Ntl Geo: Helix Collapse Fails to Crush Hope for VAWT

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Helix Collapse Fails to Crush Hope for Vertical Wind Turbines
Brian Clark Howard
For National Geographic News
Published August 20, 2012

With graceful, sail-like blades that turned in the wind like white corkscrews, Helix Wind's vertical axis wind turbines (VAWTs) captured the imagination of bloggers and the tech press in 2007. The San Diego-based company developed a polished website and at the height of its promise, delivered two of its turbines to the Nevada desert for the annual arts and self-reliance festival, Burning Man, in 2007. The Helix turbine whirred above the vegetable-oil-fueled art cars and recycled sculptures.

The gyre ceased on May 11, when Helix Wind was forced to auction off all its assets. Another vertical wind turbine company, Sauer Energy of Newbury Park, California, purchased all that remained of Helix that same day—paying just $25,000 for hard assets and $1.5 million for the company's intellectual property, and announced plans to operate the brand as a new division.

Sauer Energy, which itself is $2.5 million in the red, according to filings with federal securities regulators, did not respond to a request for comment. But in a statement at the time of the purchase, Dieter Sauer, the company's chief executive, said his firm was interested in acquiring Helix's unique turbine designs and proprietary monitoring software. He added that Sauer would not assume any of Helix's liabilities. Sauer Energy has been designing its own small VAWT called the WindCharger, which has yet to be released.

But another firm that has risen from Helix's ashes is writing the next chapter in vertical axis wind technology. Venger Wind, started by Helix founder Kenneth Morgan, whose acrimonious split from the firm ended in litigation, has now picked up some of Helix's contracts, including a high-profile installation on the Philadelphia Eagles' NFL stadium.

Morgan told National Geographic News that the experience at Helix left him feeling "betrayed." He said, "It essentially destroyed the company. It almost destroyed the industry for vertical axis wind turbines. It was pretty sad."


Doubts for Vertical

Although Helix Wind had received a considerable amount of positive press, the company's filings to government investment regulators told a story of financial woes. In September 2010 Helix reported $41.7 million in debt and negative cash flow.

When the news of Helix Wind's demise broke in April, critics of vertical axis wind turbines pounced. "I doubt there are any assets there worth anything," small wind consultant and author Paul Gipe told National Geographic News about the impending auction. Gipe and other critics argue that vertical turbines are inherently inefficient compared to the horizontal turbines that dominate the market. They say the very aspect that lends vertical turbines their appeal—their compact, "rooftop" size—further erodes their already small potential for performance, as proximity to buildings cuts down wind flow.

"Why do we keep repeating the same mistakes?" asked small wind turbine builder and author Ian Woofenden. "No vertical axis company has survived in the marketplace for any length of time. All long-term successful wind-electric manufacturers use horizontal axis designs. This is because they work."

Woofenden added that he is "baffled" by all the recent attention given to VAWTs by venture capitalists, inventors, and the media—all ignoring the warnings of "longtime experts in the industry." He added, "Making a viable wind turbine is a very difficult job. Starting out with a flawed design and flawed assumptions virtually guarantees failure. All of this is a distraction from the real wind industry, and a waste of resources."

Both the Helix Wind design and Sauer's WindCharger are considered "Savonius-style" vertical axis turbines, named for Sigurd J. Savonius, the Finnish engineer who invented the form in 1922. The turbines have scoops, or aerofoils, arranged around a vertical shaft, and they are turned by the wind.

Unlike most modern wind turbine blades, the scoops do not generate lift, so they can go only as fast as the wind. That's a hindrance because, in general, the faster the blades turn, the more energy a turbine can harvest from the wind. As a result, Savonius wind turbines are said to have much lower efficiency than most horizontal axis wind turbines (HAWTs), or advanced VAWTs like the Darrieus rotor, which resembles an egg beater with its twisted blades that generate lift.

Proponents of VAWTs often say they offer certain benefits over HAWTs, although industry insiders like Gipe and Woofenden say many of those claims don't hold up to scrutiny. Gipe and Woofenden said that, contrary to VAWT marketing materials, there is no scientific evidence that they are any safer for birds or bats. (They also point out that the entire wind industry is so diminutive compared to the rest of our built environment that it poses a relatively tiny threat to wildlife.)

