It also likes companies that are working on making smaller batteries, like Qynergy, a New Mexico-based company working on radioisotope batteries, and Infinite Power Solutions, a Colorado developer of thin-film batteries that can power RFID (Radio Frequency Identification) tracking chips.

FORBES: Business In The Beltway

This design, combined with flexible, thin-film batteries, could lead to a flat device that is far less obtrusive than a lumpy generator.

ECONOMIST: Case history

It is an inflatable pouch that has a thin-film solar panel with two-coin cell rechargeable batteries.

FORBES: Social Enterprise Spotlight: Portable Solar Lighting