Although evaporation as a renewable energy source still does not receive as much attention as solar or wind, its potential advantages are there. They have just been demonstrated by a team from Columbia University that has designed the technology necessary to take advantage of evaporation to obtain clean energy, in addition to measuring the possible use of it. The results are surprising: the lakes and swamps of the United States could generate 325 gigawatts, which represents almost 70% of the current production of the country.
But this advantage does not come alone. The system, according to Columbia University, would also lead to very important water savings ; as much as a fifth of what the US population consumes. This is possible because the researchers who have led this project estimate that around half of the water that is naturally lost from lakes and swamps through natural evaporation would be saved by applying an energy harvesting process.
Why do it? In addition to the expected production volume, because this renewable energy alternative could be used “on demand, day or night”, which would represent an important advantage over the intermittency problems of other sources, such as solar or wind .
Another strength of evaporation to start its takeoff in this field is that, by being able to generate energy only when necessary, it would make storage unnecessary and, with it, the provision of storage batteries. “Evaporation comes with a natural battery” , says Ahmed-Hamdi Cavusoglu, in charge of the study ‘Potential of natural evaporation as a renewable and reliable source of energy “, published in Nature Communications.
To provide its estimates, this research team has greatly simplified its model and has chosen to limit its calculations to the United States, excluding some areas. Likewise, it has been started from the assumption that the technology to collect the energy from evaporation is fully developed.
And in fact, in it are the researchers, who have already designed a team baptized as the Evaporation Engine. Equipped with a shutter that opens and closes and allows humidity control, this technology includes bacteria spores that expand and contract. That contraction is then transferred to a generator that produces the electricity.
The operation of the system is simple, according to the senior author of the study, Ozgur Sahin, in statements collected by Nexus Media, “When the blinds are closed, evaporation from the water surface raises the level of humidity under the blinds and spores they extend (…) their movement then opens the blinds, which reduces the humidity level. The cycle ends when the spores contract and close the blinds ” . And this process, which is repeated over and over again, ends up connecting with a generator that produces electricity.
For the moment, the researchers continue to work on this system to, once they improve its efficiency, test the concept in lakes, swamps and even greenhouses. In them, this technology could be very useful due to its double capacity to generate energy and save water. As work progresses, the prospects for the possible use of evaporation to produce clean energy without large-scale storage needs are immense.