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Forum Index : Windmills : Is my wind site worth it ??
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| cyclone Newbie  Joined: 25/08/2006 Location: AustraliaPosts: 1 |
Hello, My first post. Here's some data at 10 metres, http://www.gorgecreekorchards.com.au/energy.gif They are 10 min averages. Will i be wasting my time in a wind turbine ? thanks Live Weather Data & Lightning Tracker at http://www.gorgecreekorchards.com.au |
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makourain Senior Member  Joined: 19/04/2006 Location: Posts: 111 |
its never a waste of time if u have fun ;) |
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| RossW Guru  Joined: 25/02/2006 Location: AustraliaPosts: 495 |
I guess it depends on your definition! Hard to corelate your figures, "hours at 12KMH" is very bad wording - but I guess they mean each band from mid-way between one speed and the next, so "at 12KMH" probably means from 10 to 14KMH. Here are the last few months of mine, sampled much closer to the ground (4.5 metres) but then, I am 150 metres above the town on a hill! Mine are sampled every 5 seconds, so somewhat more datapoints then you have. I've only broken it down into 5KMH bands because its easier. Mid-March to about an hour ago: Wind Velocity histogram: 00-05kmh 2230.6 hrs 05-10kmh 1086.1 hrs 10-15kmh 507.5 hrs 15-20kmh 165.7 hrs 20-25kmh 58.2 hrs 25-30kmh 11.1 hrs 30-35kmh 1.9 hrs 35-40kmh 0.3 hrs And here's the monthly breakdown: Wind Velocity histogram for Apr 00-05kmh 337.8 hrs 05-10kmh 160.2 hrs 10-15kmh 134.1 hrs 15-20kmh 60.0 hrs 20-25kmh 23.7 hrs 25-30kmh 3.9 hrs 30-35kmh 0.5 hrs 35-40kmh 0.1 hrs Wind Velocity histogram for May 00-05kmh 435.9 hrs 05-10kmh 195.9 hrs 10-15kmh 71.1 hrs 15-20kmh 26.6 hrs 20-25kmh 10.8 hrs 25-30kmh 2.4 hrs 30-35kmh 0.5 hrs 35-40kmh 0.1 hrs Wind Velocity histogram for Jun 00-05kmh 487.4 hrs 05-10kmh 181.9 hrs 10-15kmh 39.2 hrs 15-20kmh 8.1 hrs 20-25kmh 2.2 hrs 25-30kmh 0.4 hrs Wind Velocity histogram for Jul 00-05kmh 339.0 hrs 05-10kmh 217.9 hrs 10-15kmh 123.0 hrs 15-20kmh 34.9 hrs 20-25kmh 8.9 hrs 25-30kmh 1.4 hrs 30-35kmh 0.1 hrs Wind Velocity histogram for Aug 00-05kmh 372.9 hrs 05-10kmh 148.4 hrs 10-15kmh 51.2 hrs 15-20kmh 15.2 hrs 20-25kmh 5.2 hrs 25-30kmh 1.0 hrs 30-35kmh 0.2 hrs Over the last few months, the windgen has certainly been helpful in reducing generator run-times, but damn, I'm glad it's not my primary power source. There would have been lots of candle-lit dinners! I have a 1KW turbine (and yes, I've seen more than 1KW out of it, so it's not an empty claim!). Fortunately, I didn't pay much for it ($1500) but it isn't likely to pay for itself any time soon. (Still, if the price of LPG keeps going up it will!). It's nice to know that I've saved SOME greenhouse emissions between the PV cells and the wind turbine, but from the wind I see you have there, unless your power demands are VERY modest, don't bother unless its mainly for personal satisfaction. For what its worth, my generator kicked in yesterday about 16:00, because the batteries reached the 30% discharge point. Today which was substantially the same in terms of sun and power demand, the generator didn't kick in until about 10 minutes ago (18:55). The only difference was today we had a reasonable breeze! 
