A prototype panoramic roof with integrated perovskite-based photovoltaic cells has been created.
Hongqi has unveiled what it calls the automotive industry's first prototype panoramic roof with integrated perovskite photovoltaic cells. The technology has been installed on the Hongqi EHS7 electric SUV and can generate up to 300 watts under bright sunlight, providing power for the vehicle's auxiliary systems.
The EHS7 being used to test the technology is known as the Tiangong 08 in China. Instead of mounting conventional solar panels on top of the vehicle, Hongqi has integrated the photovoltaic cells directly into the panoramic glass roof.
The electricity generated from sunlight can be used to power the air-conditioning system, an in-car refrigerator and the vehicle's security system. This allows those auxiliary systems to operate without drawing power from the main traction battery.
According to Hongqi's engineering estimates, the solar roof could generate approximately 400 kWh of electricity per year. The prototype's peak output reaches 300 watts under strong sunlight.
The photovoltaic cells use perovskite, a material that Hongqi says is thinner, lighter and more flexible than conventional crystalline silicon. Those characteristics make it possible to integrate the technology into curved automotive glass surfaces.
One of the biggest engineering challenges was protecting the perovskite cells from moisture, oxygen and ultraviolet radiation. Hongqi's engineers also had to adapt the system to the panoramic roof's complex double-curved shape.
The automaker plans to expand the area covered by the photovoltaic material in the future. Solar cells could eventually be installed not only in the roof but also on the hood and other exterior body panels.
With a larger solar collection area, Hongqi estimates that the system could eventually generate up to 10 kWh of electricity per day. The company claims that amount of energy could be equivalent to roughly 50 miles of additional driving range, depending on the vehicle's efficiency and operating conditions.
The solar roof is part of Hongqi's broader development program for electric-vehicle technology. Other projects include the integration of BYD Blade 2.0 batteries and the development of solid-state battery technology.
Hongqi has not yet announced when the solar technology could enter series production.