Greenhouse effect’ used to generate electricity

A device that gets scorching hot as it captures and traps much of the sun’s energy using a greenhouse-like approach could usher in an era of inexpensive electricity from the sun.

The breakthrough comes from a sunlight-absorbing material made of photonic crystals that are arranged to prevent the escape of most of the energy it captures from direct sunlight.

The concept is similar to the way carbon dioxide molecules in the atmosphere trap the sun’s energy, which keep the planet warmer than it would be if all the energy escaped to space.