Deborah Storey For AL.com
After five days without power in North Alabama following the 2011 tornadoes, one man was inspired to invent what could be a revolutionary green power source that captures wind.
Robert Yost was sitting on his deck in Huntsville with his wife during the outage. She looked at a fan spinning in the breeze and asked why you couldn't power a house that way.
Yost — whose 40 years of aerodynamics and manufacturing experience at GE, Boeing and Pratt & Whitney included designing jet engines — wondered, too. He began studying wind turbines and invented a small "cube" that converts wind power to electricity. His Huntsville company, American Wind, is now manufacturing units for customers that include the U.S. government and distributors in Japan, Mexico and South Korea.
American Wind's MicroCube, which measures 9-by-9-by-13 inches and weighs about 9 pounds, is designed more like a jet engine than a traditional wind turbine.
American Wind's MicroCube is the building block for a system that captures wind to create energy.
"He knew to optimally design a wind turbine, if you made the thing bigger and bigger you are getting more energy but you are increasing how much energy you lose," explained his son, Daniel Yost, company vice president of marketing. A bigger car takes more energy to move, for example. "He knew he had to make it small."
The first prototype was too small. The device 3-D printed at Huntsville's Inergi Inc. was 4 inches wide and too tiny to work on. Tools wouldn't fit in it, Yost explained, so they made it bigger — but not much.
Design specifics are secret, of course, but basically MicroCube's generator captures 98 percent of wind energy vs. roughly 35 percent for a traditional generator. The units are quieter, too. The 3-D printed cube includes neodymium magnets, just under 4,000 feet of wire, 11 blades and special ducting in a portable unit marketed as safe for the environment and wildlife.
"In 100 years no one has developed a generator like ours," Yost said. "It gives it a very unique ability and it's virtually frictionless. We actually have a statement from the patent office that calls it the first change in alternator design since (inventor Nikola) Tesla."
The blades, framing and control boxes are made from a proprietary resin as strong as steel but remarkably light. AT2LAS, a patented non-corroding material manufactured by Advanced Aerospace Tooling of Huntsville, weighs 40 percent less than aluminum and 80 percent less than steel. Lighter is better for the MicroCube because the idea is to install them in groups on rooftops, trailers, power poles or cell phone towers, or as wind-capturing walls.
Robert Grigsby is owner of Advance Aerospace Tooling and Advanced American Technologies of Oak Ridge, Tennessee, and Huntsville.
He predicts American Wind's wind-driven electric generator "will very likely be recognized as producing the greatest innovation to electrical power generation in the last century.
"Given that the MicroCube is no larger than your average toaster and generates a nominal 1 kilowatt of electricity that can be stored on-board, American Wind brings the promise of renewable energy to all corners of the world," Grigsby said.
American Wind's multi-blade cubes work together. The number required depends on power needs. A TriCube is three connected cubes. Fifty MicroCubes combine in a WindWall that "will create a vast amount of power," Yost said. The 10-foot-tall Advanced WindWall uses 100 MicroCubes to produce 100 kilowatts at maximum power.
"We take a single cube, put it into a wall of cubes, even at low wind speeds we can still produced a significant amount of power," said inventor Robert Yost. "The power of many, as we like to call it, comes into effect."
The Advanced WindWall is an advanced turbine system that contains 100 wind-capturing "cubes."
"Traditional wind turbines rely on sweep area. It's all about how big it is," said Daniel Yost.
The MicroCube generates power from breezes as subtle as 1.5 miles per hour — "not a lot, but there's some," said Yost. "When we get up to 35 or 40 miles per hour we start to get near our peak of 1 kilowatt. We call that our optimal range." Big wind turbines work in the 15-40 mph range.
MicroCubes are designed for wind up to 140 mph — at least. The company tested the product to 140 in two wind tunnels and it didn't fail. A California test next year will subject it to 300 mph winds. Because of the frictionless design, high wind isn't expected to cause the unit to overheat and explode.
"When Hurricane Florence came through there wasn't a wind speed our turbines couldn't handle," said Yost.
"We need to know what the failure point is. We know in most everyday scenarios there's not a failure point, even in category 3 hurricanes. But what about a category 5 tornado? What's it going to do? We're going to test it for those winds. We don't anticipate it failing."
Huntsville residents will be seeing WindWalls in use in the next few weeks. The first installation in the city will harness power from six Advanced WindWalls to power a section of a business. Yost can't disclose where yet but "you will see it when you drive every day."
"Our product is so different a lot of people don't believe in it until they see it. People don't believe that it works until we take it to them and show them," he said.
"We can produce a lot more power in a smaller space. It comes back to the original story. Robert designed this for himself. It's meant to use right at the point of use. Our motto is 'Power to the People.' We mean it very literally."
For businesses on coastlines, for example, "instead of having to have a nuclear power plant 200 miles inland, where you have 200 miles of transmission loss, why not use those gale-force winds and put the power right there."
Because a MicroCube starts working with just a light breeze it can be used in parts of the world where winds are variable — like Alabama. The Southeast "has the worst wind speeds in the country," Yost said, and low cloud cover that can affect the efficiency of solar power.
"Seventy percent of the United States sits right here in these wind speeds," he explained. "If you can't serve these wind speeds what's the point of putting them out? We can service the entire range of wind speeds from 1.5 to over, we say, 65."
Complete redesign
The small wind-capturing turbine is not a new concept. There's even a wind cube on the market. Most designs just change the blades.
"They don't realize the generator is what's broke," said Yost. "It was the marrying them that's what's different.
"It's the combination of all the different things that we did that creates that difference in our product," he said. The alternator and wind turbine design are patented. "It's not a single thing we did. It's multiple things we did."
Robert Yost tilts traditional windmill power thinking on its head by changing not only size and materials but blade arrangement.
"The way Robert developed these blades, they're affecting each other in a positive relationship," Daniel Yost said. "One blade is capturing the air on the front side, and on the back side it's reducing its pressure so we can put more blades in a smaller space."
The company's marketing priority right now is commercial use. Residential sales will come later. Homes would need a smart controller, plus battery storage similar to solar systems. One microcube costs $2,850 and has an expected 30-year life span. Greater production volume should bring prices down, they say. The inventor plans to install them at his own house next year.
An average home would need about 16 MicroCubes depending on the area.
"My vision for this product is power for people that don't have it," said company president Robert Yost. "There are so many places here in the United States and around the globe that they can't afford to have electricity. You've got to produce it for cheaper. You've got to stay out of environmental hazards. There's not a single piece of material in our product that's environmentally hazardous."
American Wind held a military exercise this summer where the Tricube charged a large battery bank. The oil industry is looking at the technology for offshore rigs. Another design called the Portable Energy Power Source, or PEPS, has been engineered to provide power anywhere in the world for military or post-disaster use. The 120-inch tall grid of cubes on a trailer rises 30 feet to capture wind. In parts of the world with "dirty power" — high and low spikes — the PEPS should even it out so it won't harm equipment.
But what happens when the wind doesn't blow? "Nothing," said Daniel Yost. "A zero wind we don't see too often" in Alabama, but wind speed fluctuations are accounted for. Power can be stored in batteries or placed back into the grid and sold to the utility company.
American Wind's 12 employees are building product for large orders coming in, said Yost. The minimum investment for individuals is $25,000.
MicroCubes aren't capturing Alabama breezes yet at the company offices on Blake Bottom Road because the priority is to sell them. Robert Yost said it won't be long, though, before the little white boxes power American Wind's whole operation.
"About 18 months from now this facility will be totally off the grid," he predicted.