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Forum Index : Windmills : Newbie Grid connect windmill idea
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Greenthumbs Regular Member  Joined: 05/12/2008 Location: AustraliaPosts: 40 |
Hi everyone, I have been looking at this forum for a while now and have decided to get in on the action. There are so many ideas, info and projects it is all a blur :) I live in the Adelaide hills and in november 2007 had a 1.8Kw solar grid connect system installed on the house. Its great but half the year we live in the clouds where the wind blows but the sun don't shine:( I have been collecting F&P motors for a while and have come across 3 so far. We would like to harness the wind power. We have been logging the wind data for a while now but just resently seen a post on the forum saying my data will be no good because I am only logging every 15 minutes. However I am keen to try it out anyway because I reckon there will be pleanty of wind. My plans are to put up two 48volt dual stator mills In parallel. I was going to rectify them and then parallel them and then use a Latronics TC48 windmill controller to control there speed. I was then going to connect them to the grid using a Latronics PVE1200 inverter. Because I am new to all this I was wondering if anyone would have any words of wisdom for me. Would this Idea work or is there a problem with connecting mills togeather? The reason I was going with 2 in parallel was because I want to get power in the lower winds. If I was to uses a 1Kw mill I figured that they have a higher cut in speed & they cost lots more. I have been looking at Trevs Fibreglass and foundry white pointer mills and thought that two of these might do the trick. I would love to make the mills but time restrants always get in the way:( The Turbine controller can handle up to 25amps 75Volts before slowing things down. |
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GWatPE Senior Member  Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
Hi greenthumbs, You may consider seeing my setup. I am not too far away, on the south coast. You may have seen my windmills if you have driven down this way. I have a similar setup to what you are considering. Direct feeding of mill energy back to the grid with a PVE1200 does work well, if overvoltage protection is adequate. Phillm has a similar setup, as well as Bolty. I am sure there are others as well. Grid connection with windmills is still a grey area. I use a battery, and use as much power as possible with a stand alone inverter. Half my house runs OFF grid. My solar is grid connected. I have attempted to keep the wind energy below the base load of my house, to avoid issues with grid connection of the windmills. I buy and sell power to maintain my backup battery. We experience grid outages when power is switched between VICpower and SApower. During these times, it is imperative that overvoltage systems operate when the inverters are anti-islanding. Gordon. become more energy aware |
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Bolty Regular Member Joined: 03/04/2008 Location: AustraliaPosts: 81 |
Hi Greenthumbs. I have the Latronics TC48 controller and the PVE1200 inverter connected to a 1Kw Chinese turbine rated at 48 volts. Even so, the low end performance has been poor. Gordons voltage doubler idea worked a treat for me in improving the low end. Even though I blew up some Mosfets in the controller due to a design oversight, it is now working really well. See my latest listing here: http://www.thebackshed.com/Windmill/FORUM1/forum_posts.a sp?TID=1138&PN=1&TPN=17 I have to say that I have been pleased with the Latronics equipment. Also I have been delighted with their after sales service. I had an intermittent fault in my PVE1200 that required me to return it to the Latronics factory. They extensively tested it over 2 weeks and when they could not replicate the fault, they decided to send me a new replacement inverter to avoid any more problems. You can't get much better than that! As for your idea of putting 2 F&P in parallel, I am no authority to answer that. Gordon has heaps of experience with these and would be best to advise you! Thinking out of the square, I am wondering if you might be better putting the 2 turbines in series at the DC level after the rectification. This should give better low end performance, but I don't know enough about the F&P voltage characteristics, to know what would happen at the high power end. Then again, the voltage doubler circuits handle the low end performance really well. Good luck and keep on learning. This is a fascinating field that I find massively engaging! Even with my 1 Kw turbine, it is going to take a very long time to become cost neutral....if that is your intention through wind turbines, it may be a good idea to not start. However if you want to do your bit in learning, etc, then go for it! All the best! Bolty |
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| Greenthumbs Regular Member Joined: 05/12/2008 Location: AustraliaPosts: 40 |
Thanks Gordon & Bolty for your replys 
Yes Gordon the over voltage thing when the mains goes off did worry me but I have emailed Lantronics and they stay that the TC48 Turbine controller will just sy\top the mills with its (auto electronic braking). Guess I will have to see if the smoke escapes when it happens:( I am going to get a electricion to fit the inverter so I am legal, so as long as the turbine controller does its thing all should be good. We turn the meter backwards when we are not home with the solar array but now thats not good enough for me. I WANT MORE! So putting a turbine in or two, so I can produce power over night is the go :) I wanted to use a PVE2800 and controller and run 2x mills in series at 96v but when I emailed Lantronics with some questions about how their controller operated they said "It is not a good idea to put turbines in series" no explanation given. With that setup there was room to expand. This is why I asked the question about mills in parallel. Question have you guys ever reached 25Amps? Bolty seeing as you are using a TC48 Do you have a furling system on your mill or does the controller just do the job? Thanks heaps for your replays Regards GreenThumbs p.s. Bolty I will look at your latest listing real soon. I am on a 56K link. A bad one at that I keep dropping off da net. GRRR :) |
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| GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
Hi greenthumbs, My power meter was going backwards as well on the solar. The utility soon changed the meter, something to do with GST. You may have to pay for this. All rebated grid feeding setups require separate import/export metering now. Gordon. become more energy aware |
