Ford estimates that motorists could save approximately $500 (about £300) per year in energy bills if the company’s conceptual solar-powered C-Max was ever made viable for production.

The Ford C-Max Solar Energi Concept, unveiled at the International CES technology expo in Las Vegas this week, is based on the plug-in hybrid version of the Blue Oval’s medium-sized people carrier currently on sale in the US.

The roof features a 1.5-square-metre array of 275W photovoltaic cells supplied by Ford’s solar technology partner, SunPower.

To recharge, the car sits under a canopy of approximately 15-20 square metres in size – slightly larger than the average parking space. It acts as a Fresnel lens, concentrating more of the sun’s rays onto the Ford’s solar panels.

Ford says the car uses existing autonomous driving technologies, such as the auto-park function that is already a feature of the C-Max, to move a few metres during the day to track the sun’s movement through the sky.

Using this method, Ford says the C-Max’s lithium ion batteries can be recharged in about eight hours, based on the average amount of sunlight received by US cities.