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Rochester, NY – December 2, 2009 –<\/strong><\/em><\/p>\n WindTamer Corporation (OTC.BB.WNDT-News) today released the results of a performance report from Professor Kenneth Visser of the Department of Mechanical and Aeronautical Engineering at Clarkson University in Potsdam, New York. The report is based on an analysis of field testing in the Geneseo, New York area and numerical modeling at the Clarkson University.<\/strong><\/em> William A. Schmitz, President of WindTamer Corporation, said that, “From a sales and marketing point of view, this report reinforces our essential message, which is that individuals, businesses, wind farm developers and other purchasers of wind turbines have a new alternative that is not only efficient enough to make economic sense but is also whisper-quiet, less susceptible to wear and fatigue and safer than many turbines currently in use.”<\/strong><\/em><\/p>\n <\/p>\n If you do a search for wind turbines that beat the Betz limit, the WindTamer Turbine tops the list, and does so with some nice videos.\u00a0 (There seems to be an inverse correlation between video production and idea quality\u2026)\u00a0 As these videos claim to beat the Betz limit, the theoretical maximum efficiency for a wind turbine which most informed people believe is an absolute limit, the WindTamer Turbine warrants some discussion.<\/p>\n Taking a look at the\u00a0youtube video<\/a>\u00a0purporting to explain how the turbine beats the limit.\u00a0 What we see is a high-solidity (lots of blades) turbine inside a duct with a large diffuser extending behind it.\u00a0 The video explains that the diffuser creates a vacuum behind the turbine which increases the air flow through the rotor, boosting the power output.\u00a0 Fair enough.\u00a0 I wouldn\u2019t say \u201cvacuum\u201d, but that all makes sense.<\/p>\n But then the video claims this arrangement produces double the aerodynamic efficiency of conventional turbines and beats the Betz limit.\u00a0<\/strong>\u00a0I don\u2019t believe it.<\/p>\n If you\u2019re not familiar with the Betz limit, here\u2019s the gist of it (WindTamer Corp. might want to pay attention too).\u00a0 Picture a hula-hoop held in the air with wind blowing through it.\u00a0 There\u2019s a certain amount of kinetic power in the wind passing through the hoop.\u00a0 If we put a wind turbine in the hoop, the wind turbine can capture\u00a0some<\/em>\u00a0of the kinetic power passing through the hoop by slowing the wind down.\u00a0 The wind turbine can never take\u00a0all<\/em>\u00a0the power flowing through the hoop because that would entail stopping the wind entirely, in which case there would be no wind to spin the turbine.\u00a0 Aerodynamic efficiency refers to how much of the power passing through the hoop the wind turbine captures.\u00a0 We know that to take all of it (100% efficiency) is impossible.\u00a0 So how much\u00a0is<\/em>\u00a0possible?\u00a0 The backing math can readily be found on the web, such as\u00a0here<\/a>, but the answer is 16\/27 or ~59%.\u00a0 This theoretical maximum is called the Betz limit.<\/p>\n Calculating a turbine\u2019s actual efficiency is easy enough.\u00a0 You simply measure the power produced by the turbine, and divide it by the power of the air that would flow through the hoop if the turbine wasn\u2019t there.\u00a0 As you\u2019ve probably already figured out, this only makes sense if the hoop is the same size as the turbine.\u00a0\u00a0If the hoop doesn\u2019t perfectly surround all the wind that the turbine is slowing down, then the number is meaningless<\/strong>.\u00a0 You can pick any hoop size you want, and get any number you want, but it won\u2019t be a measure of aerodynamic efficiency!<\/p>\n This is the error (I\u2019m not sure that it\u2019s a mistake) that WindTamer conveniently makes.\u00a0 The figurative hoop in their calculations is only the size of their turbine\u2019s rotor, rather than the size of the huge diffuser on the back of the turbine that is providing part of the power.\u00a0\u00a0If WindTamer balanced their books properly by accounting for the full area of their turbine in their efficiency calculations, we would see that their efficiency is in fact quite modest, and significantly less than the Betz limit.<\/strong><\/p>\n For a more detailed critique of the WindTamer efficiency claims, have a look at\u00a0Paul Gipe\u2019s writeup<\/a>.\u00a0 This sort of convenient flaw is common of a lot of unconventional wind turbine developers, unfortunately. As far as I\u2019m concerned, anyone proclaiming to have beaten the Betz limit is either being deliberately dishonest or lacks a solid understanding of what aerodynamic efficiency means.<\/p>\n Despite the shiny prototypes and the still-popular youtube videos, it seems that WindTamer has for the most part disappeared into the woodwork, as most sketchy power device developers eventually do.\u00a0 There\u2019s no WindTamer Corp website to be found.\u00a0 But it seems the technology has been licensed or sold to\u00a0Arista Power<\/a>, who\u2019s website is advertising the turbines using the same false performance claims as found in the videos.[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column][vc_empty_space][vc_single_image image=”608″ img_size=”full” alignment=”center”][\/vc_column][\/vc_row][vc_row][vc_column][vc_column_text]<\/p>\n [\/vc_column_text][\/vc_column][\/vc_row]<\/p>\n","protected":false},"excerpt":{"rendered":" [vc_row][vc_column][vc_column_text] Rochester, NY – December 2, 2009 – WindTamer Corporation (OTC.BB.WNDT-News) today released the results of a performance report from Professor Kenneth Visser of the Department of Mechanical and Aeronautical Engineering at Clarkson University in Potsdam, New York. The report is based on an analysis of field testing in the Geneseo, New York area and […]<\/p>\n","protected":false},"author":1,"featured_media":651,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[171],"tags":[38,40],"class_list":["post-625","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-aviation","tag-movies","tag-trailer"],"_links":{"self":[{"href":"https:\/\/psi-gamma.com\/technology\/wp-json\/wp\/v2\/posts\/625","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/psi-gamma.com\/technology\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/psi-gamma.com\/technology\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/psi-gamma.com\/technology\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/psi-gamma.com\/technology\/wp-json\/wp\/v2\/comments?post=625"}],"version-history":[{"count":5,"href":"https:\/\/psi-gamma.com\/technology\/wp-json\/wp\/v2\/posts\/625\/revisions"}],"predecessor-version":[{"id":1104,"href":"https:\/\/psi-gamma.com\/technology\/wp-json\/wp\/v2\/posts\/625\/revisions\/1104"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/psi-gamma.com\/technology\/wp-json\/wp\/v2\/media\/651"}],"wp:attachment":[{"href":"https:\/\/psi-gamma.com\/technology\/wp-json\/wp\/v2\/media?parent=625"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/psi-gamma.com\/technology\/wp-json\/wp\/v2\/categories?post=625"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/psi-gamma.com\/technology\/wp-json\/wp\/v2\/tags?post=625"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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\nGerald E. Brock, WindTamer’s founder, Chairman, Chief Executive Officer and Inventor of the patented WindTamer technology, said, “We are gratified but not at all surprised by the results of the Clarkson University study. We have known for some time, based on our own testing, that WindTamer will outperform its competition by a wide margin. We have also known that\u00a0WindTamer can produce energy well above the Betz Limit, which has always been viewed as the theoretical limit of the percentage of power that can be extracted from wind moving through a turbine. It should also be noted that the hubs of the WindTamer units that produced these results were only 13 and 24 feet off the ground, which makes WindTamer an extremely attractive alternative to the huge wind towers that are seemingly unwelcome in some communities. The fact that a prestigious research institution such as Clarkson University and a widely recognized, highly respected researcher such as Dr. Ken Visser have now verified our findings is an important seal of approval.”<\/strong><\/em><\/p>\n