Gipe said it is misleading for makers of VAWTs to tout their product as performing well in turbulence or having "low cut-in speeds." Turbulence robs the wind of recoverable energy, he said, and there is very little harvestable energy in low wind speeds because energy increases with wind velocity.

Small wind turbine designer Hugh Piggott said he objected to Helix Wind advertising its products for rooftop installations. "The wind resource on urban rooftops is generally quite poor," Piggott wrote in a recent blog post. [A Helix turbine] is a nice ornament, but at $17,500 it's well overpriced."


Venger Forges Ahead

The drama inside Helix's offices began long before the company's demise. In March 2010, founder Morgan settled a pair of lawsuits with the company and its then-CEO Scott Weinbrandt for $150,000. Weinbrandt declined to comment for this article.

Morgan then started a new venture, Venger Wind, a privately held company based in Thailand. Morgan told National Geographic News he rehired a number of engineers from his old firm to develop a new version of the Savonius VAWT. In April, the company announced it has patent-pending status for its design.

"We've decreased its drag coefficient significantly," said Morgan. "We're going to push the Savonious to the outmost limits possible." (That will still pale in comparison to the efficiency of most HAWTs.)

Morgan criticized his former coworkers at Helix for "indiscriminately selling turbines to anyone without any feedback or guidance." He said some buyers were "interested in 'greenwashing.' " As an example, he said one client insisted on putting a turbine on the front of its building so it would be highly visible, even though prevailing winds dictated that it would perform better on the back side. "It's crazy," said Morgan. Companies buying vertical wind turbines often rush into the decision with overly optimistic expectations, "but once the romance is over," he said, "the accountants and CFOs are asking, 'What's my payback?'"

Morgan said Venger Wind is taking a different approach, by stressing that a site's wind regime is critical to energy production. "We won't touch many markets because there is not good wind," he said. Morgan added that he is putting his distributors through training that includes emphasis on using anemometry, the study of wind force and velocity, to study actual current patterns at prospective sites.

Morgan said he expects that customers could see a payback in five to ten years, if they have sufficient wind. (Experience shows that "if" is critical.) Morgan added that his engineers are adding computer-driven active controls to increase efficiency, something the Helix design lacked.


Eagles Project Still Soars

Venger Wind has picked up some of Helix's outstanding contracts, including providing 16 turbines to Oklahoma Medical Research Foundation and 14 turbines to the Philadelphia Eagles, who will soon be mounting them as part of a $30 million plan to "green" Lincoln Financial Field. With solar panels and a biofuel cogeneration plant, the Eagles hope to generate 1 billion kilowatt-hours of clean electricity over the next two decades, making it the first team to provide all its own power locally.

According to Rob Zeiger, senior vice president of communications for the Eagles, Helix's demise did not impact the team's time frame for the green project because Venger was able to step in. "We've been very pleased with the reaction from the community to build the NFL's greenest facility," Zeiger said. "Everyone wants to know when the turbines are going up," he said. (Answer: By the end of this coming season, he said).

Zeiger said seven turbines would be placed at each end zone, where they will be highly visible. "Our goal is to show our commitment to green, but our real goal is to get fans to see how they can put this to work in their homes."

Zeiger explained that the Eagles recently downgraded their order of turbines to 14 from as many as 80, after more careful study indicated installing them on other parts of the stadium could cause shading of the playing field, which could "interfere with catching passes."

It's too early to say how much energy Venger turbines will actually produce, though physics dictates that it will be less than a similar-sized horizontal wind turbine. Zeiger said he knows the "workhorse" of the Eagles' project will be solar panels. At this installation and elsewhere, vertical wind turbines are valued as much for their ability to turn heads as to turn nature's forces into kilowatt-hours.

"The turbines will contribute somewhat and are there to remind people visually that there are multiple green ways to get your energy." Zeiger added, "Just think of those blimp shots. The turbines are going to be visible."

