Kuppers says that CFRP provided other advantages, too. The 0/90 degree fiber orientation provided bending rigidity as well as torsional flex. Future versions will have ±45º fibers for a stiffer torsional response. This design enables passive blade feathering at high wind speeds, mitigating the dangers associated with extreme wind. “That [kind of customization] is something you can only do with composites,” asserts Kuppers. “You could never do something like that with aluminum.”

The CFRP blades, which are wider than typical turbine blades, are also strikingly lighter. Each aluminum blade in the first prototype weighed approximately 8 to 10 pounds, while the CFRP blades in the latest prototype are 2.4 pounds. The lighter, wider blades can capture low winds that other small wind turbines cannot. “That really helped with the price-per-performance metric,” says Kuppers. “The blades could have even been more expensive than aluminum and still have been worthwhile in terms of dollar per kilowatt hour.”

Reduced costs are imperative if DTI is to succeed in making a commercial small wind turbine. According to Visser, purchasing a small wind turbine today to power the average homeowner usage of 10,000 to 20,000 kilowatts per year costs between $75,000 and $80,000 installed. “Who’s going to shell out that kind of money?” he asks. He estimates that the DTI turbine will sell for around $24,000, and two of them would be sufficient to power the average home. Thanks to its ducted design and other features, the wind turbine is also expected to generate twice as much energy as a regular open-rotor turbine of the same size, says Visser.

DTI expected to complete installation of the CFRP-bladed turbine on the roof of Clarkson University’s Blade Test Facility this winter. Once mounted, the team planned to measure energy generation, noise and vibration levels, and blade performance. “If it performs like it should then the only [issue] would be total system cost,” says Visser.

Casey Hoffman, CEO and co-founder of Vistex, is optimistic. “I think a lot of people have this preconceived notion that composites are so expensive and there’s no way they can afford it,” he says. “But with our technology, we’re really finding that we can help customers realize that these materials are not out of the realm of possibility.”

It will be a while before consumers can purchase a DTI turbine. Visser and Kuppers say that additional CFRP prototypes may be needed. Once the design and materials are finalized, the turbine will be tested for nearly a year by the Small Wind Certification Council (SWCC) to obtain certification, which is important because it enables consumers to receive federal and state incentives. In New York, such incentives could reduce the cost of the turbine to under $5,000. “I can’t think of too many people who wouldn’t take advantage of that,” concludes Visser.