Super-Efficient Solar-Energy Technology: Major Advance In Using Sunlight To Produce Steam Without Boiling Water

Scientists are describing a revolutionary new way to use sunlight to produce steam and other vapors without heating an entire container of fluid to the boiling point. The advance, reported in the American Chemical Society (ACS) journal ACS Nano, has potential applications, especially in the poverty-stricken areas of the developing world, that include inexpensive, compact devices for purification of drinking water, sterilization of medical instruments and sanitizing sewage.

“This research opens up a revolutionary new application of nanoparticles in solar energy,” said Paul Weiss, Ph.D., editor-in-chief of ACS Nano, one of more than 40 peer-reviewed scientific journals published by ACS, the world’s largest scientific society. “The authors show that sunlight can be used to create steam with virtually no wasteful heating of the surrounding liquid. The potential societal benefits are staggering. They include more energy-efficient distillation of alcohol, a new and highly practical strategy for desalination and water purification and compact solar-driven sources of steam for sterilization and sanitation in resource-poor locations,” said Weiss.

Naomi Halas, D.Sc., Peter Nordlander, Ph.D., and colleagues note in the report that metallic nanoparticles (so small that 1,000 would fit across the width of a human hair) absorb large amounts of light, resulting in a dramatic rise in their temperature. They are with Rice University. That ability to generate heat has fostered interest among scientists in using nanoparticles in a range of applications. These include photothermal treatment of certain forms of cancer, laser-induced drug release and nanoparticle-enhanced bioimaging.

New solar steam technology developed at Rice University uses nanoparticles so effective at turning sunlight into heat that it can produce steam from icy-cold water.