Since the theoretical maximum efficiency for extracting power from wind is 59% (Betz law http://www.windpower.org/en/tour/wres/betz.htm) and the efficiency of a good turbine is approximately 42% at 5m/s and peaks at about 50% at around 8m/s there is still some room for improvement (though most of this loss is in the generator). In order to obtain the same amount of energy output at 5m/s as at 8m/s (with approximately 4 times the kinetic energy) the new design would not only have to disprove Betz law but would have to operate at 164% efficiency essentially drawing energy from somewhere other than the kinetic energy of the air.

Despite this I continue to hope that their work yields some benefits as I am getting tired of the number of renewable energy “breakthroughs” which receive all kinds of attention and do little or nothing to advance the technology

I thought you might appreciate a nite from WhalePower.

Steve Lapp is absolutely correct about the cube rule with respect to the power in the wind. But his interpretation of the test data is ill-considered: His error is his assumption that the efficiency of modern turbines is uniform across all wind speeds. It isn’t. Conventional low speed performance is still very poor, even for very large turbines. Small turbines are worse.

The gains from tubercle airfoils should not be guaged against maximum turbine efficiency in higher speed winds. Anybody and everybody gets power out of high speed winds. But there are very modern wind farms here in Ontario which are only producing abouy 22% of the “rated” or “nameplate” power. Good sites run about 27% max. That’s why a turbine that is rated at 2 MW actually delivers as little as a 450 kilowatt average on an annualized basis.

If you look at real power curves plotted against the Weibull distribution of actual wind speeds in a given location you’ll see that power production dives down faster than the power available in the wind at lower speeds. Wind’s Achilles heel is that power drops or stops when winds fall or fail.

There are severe limitations with conventional aerodynamics at low speed. Pitch has to be kept low to avoid damage during stall. Some of the really big turbines require such a large safety margin that they operate at maximum pitches at or below 7 degrees despite theoretical stall angles of 16 degrees or better. At low speeds and at low stall angles the lift-to-drag ratio gets less and less favorale and measured efficiencies are far below the optimum speed ,measurements which are typically used to report a turbine’s effieincy.

Our test results are a real world comparison. The stock turbine we employed gets 00.0 kW at 5 m/s while our blades boosted that to between 9.3 and 10.2 kW. The comparison Mr. Lapp proposes would interpret that to mean our turbine’s per centage improvement was infinite, which is absurd.

Simply put: WhalePower’s tubercle technology does not violate aeordynamics, just the claims of aerodynamicists who “knew” for decades that there was no per centage in making anything but a smooth knife-like leading edge. They were and are wrong: tubercles change the rules for low speed fluid flows in ways we have just begun to understand but are well documented in peer-reviewed articles in scientific journals.

The science is rock solid. Our engineering is real and effective. The old dogs are going to have to learn some new tricks. Of course they many give up what they “know” easily. Some won’t even enter the facts into their consciousness, preferring not to have to uproot and reformulate their understanding.

Finally, there is another point worth commenting on. May we encourage the various industry insiders who have ventured to comment on our business prospects without ever enquiring about our business plans to suspend too easy judgements. Our plans may be ambitious but we thinnk they are attainable. We really do plan to transform the world of wind energy but we do not expect to build and install the pieces ourselves. That’s what turbine manufacturers are for.

While we expect that adoption by the industry will be subject to the same kind of inertia as the science, we do believe we can license manufacturers world-wide and provide engineering services for their development of tubercle retrofits for any of their existing turbines as well as the tools for the development of a new generation of fully integrated tubercle blades.

We are confident that even major manufacturers will sign on and, after appropriate testing, will extend their warranties.

Thank you for your encouragement and support.

KEEP AN EYE OPUT FOR whalepower.com THE WHALE’S ABOUT TO BUST OUT OF THE GARAGE.

Stephen W. Dewar

VP Business Affairs & Acting Dir. of R&D

WhalePower Corporation

27 Tyrrel Avenue

Toronto, ON M6G 2G1

(tel) 416-651-7559 (fax) CALL FOR CONNECTION

stephen.dewar@whalepower.com

There’s a lot of VC floating around looking for promising energy companies. If the product really is as good as it claims (and I’m dubious because revolutionary claims in the clean energy field are a daily occurance) then people will be glad to spot them a hundred million to get things rolling.

cheers