Ford is to unveil a solar-powered hybrid concept car capable of 100 miles per gallon that offers the same performance as a plug-in hybrid – but without the need for a plug.

The C-Max Solar Energi Concept car, which will be revealed at the International CES gadget show in Las Vegas next week, uses a petrol engine combined with a gizmo that acts like a magnifying glass to concentrate the sun's rays on the vehicle's roof-mounted solar panels.

Ford says the vehicle's estimated combined mileage is 100mpg.

By using solar power instead of an electric plug, the manufacturer says a typical owner will reduce annual greenhouse gas emissions by four tonnes.

The company sold about 85,000 hybrid or electric vehicles last year, including 6,300 units of its C-Max Energi plug-in hybrid.