Feed Laws

Large Wind Turbines

July 19, 2011
Paul Gipe

Honeywell Windtronics Update on Recommendation for 12 mph Sites

After posting my article Honeywell Windtronics WT6500 Report from the Field, the president of the company contacted me to note that their web site clearly says that they recommend using the turbine only at sites with a 12 mph average annual wind speed.

Though unsaid, the implication is that the buyer of the turbine, Lynn Shafer, doesn't live in an area with that wind speed and shouldn't expect the output on Windtronics' web site.

To be fair to Windtronics, I checked their web site and sure enough under Wind Energy Recommendations and FAQs it clearly states that "An average annual wind rating of 12 mph is recommended as a good minimum wind speed to keep in mind, off grid locations might consider less."

And just below this statement is another noting that "WindTronics has created a range of tools to assist in identifying proper site selection based on wind, rates and rebates."

The first tool was windknowldege that claimed to easily "look up US and Canada wind rates, electrical rates, rebates and incentives."

You can imagine what I did next, I clicked on it. What came up was Windtronics' wind estimator.

So, being the inquisitive sort, I put their wind estimator to the test for my home here in Bakersfield, California.

I put in my zip code, 93305, and put in my average electricity bill $30/month.

More Wind than I Thought

Boy, was I surprised--and embarrassed.

I am wind guy and I've been living in a wind energy gold mine for over 20 years and didn't even know it. I've always thought this was a lousy wind area. But no, the Windtronics estimator told me that the average wind speed was "good" at 11.2 mph. Yep, I fall within the recommended zone for one of their turbines. The low end mind you, but still within the "good" category.

Paying Less for Electricity than I Thought

Even better I learned that I was paying much less on my electricity bill than I was supposed to. I pay about $0.12/kWh because I am in the lowest tier of PG&E's rates. Windtronics said I should be paying $0.165/kWh. Wow. Don't tell PG&E.

Suitably chagrined that I didn't know the wind resource where I've been living for more than two decades, I decided to look up the wind speed myself.

Airport Data--Not the Best, But Handy

I am an old timer at this so I went to some old data sources that I used back in the days before computers--yes, that long ago. I found a NOAA web site that had airport data.

I am 15 minutes from the airport so that's close enough.

Now, I have written in many places that airport data is a lousy surrogate for real wind data at your site, but it was quick and it was "official". Whether it's right or not, I can't say. But I can say that there are no wind turbines down here at the bottom of the San Joaquin Valley and that should say something.

NOAA says BFL has an annual average of 6.4 over the past 50 years. Yes, you read that right, 50 years.

NOAA is a scientific organization and I just expected that they would be working in the metric system and 6.4 m/s is, well, "good" wind just like the Windtronics estimator said.

But I thought, to be on the safe side, I should check the units.

Whoa, it was in mph--not m/s. It was 6.4 mph!

Windtronics was telling me I had 11.2 mph, nearly twice as much.

Five Times the Power-Oh My

Now in wind energy, if you double the wind speed, you increase the power available eight times. In this case Windtronics was telling me that the power in the wind was 5.4 times greater than what has been measured at the airport for the past 50 years.

Ok, maybe the estimator works better in Michigan where Windtronics is based. Muskegon, on the shore of Lake Michigan came in at a reasonable number, but Lansing came in at 11.8 mph. The average annual wind speed at the airport in Lansing is about 10 mph. Still a big difference but not on the scale seen for my site.

Windtronics' estimator asks rhetorically, "If you agree this is a smart investment, this information will help you work smarter with Windtronics, and learn about ways to make the system work its best for you!"

The web site very carefully does not say, "this is a smart investment". It asks a rhetorical question, "If you agree". The casual reader will not typically catch such subtlety.

The estimator goes on to report that if I buy one of their $9,500 wind turbines, I will get 2/3 of my cost back in various subsidies. Lots of people shop bargains, and this makes the turbine look like a bargain. (For what I think of these subsidies, see Capital Subsidies Are Not Good Public Policy.)

Windtronics tells me that the turbine will "breakeven" in 12 years.

And Windtronics' web site just keeps piling on the claims.

Windtronics says I'll save $261 per year. That implies their turbine will generate 1,600 kWh per year here in Bakersfield. It's extremely unlikely that the Honeywell Windtronics WT6500 will produce that much electricity at the Wulf Test Field in the Tehachapi Pass where there is real wind.

What does it all mean?

It means that a disgruntled customer could charge Windtronics with deceptive and misleading advertising.

The case would be hard to prove because Windtronics' estimator has all the qualifications one would expect.

The biggest is that the estimator provides wind speeds at 50 m hub heights. Yes, that's right, 164 feet above the ground. But the estimator then adjusts the wind speed for the 14 m (45 feet) tower height Windtronics recommends using the 1/7 power law. This calculation is hidden from view. What is presented is the wind speed at 50 m.

The impression left with the casual reader is that the wind speed presented at 50 m is the wind speed they will get at the height of the turbine even though the paragraph before the results box clearly says this estimate is for a 50 m height.

Windtronics says, at the very end of all the footnotes, that the average speed at my site is 8.8 mph. It is still substantially more than the airport data, but "only" 2.6 times the power in the wind at the airport.

A state's attorney general would have to prove that Windtronics intentionally presented the higher wind speed, the speed at a 50 m height and buried the estimated speed at the height of the turbine at the end of the footnotes to deceive buyers. They could only do so if they found incriminating evidence, for example, in electronic correspondence. Otherwise, this is a simple mistake and Windtronics could be asked to correct it.

In the end, it could actually all be a simple mistake that Windtronics will eventually correct. Meanwhile, they are marketing and selling $9,500 wind turbines--and taxpayers are picking up a big part of the tab.

What are the lessons here?

As I've written many times before,

  • Don't believe everything you read,
  • Always read the fine print,
  • Never rely on web-based calculators where calculations are hidden from view, and
  • Always do your own calculations.

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