Evolution in nature and technology play out much the same way: After periods of relative calm, something comes along to shake things up so that the biology or industry segment gets a radical shift. Then things calm down for a while. Anthropologists use something close to an “S” curve to show the activity versus time. If you lived through the computer revolution you saw an example of a disruptive invention at work. For instance recall how the early computer-assisted drawing software quickly pushed drawing boards aside. Wide format printers, 20 in. and more, jostled for work beside the new office computers. The following decade saw the PC rise to push out the Unix-based workstations, and then become commodity products. Competition in computers has since calmed down, and the battle – if you can call it that – has moved to cell phones.
Developments in wind technology hint to the end of a calm period. For instance, the conventional design for the last decade has been a horizontal axis with a three-blade rotor on at least a 60-m tower. Inside the nacelle, a gearbox speeds main-shaft rotation about 100 fold to drive an induction generator. You now see design ideas shifting away from problematic gearboxes to direct drive units with minor weight saving. What’s more, profits from conventional technology are skimpy and only show positive because of the production tax credit, a gift of encouragement from the government to wind farm owners.
The setting is just about right for some out-of-the-box thinking to come along and reshape the face of the wind industry. After the recent show in Dallas, you might predict the death of the gearbox. That would be disruptive for companies working to make gearboxes more reliable. Superconducting generators, smaller and lighter than conventional generators and in a variety of sizes, might let owners refit gear-driven fleets as direct-drive units. Or possibly someone is on the verge of finding a way to make inexpensive permanent magnets, which could be disruptive for manufacturers of induction generators.
Turbines that need no towers could be disruptive. Magenn’s helium-filled rotor is one such design. Its developer intends for it to float more than 1,000 ft up where winds are strong and steady.
Or what about a wind-powered generator without the conventional generator or rotor? One with no rotating parts at all? Accio Energy, Ann Arbor, Mich., claims to be building such a device. The company says wind blowing across its engineered tubing somehow separates electrical charges to create electricity, and generate about 1 kW from 640 in. of tube. The company says it’s well within the manufacturing capability of many idle auto plants and can be manufactured in a variety of shapes for about a penny per inch. A company spokesman says to watch for a demo next year, a pilot project the year after, and commercial sales after that.
Like I said, I don’t know where the next big change is coming from, but it’s coming.
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Bill O'Keeffe says
I was very interested in your WindPower Engineering articles, especially the “Will a disruptive idea upset wind’s status quo?” article and the one deaaling with insurance. I have designed, and applied for a patent that will generate electricity for hybrid cards, on the top of the hill, on top of high buildings in the down town, and also on ships/boats. I think this will be the disruptive idea to upset wind’s status. It has many features available in the common Wind Turbines scattered across the horizon. Its electrical power generation matches the wind turbine generators for all but the “super blade” turbines.
I have prepared a CD/DVD which describes my invention. For the price of your comments I would be pleased to send you a copy. Your comments will not be used in the promotion of my invention.
George Fleming says
Since I am working on gearbox improvements, I believe that the trend to direct drive is a mistake which will become evident before long. With a geared drive train, the power electronics in variable speed turbines can be eliminated, as shown by the DeWind 8.2 and other turbines. This technology uses a conventional synchronous generator which does not require permanent magnets. It produces pure sine wave power. It does not use nearly as much copper as direct drive. Geared drive trains have other advantages that are not yet apparent to the industry. This is not to say that current wind turbine gearbox designs will survive.