But as oil prices plunged in the Clinton era, the U.S. abandoned its grand solar experiment, and molten salt technology got shoved into cold storage.

FORBES: Secret Ingredient To Making Solar Energy Work: Salt

He dreams of building gigawatt-size plants, of shipping solar thermal power to the cloudy Northeast and of using molten salt to store energy so thermal plants can power homes at night. (Nevada Solar One is only for daytime peak loads.) He envisions mirrors in space that can soak up sunlight 24 hours a day.

FORBES: Light And Heat

Now salt is back on the table as states such as California green-light big solar thermal power projects to meet ambitious renewable energy mandates.

FORBES: Secret Ingredient To Making Solar Energy Work: Salt