Evaporation from lakes and reservoirs could provide nearly three quarters of America’s power needs, according to new research.

A team from Columbia University has published new research in Nature Communications which estimates that ‘evaporation-harvested power’ could provide 325 gigawatts – or 70% of the country’s energy. It is early days though, the potential at this point is confined to the lab.

“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.”

One of the technologies being developed to harness the game changing potential of evaporation is the ‘Evaporation Engine’ pioneered by Ozgur’s team. It works by triggering expansion and contraction in bacterial spores, with the corresponding energy  converted into electricity by a generator.

And a major plus for this type of energy is that it can be accessed on-demand, making it more reliable than wind and solar, which faces intermittency issues.

“Evaporation comes with a natural battery,” added study lead author, Ahmet-Hamdi Cavusoglu, a graduate student at Columbia. “You can make it your main source of power and draw on solar and wind when they’re available.”

The team is working to make its method more efficient before testing the concept out on a lake or reservoir.