Dust devils are swirling micro-tornadoes that pop up regularly in dry, warm climates or during the summertime. Researchers say they have figured out how to tame the tiny twisters and extract their energy using a rotating turbine blade.
A team at Georgia Tech has built a small demonstration prototype about three feet wide. It looks like the inside of an aircraft engine rotor turned on its side. Warm air flows in through a series of vanes that force the buoyant ground-heated air to rotate as it rises.
This spinning creates a powerful vortex, or "dust devil," according to Ari Glezer, the principal investigator and professor of mechanical engineering at Georgia Tech. As the column of air rises, it draws in more hot air to keep going.
Here's a video of a laboratory-created dust devil.
And the real thing at a baseball field in Indiana.
"We trigger a vortex artificially," Glezer said. "The idea is to ultimately hook it up to the electric grid."
Glezer's project recently was awarded $3.7 million from the Department of Energy's Advanced Research Projects Agency -- Energy (ARPA-E). The Solar Vortex fits with the goals of ARPA-E to find high-risk, high-reward projects, according to program director Bryan Willson.
"It's part of our mission to look for disruptive energy technologies that are typically earlier stage and higher risk than other agencies or commercial entities would take on," Willson said. "They also have to be based on sound science."
Glezer said if the Solar Vortex is successful, it would cost 25 percent less than traditional wind power generation and 60 percent less than solar panels. That's because the vortex is generated with or without prevailing winds higher up in the atmosphere. The other nice thing is the turbines are low to the ground and don't block neighbors views, something that has stymied wind projects in several parts of the country.
Glezer says he envisions an one-kilometer square array of turbines that are six feet tall and 30 feet wide. He believes they could especially be helpful during the summertime, when demand for electricity spikes He also sees them sitting atop rooftops on office buildings and factories where there is plenty of waste heat escaping to the air.
Nobody has harnessed dust devils before, and Willson said some of his fellow DOE managers needed some convincing before the agency agreed to spend taxpayers' money on it.
"It's definitely an unconventional technology," Willson said. "Which means we put it through a lot of internal debate at ARPA-E to make sure it was a rational technology, as well as just being cool and innovative."