One of the most fascinating aspects of Tesla’s solar roof, which started reaching homes earlier this year, is that it looks like an ordinary roof. The design hides advanced energy-harvesting cells wired to a home battery, and a new patent application published last week by the United States Patent and Trademark Office sheds light on how the company pulled off the technical feat.
Tesla’s description of the invention, as listed in the patent’s abstract, explains the tile “includes a backsheet layer, a bottom encapsulant layer adjacent the backsheet layer, a plurality of photovoltaic cells adjacent the bottom encapsulant layer, a top encapsulant layer adjacent the plurality of photovoltaic cells having a plurality of louvers constructed therein to block side view of the plurality of photovoltaic cells, and a top layer adjacent the top encapsulant layer.” In other words, the louvers inside the tiles act like blinds in a window. The light hitting the roof from the sky passes through, but from the street level the louvers block the sight of the cells and make the tiles appear smooth.
The breakthrough is a key part of Tesla’s strategy to bring about an energy revolution. When CEO Elon Musk unveiled the tiles in October 2016, he said it “needs to be beautiful.” The tile was unveiled as part of a “house of the future” vision, with a Tesla Model 3 electric car in the garage and a Tesla Powerpack battery storing leftover energy.