In the first evaluation of evaporation as a
renewable energy source, researchers at Columbia University find that
U.S. lakes and reservoirs could generate 325 gigawatts of power, nearly
70 percent of what the United States currently produces.
Though still limited to experiments in the lab, evaporation-harvested
power could in principle be made on demand, day or night, overcoming
the intermittency problems plaguing solar and wind energy. The
researchers' calculations are outlined in the Sept. issue of
Nature Communications.
"We have the technology to harness energy from wind, water and the
sun, but evaporation is just as powerful," says the study's senior
author Ozgur Sahin, a biophysicist at Columbia. "We can now put a number
on its potential."
Evaporation is nature's way of cycling water between land and air.
Sahin has previously shown how this basic process can be exploited to do
work. One machine developed in his lab, the so-called Evaporation
Engine, controls humidity with a shutter that opens and closes,
prompting bacterial spores to expand and contract. The spores'
contractions are transferred to a generator that makes electricity. The
current study was designed to test how much power this process could
theoretically produce.
One benefit of evaporation is that it can be generated only when
needed. Solar and wind power, by contrast, require batteries to supply
power when the sun isn't shining and wind isn't blowing. Batteries are
also expensive and require toxic materials to manufacture.
Read more here:
https://www.sciencedaily.com/releases/2017/09/170926125154.htm
Read the original Nature Comm article here:
Ahmet-Hamdi Cavusoglu, Xi Chen, Pierre Gentine, Ozgur Sahin.
Potential for natural evaporation as a reliable renewable energy resource.
Nature Communications, 2017; 8 (1)
DOI:
10.1038/s41467-017-00581-w
