Hyundai, with the third-generation Sonata Hybrid (in limited trim), has the first vehicle that has a solar panel roof that helps generate power for the hybrid battery and to power on-board systems.
Impact and efficiency of the solar panel roof
The solar panels used on the new Sonata are 3-6% more efficient than your average roof photovoltaic solar panel. Over the course of an average day, the Sonata can generate up to 2 miles of additional range, purely from the solar roof.
Even with dirty roofs, the Sonata can still generate 90-95% of the expected energy boost. That being said, it won’t hurt to keep it clean to maximize your free energy.