Providing clean water in regions where this resource is scarce is a major challenge, and for which there are many ingenious solutions. A research team from the US Army and the University of Rochester has developed a new system, a super efficient aluminum panel that uses solar energy to purify water.
Solar power has proven to be a smart and popular choice for powering low cost water purifiers.
Sunlight has long been known to destroy waterborne pathogens. Over the years, we’ve seen a number of technologies take advantage of this process to produce clean water through low-cost portable platforms, but the researchers behind the latter say it offers a revolutionary level of efficiency.
The technology begins with a normal aluminum panel, which is treated with ultra-short laser pulses to produce a black surface with open slits. This makes the material very absorbent, allowing it to extract a thin film of water from a deposit on the metal surface, even against the forces of gravity.
When this happens, the black material collects energy from the sun and is able to hold it to heat the water. The structures etched on the surface of the metal alter the molecular bonds of water, increase the efficiency of the evaporation process which frees it of its pollutants.
Together, these three elements allow the technology to perform better than an ideal device with 100% efficiency. It is a simple, sustainable and inexpensive way to tackle the global water crisis, especially in developing countries.
Chunlei Guo, professor of optics at the University of Rochester.
During testing, the team found that the panel could reduce typical contaminants like detergents, dyes, urine, heavy metals and glycerin at levels that made the water safe to drink.
In addition, the device is easy to clean after use and can be reconfigured on the fly for optimum efficiency.
Also, since we use an open groove surface, it is very easy to clean by simply spraying it on. The biggest advantage is that the angle of the panels can be continuously adjusted so that they are directly facing the sun as it rises, and then move across the sky before setting – thus maximizing energy absorption. .
The research has been published in the journal Nature Sustainability, while the video below provides an overview of the device.