Brian Clark Howard is the co-author of Build Your Own Small Wind Power System.


http://news.nationalgeographic.com/news/energy/2012/08/120820-helix-wind-collapse/
 
If you want to generate electricity with wind, high RPMs are especially vital. The main problem with a Vertical-Axis-Wind-Turbine is that when wind pressure begins building in front of them, then above that wind-speed, any extra wind will simply go around the VAWT instead of through it. If you must use a VAWT, you may be limited to generating lower voltages (12V, maybe 24V?). The national grid needs thousands of volts, and most home off-grid systems use a 48V system.

Per dollar invested, the well-known 3-blade turbine works best for generating electricity (there is an argument for a 5-blade in lower winds. Starts generating at a lower wind-speed, at the price of losing some of the higher wind generation). The problem with them is that they typically need to be at least 60-feet high to harvest significantly more wind than if its mounted lower. The first step is to mount a data-logging pole on your proposed site, to find the lowest elevation where significant wind is available. Finding that height, and also the average speed of your sites prevailing wind, are vital to selecting a system that will perform as advertised.

You cannot mount a wind-generator of any significant size to a house. Your insurance will require you to mount it on a tower that is located far enough away from the house to have a safe "fall circle" (if you even have enough land for that). If you want to try out wind generators, but you can't afford a tall tower with a 3-blade turbine (or you are not allowed to have a tall tower), you can build an efficient Lenz2 that's mounted near the ground, like this:

L2_flying.JPG


I am a fan of VAWTs, but they are a poor second choice for generating electricity. If you must try one, you might add a cars timing belt and pulleys (from a salvage yard) to make a cheap 1:2 gear-up. They have good low-RPM torque, and work well for compressing 100-PSI air, and also for pumping water. The main benefit of a VAWT for generating electricity is that...poorly as they may perform, they are allowed in cities...specifically because of their lower RPMs.
 
spinningmagnets said:
...(VAWTs) but they are a poor second choice for generating electricity...

I have seen credentialed studies by government agencies that are posted on the net that all WTs and particularly VAWTs that are in the ground boundary layer are non starters economically. What works is large, utility grade HWT's as far up as the tower will go. This stuff makes a good hobby, but not economic homestead power.

PV is the most viable homestead solution in my book.
 
bigmoose said:
spinningmagnets said:
...(VAWTs) but they are a poor second choice for generating electricity...

I have seen credentialed studies by government agencies that are posted on the net that all WTs and particularly VAWTs that are in the ground boundary layer are non starters economically. What works is large, utility grade HWT's as far up as the tower will go. This stuff makes a good hobby, but not economic homestead power.

PV is the most viable homestead solution in my book.


A home backup power generator is never going to reach an ROI pay back either.
Yet, they are popular because it provides a small amount of self sufficiency and independence.

My home averages 3kwhr per day. I think it would be pretty easy to achieve this with a small wind turbine and a battery bank. My ROI might not make sense, but the intangible of being independent of the electric grid is worth something to me.
 
I would also be suspect of any government sponsored study who's finding encourage folks to not deviate from continued dependency on state controlled power grids.

If folks had there own power and water supply, they would not feel nearly as helpless.
 
I have a friend in Wisconsin that runs his total electric house on Wind Turbines and some Solar panels. Yes, he has a standby Generator, that does kick on when his wife is running the Electric dryer and the New electric range, and the electric water heater, AND the well pump kicks on. Has to get past the uumpf of starting the pump motor.

Has NO connection to the grid. Builds and sells Wind Turbines. Has a really nice rack of batteries, and, says he may never get back his investment, BUT, selling turbines has helped a little.

Link if anyone is interested.
 
Luke, my replies were based on research I did about two or three years ago for my best friend and business partner. He wanted to import German VAWT's and small HAWT's, and as usual, I was tasked with generating the business case... He (we) had a high probability of making some cash on the deal; but I wouldn't sign on, as I considered their siting software estimates way, way too optimistic. For example they often referenced 12 to 14 mph winds, but the site surveys in the boundary layer averaged 3.5 to 4.5 mph... and the degredation is not linear either! I made the case and he immediately also refused to sell an item that we had to "distort" the payback to make the case. They were well built units, but the ROI does not make any sense.

As you said, there are other reasons that people invest in things, technologies and dreams. No problem there.

Right now for economic ROI I am seeing is in diesel gen sets, run on about 15% diesel and the remainder port injected natural gas... Not emissions free, not independent of all utilities, but meets ROI.
 
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