Robert F. ServiceRefrigerators, boilers, and even lightbulbs continually dump heat into their surroundings. This “waste heat” could—in theory—be turned into electricity, as it is sometimes done with power plants, automobile engines, and other high-heat sources.
The problem: These “low-grade” sources give off too little heat for current technology to do the conversion well.Now, researchers have created a device that uses liquids to efficiently convert low-grade heat to electricity.