While it is uncomfortable to admit, all of the great science and technology that can go into a better wind turbine means nothing if the wind industry lacks any kind of profitability. There is simply not any significant R&D funding from governments that can compare to the $3 trillion that the U.S. has spent on nuclear weaponry and associated nuclear reactors to make said weaponry mass produce-able, or the hundreds of billions spent by the U.S. government and quasi-governmental institutions like EPRI, The Edison Institute, the API (American Petroleum Institute), as well as many major corporations (oil and gas companies, electric utilities, coal industry, nuclear reactor construction and equipment companies, etc). Sometimes it is hard to figure out where governments (federal and state) end and companies, non-profits,"for-profits" begin. And there is also a lot of evidence that in the wind industry, most of the developments have come from private industry and not from government R&D, though governmental R&D would certainly be helpful.
But, getting private R&D money is only likely if this industry is going to be profitable, and consistently so. So, please check out the following legislation from Representative Jay Inslee of Washington State:
While this one may be a tough sell, there is always the state approach, too. Both Michigan and Minnesota have Feed-In Laws working their way through the legislatures, and it could always be tried in NY State, too.
Anyway, with a market somewhat insulated from the wild gyrations of petroleum and natural gas and now even coal
(http://www.eia.doe.gov/cneaf/coal/page/coalnews/coalmar.html#weekly), turbine manufacturers and their component suppliers can go about the business of making better and more cost effective products, especially with regards to a long term view. Wind turbines and many of the components in them are a capital intensive business, with a several month to a few years time frame, and energy price predictability will result in long term gains for all, better products and of course, more jobs. And "more jobs" is a good thing, right?
In this month's North American Wind News, there was a brief discussion of gear versus less gear versus gearless wind turbines. So, here is a bit of an explanation. Most wind turbines made, and especially those sold in the U.S., are the geared types, where a 3 stage gear system ups the rotor speed (which is often variable, depending on the wind speed) of 5 to 25 rpm to a maximum of near 1800 rpm. Some examples are the wind turbines made by Vestas and GE. The world's biggest producer of gearless turbines is Enercon (http://www.enercon.de/en/_home.htm ---> Technology), and an example of the hybrid (one stage) system can be seen with the Multibrid (now owned by the French government owned nuclear company, Areva: http://www.multibrid.com/index.php?id=10&L=1).
The use of a speed-up gear system does introduce a loss of up to 5% - just another consequence of thermodynamics, where any conversion of energy into another form (low speed high torque into higher speed, for example) comes at a cost, which is usually manifested as waste heat. These losses are still pretty small, but they do add up - for example, this could be 125 kw for a 2.5 MW machine. However, since the 2.5 MW machine is on average only going to make less than 1 MW, this would only be a 50 kw loss. But for 1000 of these, that is 50 MW, and for 100,000, that is 5 GW, or about 1% of the U.S. consumption. The reason that companies employ the gear speed increaser is due to the way the generator is made. Most wind turbine generators are just a squirrel cage big electric motor, wired and configured to make electricity instead of consuming it. However, these generators can be turned into motors by adjusting the "slip" between the magnetic fields of the rotor (moving part) and stator (stationary part) of the generator/motor - see http://en.wikipedia.org/wiki/Doubly-fed_electric_machine.
A generator in a 1.5 MW GE machine would be the same as 1934 horsepower motor. If it operates at 1800 rpm (= 30 times per second), and if it has 6 poles (magnets), it would change magnetic alignment (north to south) 180 times per second. For 3 phases, each phase would change 60 times per second, alias 60 cycle (= 60 Hz), which is the line frequency that we use in our daily lives. Such motors and generators are commonly made, or existing ones can be modified to suit this arrangement. These motors are also reasonably compact, and "only" a few feet in diameter. For example, this site can give you dimensions on a 1500 hp motor (1200 kw) - it is 3 feet in diameter (0.85 meter) and about 8 feet long (2.4 meters), weighs about 6 tons and costs about $172,000. Wind turbine generators also have some extra features to them, like associated heat exchangers to keep them cool - see http://www.tecowestinghouse.com/teco/products2.aspx?partID=AEJHTK-04-15000A2&partIDExt=blk&command=detail or snoop around that site.....
However, if this generator was replaced by one with more poles, a slower rotational speed could produce the same output frequency. For example, using a generator with 108 poles, the rotor would only need to spin at 100 rpm to make a 60 Hz signal. For a variety of reasons, the diameter of the rotor would need to be bigger, as would the corresponding diameter of the stator. Which is why the rotor/stator of a big Enercon can be more than 10 meters (about 33 feet), while a conventional 1.5 MW generator is "only" about 6 feet in diameter. On the Enercon E-126 turbine, the world's biggest at 6 MW, the bulk of the nacelle mass of nearly 500 tons is take up by the generator. These multipole generators tend to be more massive and certainly have larger diameters, which makes them more costly. However, there is less friction loss in the gearbox when there is no gearbox, and less wear and tear (1800 rpm versus 10 to 100 rpm) on seals and bearings, and less things to go wrong. the gearboxes for most turbines are also big and heavy, and also complicated, with oil pumps, filters and monitors needed, plus cooling systems, as all that friction causes heat build-up, which has to be dissipated. And there is the noise aspect - things are noisier when moving fast than when moving slow.
The losses in the gearbox also occur in another way - mechanical problems. And this causes money problems - repairs might even include renting a crane at $100,000 per month (and for any part of that month), for starts. Gearboxes tend to be a major part of the mechanical problems encountered by wind turbine owners. For example, if turbines are "down" 5% of the time, a major reason will be gearbox maintenance and/or repairs. Take away the gearbox and associated high rotation speeds put onto the generator, and less maintenance is required. Recently Siemens announced that it will be trying out a gearless design on its 2.3 MW turbines (two units in Denmark). As wind turbine size goes up, the benefits of less losses and a smaller gearbox/lower speed generator tend to add up. However, there are also some intermediate sized producers, notably this one: http://www.awewind.com/, and even a small one (http://www.distributed-energy.com/).
So, how does this relate to a Feed-In Law? The competition in the wind industry is intense, and this industry is growing at an impressive rate - perhaps by more than 35% for 2008 on a worldwide basis. Some companies, notably Enercon, will not even sell into the U.S. market, due to the unreliable electricity pricing that is the norm. Many others have to be closely attuned to next quarter's and next year's profits, and any long term advantages are not applicable. This is especially true for many developers, who are trying to keep the prices of wind turbines as low as possible, even though they have increased in the last two years. By allowing developers and the manufacturers who supply them a predictable cash flow for a 20 year time frame, the competitive aspects of the business can change from the present intensely short term focus to one more longer range, and one where items such as maintenance costs gain grater importance. And also to one where high initial capital investment is favored to a greater extent, since longer term financing will be available at lower rates due to the lower risk of such loans. Feed-In Laws will change the rapid pace of the development (make it faster), and also allow for greater R&D into higher yielding wind turbines, and not necessarily into lower initial cost machines, but lower long term overall systems.
Top News of the Week, 28 Nov – 04 Dec 2016
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