Engineers from Audi have designed a type of car laminate that can absorb solar energy, and offers the flexibility conventional glass solar panels cannot.
The German carmaker’s patent application includes three designs for the solar laminate. The most basic embodiment consists of multiple thin, flexible layers as shown below.
Fig. 1 A schematic diagram of the laminate.
Audi’s solar laminate comprises cover film (2) made of plastic material transparent to incident light radiation, solar cell film (3) made of photoactive materials, and a support layer (4) made of glass fiber- or carbon fiber-reinforced composite material. An adhesive layer (5) is optional and does not necessarily have to be applied at the factory.
The two other embodiments add intermediate film layers above and beneath the solar cell layer which are meant to add protection against the cover film and support layer, respectively. Audi says these intermediate films may be constructed using the same plastics material as the cover film.
The patent application cites the reliance of current solar-powered cars on glass components, typically only located on their roofs. These components, comprising solar cells sandwiched between glass layers, are rigid and limiting in terms of their handling and possible uses.
Fig. 2 Vehicle components where flexible solar panels may be applied.
The glass and solar cell approach Audi mentioned was employed in a version of the 2019 Hyundai Sonata. The South Korean automaker touted the hybrid’s solar roof charging system and its ability to provide additional electrical power. Unfortunately, the feature was reportedly impractical: it did not provide enough power to justify leaving the Sonata parked under the sun. Audi’s patent application does not mention the specific solar power gain of the flexible panels, only that they convert light to electricity with a “sufficiently high degree of efficiency.”
The featured patent application, “Photovoltaically Active Laminate”, was filed with the USPTO on June 5, 2019 and published thereafter on June 24, 2021. The listed applicant is Audi AG. The listed inventors are Wojciech Brymerski and Annegret Matthai.