A startup in Germany has developed a new kind of solar panel made of small, organic molecules deposited on polyester films. The technology is similar to what's used for OLED displays for phones and flat-screen TVs. The panels are flexible, and far lighter than conventional solar panels, yet in some locations—particularly where it's hot or cloudy—they can generate just as much electricity as a conventional solar panel.

Heliatek, based in Dresden, is funded by Bosch, BASF, and others, and has raised 28 million euros so far. The company, which recently started making its panels on a small, proof-of-concept production line, hopes to raise an additional 60 million euros, part of which will be used to build a 75-megawatt factory. This is fairly small for a solar panel factory—at such a small scale, Heliatek's panels will cost more per watt than conventional solar panels, says CEO Thibaud de Séguillon. But in four to five years, by which time Heliatek should reach large-scale production, the cost could drop to around 40 to 50 cents per watt, which would make them competitive with conventional solar panels, he says.