Hyundai has developed a roof-mounted solar charging system that connects directly to the powertrain of an electric vehicle (writes Nick Flaherty).
The latest Sonata hybrid electric car will have solar cells in the roof that for the fi rst time can charge the battery pack to extend range
Previous roof implementations have used the energy generated to power ancillary equipment such as entertainment systems or air conditioning fans rather than the main battery pack. By contrast, Hyundai’s system uses a solar panel and a controller that converts the energy to the 270 V needed for the battery pack.
Hyundai produces passivated emitter rear locally diffused monocrystalline silicon solar cells that have a conversion efﬁ ciency of 17.9%. These use local back surface ﬁ eld technology on the back of the cells for connecting them together to avoid blocking the sunlight.
Operating during the daylight hours means the solar roof system can charge 30-60% of the battery each day.
The solar roof will be used on the upcoming Sonata Hybrid, along with Active Shift Control technology on a sixspeed transmission (see story below).