David Schaefer hesitates to call his technology a kite. It’s modeled on the same concept — a lightweight sail or wing with a frame that’s tethered to the Earth — but in fact it’s much more.
Schaefer’s fiberglass and mylar skin kites produce energy as they swoop through figure-eights that peak hundreds of feet above the ground. Its tether wraps around a turning drum that’s connected to a generator that makes energy as the kite pulls against it, just as a child’s kite tugs in your hand on a windy afternoon.
But it’s a lot trickier to maneuver. This super smart kite is outfitted with GPS-guided flight controls, gyroscopic instruments and motors for moving the rudder and elevator flaps to guide its flight for maximum power production.
“It’s like trying to fly a bird that has a wounded wing,” said Schaefer, CEO of eWind Solutions. “It’s all over the place and it’s hard to keep under control.”
The kite is designed to climb just shy of 500 feet (anything above triggers restrictions from the Federal Aviation Administration). As it turns the drum, it can produce up to 45,000 kilowatt hours of power per year, enough to electrify a 40-acre farm or four or five houses. The device has a small footprint on the ground.
Schaefer and his wife Katie launched eWind Solutions more than six years ago to build the kites, which they also call a “tethered energy drone” or TED. Over that time, the Beaverton, Ore.-based company has raised nearly $1.7 million from the U.S. Department of Agriculture and state programs including VertueLab and Business Oregon Funds. They’ve put in an additional $400,000 of their own cash and last weekend traveled to Irvine, Calif. on a mission to raise another $1 to $4 million.
As concerns about climate change grow, interest in innovative ways to produce carbon-free power keeps expanding as well. Airborne energy taps into hard-to-reach winds high in the atmosphere where it blows more consistently and much stronger. The kites race along crosswinds that run perpendicular to the wind, something like a tacking sailboat, pushing them three to four times faster than the wind blows.
eWinds is talking to farmers, including vineyard owners, as potential customers. They plan to price the product around $55,000. By comparison, a small wind turbine costs about the same amount or more, but captures the wind at a lower elevation so it typically generates one-third the amount of power. A bonus feature is the kites create a hawk-like shadow on the ground, potentially scaring off grape- and nut-thieving birds.
“I think it’s really cool, and it’s challenging-to-do technology,” Schaefer said. “But it’s definitely a huge business opportunity, regardless of what you think about global warming.”
Getting hooked on kites
Eight years ago, when Schaefer was a director of engineering at Xerox, he was told to lay off 45 engineers. It was one of the hardest things he’d ever had to do. The next year he was asked to do it again. Instead, he took a voluntary severance.
Around that time, Schaefer stumbled across a short article about airborne wind energy in Popular Science magazine. His curiosity was piqued, and he unearthed a 1980 white paper about the technology by Miles Loyd. The seminal piece was titled “Crosswind Kite Power” and packed with equations on lift, drag and velocity.
After nearly 30 years in engineering at Xerox and IBM, the idea spoke to him.
“It was a challenging new field of green energy utilizing my engineering and product development background,” Schaefer said. “I was hooked.”
Schaefer and his wife launched eWind in their home, spending some of their savings to get it started. They joined an incubator, picked up two more co-founders and moved into a new space in Beaverton, west of Portland. The team, which has grown to five, built its own wind tunnel by souping up fans from Home Depot. They construct their kite prototypes from fiberglass and mylar skin; the final product will be made from carbon fiber.
In pursuit of the perfect kite, the eWind team crashed about three dozen drones in the early days of development.
“It can get really depressing,” Schaefer said. It takes a week-and-a-half or even two to make a new one. “Our success comes from not dwelling on the failures, and moving on.”
Airborne power takes flight globally
The airborne energy sector is getting traction in the U.S., but has a bigger following in Europe. There’s an active industry group and nearly four dozen European companies and universities are in the field, including Ampyx, EnerKite, KitePower and Twingtec.
In the U.S., there appear to be five companies in airborne wind energy and about as many universities supporting the sector. Two of the more established businesses are North Carolina’s Windlift and Makani, an endeavor that joined X, Alphabet’s secretive “moonshot factory.” Makani recently left X and is now a business within Alphabet, Google’s parent company.
Windlift and Makani, which both launched in 2006, are harnessing wind power in a different way than eWind. The Oregon startup’s kites are small and lightweight, weighing a maximum of 15 pounds, with a wingspan of 10-to-12 feet and a slender tether. Its power producing strategy is called “ground gen” as the energy is made on terra firma.
The technology used by Makani and Windlift is “sky gen.” The largest Makani kite stretches 85 feet across — close to the width of a commercial, twin-prop airplane. The kite carries eight spinning rotors on its wings, generating energy while airborne that is carried to the ground through a thicker, electrical cable. The device flies to a height of 1,000 feet, generating enough power for 300 homes.
Makani is looking to coastal communities as its target customer. This month the company announced that it has successfully completed autonomous, offshore flights of its kites on the coast of Norway. Makani is partnering with petrol giant Shell to engineer its small offshore platforms to which it tethers its kites.
“Once commercialized, Makani’s kites have the potential to bring power to hundreds of millions of people living along the world’s coastlines where the wind is strong and steady, but the water is too deep to fix wind turbines to the ocean floor,” wrote Makani CEO Fort Felker in a Medium post.
Windlift’s website calls out its “ongoing mission to support soldiers and reduce the enormous costs of remote military operations” through its technology, as well as serving disaster areas, isolated locations and farmland.
As eWind looks to grow, the startup recently partnered with iCFO Capital, a California-based company that helps businesses secure funding. Last weekend, Schaefer pitched to 20-to-25 investors at an iCFO organized event. Khris Thetsy, an iCFO managing director, said the company’s biggest challenge to success will be educating customers about the new technology, but he was enthusiastic about eWind’s innovations and the market potential.
“It fits our wheelhouse in terms of disruptive technology,” Thetsy said. “It’s a game changing idea.”Editor's Note: Funding for GeekWire's Impact Series is provided by the Singh Family Foundation in support of public service journalism. GeekWire editors and reporters operate independently and maintain full editorial control over the content.