Power Plastic, a new lightweight, flexible, and cheap material that converts indoor and outdoor light into electricity. Think of it as a solar panel that rolls up like camera film. "Soon you may not even need batteries," Hess says, holding a prototype of a portable device that will recharge your cellphone in an hour. "We can put this stuff anywhere."

Konarka's film rolls off a converted printing press that used to belong to Polaroid. It prints a secret plastic ink onto rolls of thin film. As it absorbs light, the polymer ink emits electrons, producing electricity.

In a few years, Hess says, Konarka will have perfected a translucent version of its product that could be built into the windows of skyscrapers, generating enough power to run whole buildings.