The Quest for Vertical Axis Wind Turbines Despite Failures

Source: By Robynne Boyd, Scientific American • Posted: Wednesday, January 30, 2013

A small-scale vertical axis wind turbine designed by Wing Power Energy. Image: courtesy of WPE

The vision is beautiful, if not somewhat tried: a large cluster of 360 foot tall towers encircled with long, slightly cupped blades, similar to airplane wings, spinning in the wind like a wind vane. The result? An outpouring of clean electricity at the Megawatt (MW) scale.

That’s what Harry Ruda, CEO of Wing Power Energy, a small vertical axis wind turbine (VAWT) company, sees when he imagines his turbines coming of age. He’s one of the believers out there gallantly chasing the dream of making VAWTS big.

Currently, his 2-kilowatt capacity turbines stand 34 feet tall. However diminutive (both in terms of height and output), Ruda believes these turbines are the blueprint for the next generation of wind energy, that when scaled up, will revamp wind power at the utility level, ushering in wind 3.0.

The quest to slay the faulty dragon of conventional, or horizontal axis, wind turbines (HAWTS) has been an impossible one, thus far. The domination of conventional wind comes from their reliability, efficiency and increasingly low cost, despite vertical’s touted improvements – less expensive to build and maintain, safer for birds and bats, quieter, and their ability to use less open space.

“VAWTs are a perfectly legitimate technology, but these are not toys or lawn ornaments,” enthuses Paul Gipe, a renewable energy advocate and analyst, who’s worked in the industry for over 30 years, “They are supposed to produce electricity, and must compete with all the other machines that produce electricity. Right now, no one produces a VAWT that is more cost effective than a conventional wind turbine.”

There are enough examples of VAWT failure to solidify this air of doubt. According to Gipe, in California in the 1980s, hundreds of VAWTs were in operation producing millions of kilowatt-hours of electricity each year. Those turbines were not cost effective and were less reliable, as evidenced by their aluminum blades weakening and flying off after operating for several hundreds of hours (Eeeek!). Not one of these turbines is operating today.

More recently, a handful of small startups have tried to take up the cause. Helix Wind, a company that seemed to be heading in the right direction, ended its run due to financial troubles. Another, Windspire Energy, received accolades for its streamline design, was promoted in Popular Science’s “Best of What’s New” in 2008, and then declared Chapter 11 last year when it lost huge amounts of funds while repairing unreliable parts under warranty.

The problem, says John O. Dabiri, the Director for the Center for Bioinspired Wind Energy, California Institute of Technology, is that even though multiple companies are premiering new design developments like improved efficiency of 10-15%, they’ve still ignored the Achilles heal of vertical axis wind – fees and functionality.

“The main goal should be to change the cost and reliability of the designs, not its efficiency,” said Dabiri. “If a 2kw turbine costs more than $5,000.00 the company is blowing smoke about its viability.”

This means a turbine would have to be in the range of $1-$2 per kilowatt of maximum power production, and about 5 cents/kwh of electricity to get anywhere close to being competitive with the current fossil fuel market. It would also have to operate smoothly for about 20 years.

If this $5,000 cost point is the measure of success, Wing Energy’s current turbine isn’t likely to make headlines soon their small turbine sells for about $10,000. The Economies of scale bear much of this blame, since until a product is mass-produced, it’s difficult to keep manufacturing, installation, and distribution costs low. However, so too is the material choice.

“We do think there’s a lot of promise for VAWTs,” said Dabiri speaking on the future, but added that the [designers] need to start by using the right materials for small turbines before trying their hand at large wind.”

It’s this sliver of hope that keeps companies trying, including Venger Wind, Wepower Eco, and Urban Green Energy. This is the list that Wing Power wants to best with their turbine that combines the savonius and darrieus design into one technology, allowing it to operate very efficiently in low and high wind speed. This design is already being utilized on the micro wind scale to further the reach of cellphones.

“We believe that verticals will ultimately rule the day and replace horizontals because of their innate benefits,” says Ruda pitching his concept. “One of our missions is to prove this theory by starting with modeling 100 kilowatt capacity turbines and then moving to megawatt.”