A technology that captures sunlight as heat energy within molecules and converts it to electricity could be a portable battery substitute.

A rechargeable device that stores solar thermal energy in a liquid or solid form and converts it to electricity when needed could one day power your smartphone and eliminate the need for batteries.

Kasper Moth-Poulsen and his colleagues at Chalmers University of Technology in Gothenburg, Sweden, have developed a compound made composed of carbon, hydrogen, and nitrogen molecules that can store solar energy for months or even years.

When light from the sun strikes the molecules, they change shape.