Hairy solar panel!

California Institute of Technology has come up with cheap, flexible and efficient solar panels. Instead of making the wires with exotic materials like "indium gallium phosphide", they made them mostly out of plastic with a bit of silicon (2% silicon, 98% is polymer).

These solar cells have, for the first time, surpassed the conventional light-trapping limit for absorbing materials, said the team. The light-trapping limit of a material refers to how much sunlight it is able to absorb. The silicon-wire arrays absorb up to 96 percent of incident sunlight at a single wavelength and 85 percent of total collectible sunlight. A record so far.

Each of the silicon wires (30 and 100 microns in length and only 1 micron in diameter) is a good solar cell on its own, and the light that isn't absorbed is scattered and then hits other wires.

The flexibility of the panels is also important because it means that they can be manufactured using roll-to-roll processes, reducing production costs compared to non-flexible panels.

So far only a few square centimeters of cells have been made, but the Caltech team is already working on making new demonstration panels. The race is certainly hotting up.