ACS Nano published an article on the revolutionary technology that reveals the 24% overall energy efficiency. Surprisingly, however, the team is hoping to use the solar steam invention not for electricity generation, but for sanitation and water purification.
The light-capturing nanoparticles convert sunlight into heat and create the high efficiency of the solar steam. The particles heat up very quickly when exposed to sunlight and submerged in water, which vaporizes the liquid.
Naomi Halas, LANP Director and lead scientist on the project explains how the heating coming from the particles is very intense, due to their extremely small size. This generates steam locally on the surface of the particles.
Oara Neumann, a graduate student at Rice, filmed the process of submerginf light-activated nanoparticles into ice water. With the help of a lens to concentrate the sunlight, she demonstrated how steam is created.
Steam is responsible for nearly 90% of the world’s electricity production, it is used widely as a sterilizer for medical waste and surgical instruments, and it is a key element in food preparation and water purification.
In this respect, the main benefits of this technology will be noticed firstly by citizens of developing countries. Students at Rice have already developed autoclave powered by solar-steam, which can be used for sterilizing medical instruments in areas where electricity is lacking.
In addition, Halas was given a grant by the Bill and Melinda Gates Foundation to create an ultra-small-scale system for treating human waste.
According to Neumann, the key is that solar steam does not require mirrors or solar panels to achive the high efficiency. This gives the opportunity to expand the scope of the technology and be used in powering heating systems or air-conditioning systems.
The task Halas and Neumann have set was to design a particle that can interact with sunlight energy at any wavelength spectrum, hence why the nanoparticles that they developed are activated by both visible sunlight and shorter wavelengths.