Future car models from German maker BMW could be equipped with roof-mounted solar panels aimed at saving fuel and cutting pollutants.
The energy from the sun would be used to top up the car's battery or else pre-warm liquids in the engine to make cold starts less wearing on mechanical parts and also more fuel-efficient.
The solar panels were showcased on a BMW X5 diesel hybrid SUV (Sports Utility Vehicle) at the Geneva Show earlier this year but there was no word from Munich on when they might be ready for production cars.
According to BMW, a square metre of solar panelling is sufficient to generate enough electrical power to run or charge up onboard systems such as navigation devices and cellphones.
It could also be used to pre-warm air-conditioning systems.