Panasonic Supplies Solar Roof Panel for Prius

Panasonic Corp. says it is supplying the photovoltaic solar roof array for Toyota Motor Corp.’s Prius PHV plug-in hybrid sedan in Japan.

The solar panel is capable of producing 180 watts of electricity—three times more than other automotive photovoltaic systems—to power unspecified vehicle accessory systems and partially charge the hybrid car’s lithium-ion battery pack, which Panasonic also provides. Photovoltaic modules offered in previous Prius models were limited to applications such as ventilation for the car’s air conditioning system, according to the supplier.

Toyota previously has said the solar roof can boost fuel efficiency by as much as 10%. Energy generated from the panel’s photovoltaic cells can be used to recharge the Prius’ 8.8-kWh battery pack when the car is parked or in motion.

The solar cell structure combines a crystalline silicon substrate and an amorphous silicon film. Panasonic also developed a unique lamination technology that thermally bonds the upper and lower surfaces to allow the panel to conform to the contours in the Prius’ curved roof.

Toyota said earlier that the solar panel initially wouldn’t be available in the U.S., where the car is known as the Prius Prime, or Australia, because the system is installed on reinforced glass sheeting that doesn’t meet rollover crash regulations. It isn’t clear if the new Panasonic unit meets U.S. standards.