And of course, the all-important wind-rose:  |
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| petanque don Senior Member Joined: 02/08/2006 Location: AustraliaPosts: 212 |
Looking at the statistics the majority of the time there is less than 12 Km/hr breeze Assuming you are connected to the grid economically the cost benefit analysis is unlikely to be favourable. If you are looking at green energy if you would be better to investigate something like a suncube http://www.greenandgoldenergy.com.au/ would be up to you. However if you think you would enjoy the tinkering or engineering challenge of making a windmill clearly you can’t put a price on this enjoyment. |
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| RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495 |
Have you (or anyone else here) tried to buy one of these? I've been chasing them for a year, waving money at them and have come to the conclusion it's some whacko crackpot who doesn't really have anything to sell and is just in it to extract some sort of grant from the government. Never returns calls, never responds to e-mail, is full of hot-air on the phone but cannot or willnot commit to supply. Each time it's been "in a month"... but after year (I spoke to him again about 4 weeks ago) it's STILL another 3-4 months away (after a year of being a month away). Very disappointing. |
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| petanque don Senior Member Joined: 02/08/2006 Location: AustraliaPosts: 212 |
I have met Greg he seems a little eccentric. While he seems a competent engineer I am uncertain about his business skills. Living in Adelaide I should drive past his factory some time and check it out. Greg seems to be overly optimistic at the speed that government agencies work at. I would be surprised if he has approval before early 2007 I have examined the prototype “sunball” and it looked like a sensible workable thing. I would think that when they are available the initial rush will be huge. I have no idea what levels of production are intended. I am supposedly on the list to purchase a system. Unfortunately a great product is only part of having a great business |
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Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1343 |
Well is that sun rose your talking about is the one the solar shop is trying to flog and the same one that was posted on the fieldlines board ?. If so beware it looks like another pure aussie scam and as far as the solarshop goes if you want to pay 10's of thousands of dollars for an RE setup that never works properly use them. Why do I say this I got suckered by them to the tune of $25,000. I reckon I've had them up here about 10 times and they still didn't get the inverter set right even I gave them all the data from selectronic which they didn't have. Now they made up a special warranty for me saying if any of my re gear went bung I was on my own and they demand $300 up front to come up and fix there stuffups. When I say the re isn't working properly I paid over $4,000 for a datalogging inverter that can't tell whether amps are coming in or going out, and when I investigated why I had a 11 amp phantom load all the time I found a couple of wires were in the wrong spot according to the selectronic data. Well enough of me ranting but anyone in Adelaide if your going RE stay well clear of the solarshop and their sun rose scams. |
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| RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495 |
Oops, why didn't someone say it didn't show! |
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| dwyer Guru Joined: 19/09/2005 Location: AustraliaPosts: 574 |
Hi l just look at this feller ideas is full of scam and didnt tell how this work and one of the photo showing on the roof doesnt mean anything however in USA have spend millions of $$$$ trying improve solar power for their spaceship or satellite so why havent taken up his idea now ?? Can you explain it and Ross if you were me l would not waste my money just right now 
dwyer the bush man |
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| RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495 |
Dwyer - the principle seems sound. Look up the full details on the fore-runner, the "Solar Sphere". It was something akin to the "Steel Drums" from Trinidad - vis, a half-spherical shell with (from memory) 7 small PV cells. The flat "top" of the pan had a series of fresnel lenses which focused the light from the whole segment onto the small PV cell. Again, from memory, it was "50 suns" worth of light intensity on the chip. The pan then tipped ("rolled") while the whole assembly was able to turn on its central axix, thus making a 2-axis tracking head. More than just a luxury, this was essential to ensure the light remained focused on the cells. The back of the pan was made such that it was able to disssipate the (quite intense) heat, since it was always facing away from the sun, and a MPPT (Maximum Power Point Tracking) converter made whatever your required output voltage was set to from whatever was available from the cells. All in all, its a sound idea. Obviously, the construction of this simply didn't scale for "mass production". I expect the fresnel lenses were quite expensive, and spinning the hemispherical head was probably horribly expensive too, so it looks like they've taken the key concepts and just made little square boxes that stack together and renamed it the cube. Again, I'm sure it'll work, and work well. Just that despite being promised one of the early ones, and waving money at the guy, he's simply got really, really bad interpersonal skills! *** LATER *** Ahh, I was completely off the mark here! It's a "SunBall". I can't see the smaller (prototype) pics and descriptions I saw a year ago, but the much larger (1.2 metre dia) unit has 25 cells, not 7. (Perhaps the original, smaller unit had 7) 
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| AllanS Regular Member  Joined: 05/06/2006 Location: Posts: 67 |
Those fresnel lenses are quite cheap. I saw them on ebay for about $10/sqft. The triple-junction solar cells are the killer, costing $100000/m2. Ouch! They're close to 40% efficient at high light intensity, which is stunning, given direct solar illumination is about a kilowatt/m2. The cells need the full spectrum to work, but the lens tends to disperse the colours. A kaliedescope-thingy just above the cell fixes this but also absorbs some of the light. You need a really good heat-sink. Efficiency drops 4% (from memory) for every 10 degree rise in temperature. Also, you need very good tracking, down to fractions of a degree. There's a fancy sort of mirror out there that uses 'non-imaging optics'. These funnel light rather than focus it, producing intensities of up to 80000 suns, believe it or not. They work with very rough tracking, and they work with diffuse light. A US company is making inflatable versions. I'll see if I can find the link. |
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| RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495 |
Much cheaper than I expected (although perhaps the cost was in cutting them to the strange shapes? I base the "expensive" comment on his obvious dismay at cracking one) Yes, which is why as long as the fresnel lenses are significantly cheaper per square metre, this has to be a good option :) Yes, and in his early descriptions he pointed out that the cells are bonded on a copper slab which is in turn bonded to the quite large aluminium back of the assembly. Given that it HAS to be in shade when the front gets hot, it makes an excellent heatsink, with the PV cells only getting a few degrees above ambient. 80,000 suns?! Are you saying a 1 metre square collector could funnel that into a kilowatt point-source 3.5mm x 3.5mm ?? Damn, that's gunna create some heat! Thermal resistance of copper in 1 metre/second airflow (ie, light breeze) is about 0.6 degC/W, so we'd expect close to 600 degrees C! |
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| petanque don Senior Member Joined: 02/08/2006 Location: AustraliaPosts: 212 |
The Suncube works at about 500 suns. The lens for the large round one cracked when a visitor at a trade show decided they would examine the Sunball without invitation. Many people would get grumpy if a stranger came and broke your stuff. While it is interesting to hear about the solar shop and if you purchase an item you do have recourse if it is not fit for purpose. Realistically this is from a different organisation and their customer relations slant may be different. Currently it is unproven. Personally while I am very interested I won’t be an early adopter of this technology. |
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