A team of researchers at Rice University has developed a new technology that uses light-absorbing nanoparticles to convert solar energy directly into steam. Even though it is already significantly more efficient than solar panels at producing electricity, the technology will likely find its first applications in low-cost sanitation, water purification and human waste treatment for the developing world.

Approximately 90 percent of the world’s electricity is produced from steam turbines. Most industrial steam is produced in large, expensive boilers, but because of its very small footprint and high efficiency, this new development promises to make steam economically viable on a much smaller scale. Sterilizing medical waste and surgical instruments, preparing food and purifying water could soon become within reach of a large chunk of the developing world, that doesn’t have access to the electrical grid.

The Rice technology relies on light-absorbing nanoparticles. When they are submerged and then illuminated, these particles can very quickly reach temperatures well above the boiling point of water. At this stage, they quickly dissipate heat through their very small surface area, which almost instantly results in 150°C (300°F) steam generated right at the surface of the particle. The system is so effective that it can even turn […]