While people typically perceive Tesla as an electric-car company, the actual goal of Elon Musk's company has been to accelerate the large-scale adoption of sustainable energy.

This past week, Musk made good on the company's vision by unveiling the Tesla Solar Roof, made of textured glass tiles with integrated solar cells that are nearly indistinguishable from conventional tiling. In concert, he also announced an upgraded model of the company's energy-storing Powerwall.

The Powerwall 2 is a battery for homes and small businesses that stores the sun's energy and delivers clean, reliable electricity, even when the sun isn't shining.

According to a report by Wired:

A couple hundred invited guests, mostly Tesla owners, ooh-ed and ahh-ed as Musk revealed that a row of suburban American houses on Wisteria Lane—the old set of Desperate Housewives—were all, in fact, topped with solar roofs. Each house's old roofing material had been stripped away, and replaced with one of four new styles of solar tile. From the street, it was virtually impossible to tell; the roofs retained a variety of traditional looks, from textured slate shingle to terra cotta tile.

Musk said the secret to the tiles' appearance is a special coating that becomes more or less see-through depending on your viewing angle. He described it as a series of micro louvers that work like a privacy screen on a laptop, and said the company is working with 3M on the tech. The effect is dramatic in person. From shallow angles, the tiles appear nontransparent. But as your viewing angle approaches 90 degrees, the underlying solar cell becomes more and more visible. The result is a tile that permits the passage of sunlight from overhead, but still looks opaque to anyone at ground level.