A startup company in Chaska aims to turn wind power upside down.
Instead of putting turbines high atop towers, SheerWind's unconventional idea is to scoop wind from above and channel it to ground-level turbines, a design it hopes will be cheaper.
The company recently began testing its first pilot-scale "Invelox Wind Delivery System," a 60-foot-tall wind collector that slightly resembles a municipal water tower.
At its top is a multidirectional air scoop that feeds wind into fabric ductwork and a turbine to generate electricity. The turbine blades spin inside the ductwork.
The technology has moved beyond the lab and now faces a key test of technological credibility. The company also faces dual needs for capital and customers.
"Anytime you come with something so drastic, it is difficult," said Daryoush Allaei, CEO of SheerWind, which began testing the unit last month.
Allaei, a mechanical engineer with several patents to his credit, said he believes his invention can deliver "significantly more output" compared to conventional turbines -- and at lower wind speeds. He said testing has not progressed to the point of proving that's happening on the unit built next to its offices in Chaska.
Testing system is key
The heart of the technology is the wind collector and ductwork.
The generator used in the unit now being tested is a small, off-the-shelf model that can be purchased through hardware stores for residential rooftops. Its maximum output is 1,500 watts, enough to run a couple of toasters -- and a fraction of the output of conventional wind turbines that generate 1.5 million watts or more. SheerWind eventually plans to offer bigger units.
When Allaei showed the Invelox system to the Star Tribune last week, workers were making adjustments to the ductwork and the generating unit produced almost no power.
One question is whether the extra cost of building the tower, air scoop and duct system is justified by greater output from the turbine. Otherwise, it might be cheaper to mount the turbine on a tower and operate it conventionally.
Palmer Carlin, a senior engineer at the National Wind Technology Center, a federal turbine-research facility outside Boulder, Colo., said that question could be answered by measuring wind speed into the Invelox and its resulting power output, and comparing those performance measurements to the wind speed and output of the same turbine mounted on a tower.
"That would be the first thing I would look at," said Carlin, who reviewed SheerWind's published specifications and marketing materials at the request of the Star Tribune.
Allaei said the Invelox technology benefits from the "Venturi Effect," which causes air to increase velocity when forced through a narrow tube. This effect explains the strong, canyon-like winds amid tall urban office buildings.
Among the Invelox's other expected benefits, Allaei said, are less annoyance to neighbors from blade noise and light flicker and less risk of bird deaths. He also said towers won't need to be as high as conventional wind turbines.
He said Invelox is the first technology to capture wind and channel it to a ground generator. Other companies have added shrouds to boost performance of rooftop wind turbines. In the 1920s, a 70-foot-long ducted wind turbine nicknamed the "blunderbuss" was built in the California mountains, but it didn't survive that inventor's financial downfall, according to Robert W. Righter's book "Wind Energy in America: A History."
Allaei has a long record of inventing things, including a material-screening technology that in the mid-2000s went into commercial production in Chisholm, Minn., for the iron-mining industry. That venture, Smart Screen Systems, is no longer in business, but Allaei said other companies are interested in the patented technology to screen fine materials.
Allaei said he spun off SheerWind 18 months ago from his research and consulting company, QRDc Inc., also based in Chaska. SheerWind has five employees and 16 individual investors and five partner vendors that contributed services for a stake in the company, he said. About $1.7 million has been raised so far, he added.
One SheerWind investor and executive is Cynthia Lesher, retired president and CEO of Xcel Energy's Minnesota region operations. Xcel's former Chairman James J. Howard III also serves on SheerWind's board.
SheerWind hopes to sell portable units that could furnish emergency power along with larger models that could be part of community wind farms, and eventually giant, utility-scale versions. Allaei believes wind-capture technology and generators also could be incorporated into buildings.
"Nobody has been able to go in the middle of downtown and put in a wind turbine," he said. "We can."
David Shaffer • 612-673-7090 • @ShafferStrib