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| Greenthumbs Regular Member Joined: 05/12/2008 Location: AustraliaPosts: 40 |
Yes I have had that done after six months. I guess it is not as exciting this way but it is going backwards electronically sort of. if you calculate... |
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| Bolty Regular Member Joined: 03/04/2008 Location: AustraliaPosts: 81 |
Hello again Green thumbs Sorry I have not answered sooner, but I have been visiting daughters in Melbourne. Just got home to find not much power generated whilst away. I had though that it was windy here at Victor, but apparently NOT, as my wind has only produced 1.5 Kwh in 4 days. In contrast the 1Kw solar has put 22.5 Kwh into the grid. This is apart from what it produced for keeping fridge and 2 freezers going. If it was windy whilst I was away, there could be something wrong with my system, as I left it in a highly temporary state after experimenting with caps and the voltage doubler. Unfortunately, I have no wind records from my weather station, as I turned off the computer whilst away. This is because it has not been sleeping properly, and I did not want to waste all that energy whilst in Melbourne So in summary, if you look at my example above, don’t have too high expectations of the amount of wind energy that you will produce. Your thinking of getting wind energy at night times, reminds me of my motivation 8 months ago in getting wind happening. Now I realize that Gordon’s rule of thumb of 80/20 is pretty right. That is for 80 % of the time, you will get only 20% of the power. In relation to your questions, I do not feel that I have sufficient knowledge to predict what would happen if you did put 2 F&P in series. Because mills (even very close to each other) spin at different speeds, each would generate different voltages. I can’t see why this would be a problem with them in series, as the effective internal resistance of each alternator/ rectifier combination, would be quite low. Therefore each combination should effectively add their voltages together. In parallel, I guess that each machine would contribute its own current, with the total current being the addition of each! No I have never seen 25 amps, as I don’t measure the current from the turbine. I usually measure the mains power produced. I have seen 1250 watts here. At this power, the turbine is producing around 70 volts, so the DC current max from the rectifier would be around 18 amps. This is despite the fact that the turbine is nominally 48 volts. NB my Latronics combination does not generate any grid power until the DC voltage reaches 54 volts. The TC48 does do a really good job now that I have used capacitors, as it brakes more softly. Prior to capacitors, the brake was extremely harsh, and it generated a back EMF of around 105 volts. This was somewhat worrying, as the brake applies at 75 volts, but then the sudden voltage increase must surely have been over-rating the capacitors in the TC48, as these are only 80 volt rated. Also the back EMF on braking was getting perilously close to violently exceeding the maximum voltage ratings of the Mosfets in the controller (100volt rating). Apart from the TC48 brake, my Chinese turbine does furl, although I have only once seen it doing so! Gordon has emphasized to me that it is very good practice to NOT entirely rely on electronic devices to control upper limits with wind turbines. Electronics do fail. With no furling, self destruction of your turbine is simple if your electronics fails!!!!! |
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KarlJ Guru  Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
I also spoke to LA tronics about 2 500W turbines on one controller, in short read the article about the caps and look at the traces from the ocilliscope on a rectified turbines output, its not pretty, hook two up together that are slightly out of phase and whalah -smokin! I also logged at 5min intervals and was shot down by the forum guys, now logging at 30s intervals, what I have learned is that logging in shorter intervals does not make it more windy! I thought my place was windy and it is, but 10m/s which most turbines are rated is WINDY!, my avg windspeed not bad -until you look at how much power a 1kw rated turbine makes in 4.5m/s and its probably only 250w at best making it a hobby. As Bolty has a grid connected system with a 1kw turbine fully installed at $4K or therabouts, he mentioned in another post that it would need to make 5KW/hrs a day for the next 15years to pay off. Thus unfortunately for most of us makes it a hobbby. I too am like you and looking for a cost effective solution to this dilema as there is nothing more rewarding that watching a wind turbine (as opposed to solar cells doing nothing) but in order to make it worthwhile everything has to match perfectly (as far as I can tell) and not cost the earth, which onece you talk grid connected satrts no longer being the case. So far my biggest win was the solar hot water, for $1500 I have not boosted my hot water in almost 2 years, just added an evacuated tube collector to existing (normal) tank. Luck favours the well prepared |
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fillm Guru Joined: 10/02/2007 Location: AustraliaPosts: 730 |
Hi Greenthumbs, I have been meaning to repily to your post for a while , wireless conection troubles , anyway as most have answered your questions , I can only explain my set up , as Bolty has said to most of us it is purely a hobby as unless you have 25klm+ wind blowing constant wind gens will never out do solar. My 1.3Kw grid connect pumps back 8 to 9Kw a day at present but you can't tinker with it and as stated it's pretty boring watching solar panels . But as far as hobbies go, watching all your work come to life and start to produce usefull power even though at the end of the day its probably cost 100 times more than it will generate in a life time is rewarding , some have $10,000 boats sitting in the back yard doing nothing 11 months a year and that list can go on and on. As with series windmills , I thing you have your answer , if you need 2.5 Kw use two Pve 1200 like I have done , One for the 1Kw and the other for my windmills and it keeps the voltage at 48v. All the best with your learning curve ..Phill.. PhillM ...Oz Wind Engineering..Wind Turbine Kits 500W - 5000W ~ F&P Dual Kits ~ GOE222Blades- Voltage Control Parts ------- Tower kits |
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