 Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me. |
Forum Index : Windmills : Old mill tower - new use
| Author | Message | ||||
| MOBI Guru  Joined: 02/12/2012 Location: AustraliaPosts: 819 |
Hi all, I had an old 4 post windmill tower left over so I decided to use it as tower for the 500watt turbine. Problem was to get the turbine to sit on top of the tower but still be easy to lower to the ground for maintenance or in the case of very strong winds (something we are not short of here). I had seen Downwind's design and decided to incorporate the hinged pole and swing-over latch at the top into my setup. Guy wires were a severe inconvenience, hence the mill tower. The cross braces on one side of the tower were removed and re-sited to just past the middle of the tower with the top being completely open. A 75mm galv light guage water pipe was hinged at the bottom just above the lower cross brace (left this one in its normal place). This allows the pole and turbine to be lowered to the ground, ending up about 1 metre from the ground.(a nice height for working on). The pole is winched up and down using a light weight boat winch. At the top is a swing-over latch that combined with the winch, stops the pole from coming down. The bit I like, is the "no guy wires" 
David M. |
||||
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498 |
I like your tower idea however I would be putting some extra bracing from the sides that you removed the bracing from. Those to sides out there can easily flex in towards each other or out making it very susceptible to collapsing under load. There are only 10 types of people in the world: those who understand binary, and those who don't. |
||||
| MOBI Guru Joined: 02/12/2012 Location: AustraliaPosts: 819 |
[quote=madness]I would be putting some extra bracing from the sides that you removed the bracing from.[/quote] If you look closely in the third photo, you should see that the bracing that was on the outsides of the tower has been refitted roughly across the middle of the tower in the same direstion that it was. Also, the bottom bracing which is about a metre up from the ground is stil in its original position. I have been making and installing and using windmill towers for years. You should also notice that the diagonal bracing on the other three sides is still fitted. It has been through some pretty horrendous gales here and hasn't batted an eyelid. The windmill head that used to be on the tower had way more wind loading than this little turbine has. David M. |
||||
fillm Guru Joined: 10/02/2007 Location: AustraliaPosts: 730 |
Hi David, Nice work , good to see. These little 500W mills can fairly churn out the power when set up correctly, and I doubt the tower would bat an eyelid to cyclonic wind. PhillM ...Oz Wind Engineering..Wind Turbine Kits 500W - 5000W ~ F&P Dual Kits ~ GOE222Blades- Voltage Control Parts ------- Tower kits |
||||
| MOBI Guru Joined: 02/12/2012 Location: AustraliaPosts: 819 |
Well, Does anybody want a broken wind genny and a versatile tower to go with it? (see the pics at the top of this post) I have decided to go totally solar/inverter (stand alone, off grid). This is the 4th wind generator or version I have had and the umpteenth breakdown. Now also, I have a very black thumb from trying to separate the stator and rotor to replace a broken axle. (Boy are those magnets powerful!!)The replacement axle pressed in easily on the hydraulic press but did not align properly so the windings rub where they shouldn't. On sunny days, I have never needed the wind genny and mostly on overcast days, there isn't enough wind to charge the batteries. Meanwhile, it was fun playing with the control circuitry etc. My main bank of panels 8 x 80w (4x24v) track able are going to be mounted as a fixed ground array and the "grid tie" arrangement is to be reconfigured also to a north facing fixed 6 x 24v x 230 watt. The "grid tie" array is almost never needed. So,, if anyone is interested, I have a repairable genny and a good tower going begging. (Bottom of South Australia) David M. |
||||
AMACK Senior Member  Joined: 31/05/2009 Location: AustraliaPosts: 184 |
Hi david, Not good to here that you have given up on the wind.. Will have to catch up some time been out of wind and solar for a bit byt getting back into it now as I got a new hot water system that I am putting in its 30 evacuated tubes and a 370 lt tank.. Had a bit to do with those mills in the past too.... *Note to self 1. Make it thick 2.Make it heavy. 3.Make it stronger than it should be. 4. Don't rush the first job as the second job will cost more and take mor |
||||
| domwild Guru Joined: 16/12/2005 Location: AustraliaPosts: 873 |
Great idea and nice photos. The maintenance issues with wind vs solar are a problem and if the panels become cheaper with time this will exacerbate the issue. One would have thought no sun means lots of wind, but no in your case! Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up. Winston Churchill |
||||
| MOBI Guru Joined: 02/12/2012 Location: AustraliaPosts: 819 |
