The Forum > General Discussion > What price wind power.
What price wind power.
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Posted by Hasbeen, Saturday, 8 November 2008 11:52:39 PM
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It's difficult to explain without having seen the article, but the claim of the grid interactive wind turbine having in fact consumed more power than it delivered over the trial period seems, on the face of it, not what should be expected.
I understand that solid-state inverters are around 98% efficient in converting, let's say, 12V DC to 240V AC. Strict conversion losses are thus minimal. Usually however, such turbines first deliver said 12V DC power into a battery bank for storage, and there are losses entailed in charging, and then discharging, such a battery bank before the simple conversion losses are encountered. There is a difference between simply converting battery stored 12V DC to 240V AC for your own exclusive use, and that of maintaining a grid-interactive supplementation of supply. It appears that either through the genuine limitations of physics, or because the grid-interactivity circuitry has been deliberately designed to consume more power than is really needed to maintain the stand-by capability, that it will be the stand-by capability as an overhead that is negating the value of the system as a nett contributor. Perhaps the key to understanding this outcome lies in recognising that grid power suppliers, especially 'privatised' ones, see distributed generation at the domestic level as a threat to their business model, despite its being encouraged by government policy in the UK. Perhaps the UK test site did not experience, or was deliberately chosen because of the absence of, very good wind conditions. Your experience with a wind turbine in 25 Knot winds on your yacht not maintaing charge in your batteries makes me wonder whether the turbine output was adequately matched to your power demand after losses, or whether there was an automatic dumping of generation in what was regarded as excessive wind speed. Utilities, and behind them, their tame bought 'sponsor' governments, I don't think really want to see truly stand-alone energy independence at the domestic level. You're helping sustain my grid-connected Wind Garden of the Dispossessed, Hasbeen! Posted by Forrest Gumpp, Sunday, 9 November 2008 2:46:11 PM
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Dear Hasbeen.....
trust me.. as one who can design those things.. you had a technical problem. The efficiency these days of power electronics can approach 90% and more.. there is no reason for your wind genny to be so pathetic. "Keep the faith" :) go alternative! Wind generation should always be seen as a supplement not a single source. Solar is also needed. Posted by Polycarp, Sunday, 9 November 2008 5:18:08 PM
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Polycarp, when I set that yacht up, for extended use in the trade wind belt, I was supplying raw materials to a number of industries. One of these was the electronics industry.
Now I hate noise, & I resented having to run the engine to have some light at night. I asked a couple of the best in the electronics business, at the time, [early 70s] to recommend the best wind generator, & the most suitable solar cells, for me to fit. They went further than that, they selected the gear, installed it, & built switching gear, to connect the thing with the most output to my 350 AH battery system automatically, during the day. When this system could only sypply 2 hours of light a night, with the yacht in Sydney, they modified it, to include my engine, & finally a nice quiet little gen set, supplyed by Mr Honda. They assured me the free stuff would kick in, to great effect, once in the tropics. It never did. It was Mr Honda, that kept me reading for many years. I used to muck around, seperating the battery banks, & hooking the solar to one, & the wind to another, to try to get some return for my buck, then reconnecting them at night. I used to think of it as my joke on myself. Recently I did get a solar unit, which kept my occasional use tractor battery topped up. Well it did for the 3 years it lasted, about as long as a similar priced new battery would have lasted. From the Which artical, it does sound as if the proof of this stuff is still in the pudding. Posted by Hasbeen, Sunday, 9 November 2008 10:25:33 PM
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The more I think about it, Hasbeen, the more it seems those who recommended your wind generator set up did not match it's anticipated output to your intended usage.
Did they not recommend a tow generator instead? Granted a tow generator acts to an extent like a sea anchor when in use, but the unit itself can be made more compact for stowage due to the greater density of water enabling the production of far greater power for any given blade area than can be obtained from wind. That way you could have linked the far greater windpower of the sails to your generation requirements. I am assuming the yacht sailed satisfactorily normally, driven by the trade winds. As to what boat speed penalty you would have had to pay when using the tow generator, I am uncertain. I also have no idea of how much they typically cost. In the more general context of attaining energy self-sufficiency, the major obstacles are those of the expense of storing electricity as electricity, and the relative intermittency of most primary sources of energy. I believe one of the most attainable solutions is that of using a stored energy primary source for electricity self-sufficiency: wood. Wood can be pyrolysed using fairly unsophisticated solar thermal technology, and the resultant charcoal and wood gas stored, again using similarly unsophisticated technology. The wood gas can then be used in conventional IC engines to generate electricity as and when, and to the extent, required. Don't like the noise of a motor driven generator? Use a simple combination solar thermal, wood, charcoal, or wood gas fuelled thermo-electric generator in combination with a battery bank and inverters (if needed). No noise. No moving parts. It is interesting to note that the one form of renewable energy that attracts little or no government support for its adoption in stand-alone power installations is, yes, you guessed it, Australian native hardwood fuel. Too low tech. Too attainable for Joe Blow. Anybody can pick up sticks, but such activity tends not to be viable for large corporations. Posted by Forrest Gumpp, Monday, 10 November 2008 11:06:13 AM
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Hasbeen you have some good responses from the technically minded so far.
Extending this idea a bit (apologies). Alternative energy like wind and solar will have to play a big part in our future but the ABC's Landline program on Sunday made me see that the issue is not not as clear cut as might appear. http://www.abc.net.au/landline/content/2008/s2413427.htm I am all for wind power in theory, but the issues covered by Landline included visual and noise pollution. Do we want to see huge industrial wind machines along all major parts of our coastline and rural ridges? I would like to see some wind farms in the more isolated areas but am unsure how I feel about them becoming a dominant feature of our wonderful Australian landscape. The earlier concerns about birdlife were apparently unfounded as shown by a study at the Crookwell site when after six months not one bird was found to have been affected. Siting the poles out of bird migratory zones is one way to avoid this in any case. This issue is dividing communities and families if the media's take on this is correct. What do others think? Posted by pelican, Monday, 10 November 2008 11:21:24 AM
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Which installed a domestic wind turbine on a house, in late 2007. they then monitored the performance of the thing, from December 2007 to June 2008.
What they found was that the thing worse than useless.
These things require an inbuilt inverter to convert the energy gathered to 240 AC to use in the house, or feed into the mains. The invertor is powered 24/7, from the mains.
Would you believe, the inverter used more power, in the 6 month period, than the turbine generated.
I still own one of these useless bits of junk, but I may have trouble finding it. I float tested it, about 20 miles north of Willis Is, [mid Coral Sea], when I found it would not put anything into my yachts batteries, even in the 25Knot trades, blowing at the time.
I did think they may have improved in the 32 years since then, but apparently not.