Maps of power generation from natural evaporation and water savings. a Maximum power density available and b total decrease in evaporation rate due to power harvesting potentially available from open water surfaces across the contiguous United States of America. Maps calculated using the data 22 across 934 weather stations to calculate W Max and corresponding ΔE at each location from eq. (3) with natural neighbor interpolation and linear extrapolation to generate a 5′ resolution map
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 referenced above.
"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."
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.
Desert areas could be covered with pumped seawater or brackish underground water to maximize evaporation power production potential.
Mineral extraction from the waters of the Great Salt Lake can serve as a evaporative power plant.