It is surprising how often the wind doesn't blow and the skies are overcast - hence only about 20% solar at best, and not just over small areas. When I first installed our solar, the panels were 80watt units and cost around $850 each. I thought a wind generator backup would fit in nicely. It did a lot of spinning but usually, the sun was bright enough to keep the batteries charged. If the wind generator wasn't performing (which was most of the time)I used to run the petrol generator for a half hour or so to top the batteries up before going to bed. The long and the short of it is that solar produced most of our power. We fitted a 1kw grid tie system that "talked" to our 24vdc 240vac inverter but it spent most of its time in la la land because the 24v solar system produced most of the power. When the wind generator nearly took the end of my thumb off whilst I was trying to separate the rotor and stator for repairs (yet again) I decided to revert to my favourite "kiss" principle and stick with a non tracking solar array with enough capacity to charge the batteries regardless of sun. I have mentioned before a web site that extracts and presents the eastern electricity grid data. Having a play with it for a couple of weeks gives quite an insight to the vagaries of weather based power production, particularly on a large scale. The data can be extracted directly from the AEMO web site, but needs a great deal of XL-ing. This site also combines BOM data for comparison. I would be interested to hear opinions/questions. AEMO data electricity grid david m David M. |
||||
yahoo2 Guru Joined: 05/04/2011 Location: AustraliaPosts: 1166 |
Hi David, My analysis was a bit simpler. the question I wanted to answer was how much storage? what is the minimum sun we get? Basically I looked at all the records for South Australia on pvoutput to see if I could find 3 days in a row with almost no power generated. I found one, and later realised the grid was down from the massive storm for 2 days in the south east so that ruled that one out. Even on the days that were cloudy the panels produced something and this was looking at grid connected systems that are mostly low angle and north facing. the conclusion that I come to is that with some tweaks in panel direction and angle to catch sun for the whole day and extra panels, there is no place in SA that would have drained the batteries over more than two days in the last ten years. I dont think it is worth the expense or effort to cater for a 1 in 3653 day event. Of course this only works in our climate, all bets are off for areas with a summer wet season. My latest version/solar setup generates 3kwh for every 1kwh of battery (usable capacity) on the average sunshine at the winter solstice. The starting point for me is 40% panels facing NE, 40% NW and 20% North. The number and direction of panels is tweaked to cater for local conditions and daytime power use. I asked someone the other day for his impression of how things were going, he shrugged his shoulders and commented that most days the batteries are full by 9AM and they run the generator for 5 hours last year to power their clothes dryer and to make sure it still worked. Personally I dont think we need to justify using wind turbines. If you want one to play with, then just do it! they can be incredible fun. turbines are like Ferrari motor cars. present day solar is like an old cheap Toyota Camry. on that scale, practical energy management in the future could be compared to an electric bicycle. I'm confused, no wait... maybe I'm not... |
||||
Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
My system has more solar panels than I need, 20 panels, 3800 watts. To give a nice long battery charge cycle, I've pulled the fuses on 6 panels ( 1140 watts ), on sunny days I just dont need them. Even if its lightly overcast 14 panels is enough to do a full battery charge cycle, but if its heavy overcast, I put the fuses back in and this is enough to feed a few hundred watts into the system. This may happen once every two month or so. It may not do a full charge cycle, but does give enough to get me through the night if there is no wind. So with my panel count, I wont run out of power even if its heavy overcast, but this isn't good for the batteries long term. Lucky its a rare event. I also have a wind turbine, and its the battery saver. About 30% of the time, there is enough wind here at night for the turbine to pump out 100 to 300 watts. I live alone, and if I'm watching TV, cooking dinner, etc, I dont draw much over 300 watts while I'm awake, and around 60 watts while I'm asleep, most of this is inverter idle current, a clock radio, fridge and a few other low power items like smoke alarms, etc. So the wind turbine is basically supplying my power needs many nights, meaning less drain on the batteries. If its been a windy night, the battery charge cycle is very short the next day. Since a batteries life is affected by the number and depth of discharge cycles, every night the wind is blowing is a extra day I get out of the batteries. So my view is, if you can harness the wind, especially at night, then do it, because it will give a longer battery life. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
||||
 Print this page |
