Hyundai has joined the ranks of manufacturers that are utilising solar charging technology to make their hybrid cars more energy efficient. The Korean manufacturer has launched solar charging on the Sonata Hybrid, and whilst the model doesn't make it to these shores, both Hyundai and Kia have already promised that the technology will be rolled out across markets on future hybrid and battery electric vehicles.

Solar has gained a fresh impetus recently, with Toyota testing high-efficiency solar panels on its Prius and Dutch start-up, Lightyear, launching its solar-assisted hybrid.

On the Sonata, the roof-mounted silicon solar panels provide energy to power both on-board electrical systems that would usually take power from the hybrid powertrain, and the hybrid battery pack itself. This additional source of power over and above that generated by the engine and energy recuperation, decreases CO₂ emissions and increases fuel efficiency.

According to Hyundai, with six hours' charging time per day in ideal conditions, solar energy can charge the on-board 1.76kWh battery by between 30 per cent and 60 per cent per day. And this charging continues while driving the Sonata, ensuring that no power is wasted. The figures suggest that owners of the Sonata Hybrid can gain over 800 miles of purely solar powered driving per year.

The system itself is relatively straightforward and has been designed to blend into the overall look of the Sonata. It comprises the solar cells themselves (though we don't know their specific efficiency or output) and a controller that converts the charge into standard voltage which is fed into the car's electrical system.

“Solar roof technology is a good example of how Hyundai Motor is moving towards becoming a clean mobility provider. The technology allows our customers to actively tackle emissions issue,” says Heui Won Yang, Senior Vice President and head of Body Tech Unit of Hyundai Motor Group. “We are striving to further expand the application of the technology beyond eco-friendly vehicle line up to vehicles with internal combustion engine.”

The Sonata Hybrid with solar charging is available in Korea and will soon be available in the USA, whilst European models will get the technology in the not-too-distant future.