept is estimated to reduce the annual greenhouse gas emissions (GHG) from a typical owner by four metric tons," says Ford.

However, as MIT Tech Review have noted, there are still quite a few problems with the technology, including some fairly basic ones, like keeping people from walking underneath the canopy and getting burned by the focused sunlight.