Thread: Wanted: 20m or taller steel street light pole....

Hi Joe,

I think a wind turbine would be an awesome way to compliment an already wonderful property in keeping with your sustainable and energy efficient home. I also have no doubt you will be putting a huge amount of that grey matter of yours into use when doing your calculations, costings and viability with such an endeavour. I also really admire your "can do" attitude too. WRT the pole, I got nothing to offer I'm sorry but good luck.

Simon

Bending the tower in the middle with the turbine blades attached is IMO a recipe for damaged blades.

Why is that? You know the usual way to get a small turbine up or down is to use a gin pole to raise/lower the whole pole/tower, with the turbine attached. A mid-hinged pole allows you to do that in a much more controlled fashion because the other half of the pole acts as a counter weight with the cable hanging off it. It's actually a great way to do it with a small turbine. You can lower it down backwards too, so the blades are facing up.

Hi Joe,
1st. up, as I'm a little unhappy that I'm going to miss the Bendigo Swap this coming weekend. So for all you lucky people good buying.

Well the likes of Powercor, are always replacing Highway Light Poles, that have been hit.
As you are aware they are on a taper, so getting them apart is not a big problem. You may have to get a few to make 1 Pole. I wood think Powercor wood have some on their block somewhere, out White Hills way.
What if you cemented in 2 C Channel uprights put the pole in between, & with 2 bolts, for holding, & you wood need 3 Steel Guy Ropes to hold it up straight.
With 1 of those Bolts removed you wood, with great difficulty be able lower the pole, for maintenance.

Just my thoughts?????.

Originally Posted by issatree

What if you cemented in 2 C Channel uprights put the pole in between, & with 2 bolts, for holding, & you wood need 3 Steel Guy Ropes to hold it up straight.

Hi tree,

Do you think there would be enough room for guy wires given the turbine blades? I guess with 3 points at 120 deg separation they may just miss the blades?

Hey Joe, if a single large(ish) wind turbine proves very difficult, had you thought about maybe 2 or 3 smaller turbines? You could start up the Hovel Wind Farm!

Simon

Originally Posted by silentC

Why is that? You know the usual way to get a small turbine up or down is to use a gin pole to raise/lower the whole pole/tower, with the turbine attached.A mid-hinged pole allows you to do that in a much more controlled fashion because the other half of the pole acts as a counter weight with the cable hanging off it. It's actually a great way to do it with a small turbine. You can lower it down backwards too, so the blades are facing up.

I didn't know that.

I'm wondering how you align the turbine blades in the right orientation, and stop the turbine rotating as the pole is lowered?

But if the tower needs to be 20m high to get above the trees, and a bit of Googling suggests a 2kw turbine will weight about 90kg -- the loads on a steel pole are going to be significant.
There used to be two wind turbines on the road between Jindabyne and Thredbo -- after a strong blow, there was just two piles of twisted metal.

Interesting thread. Has anyone asked why would anyone want to go through the trouble and expense (would $10,000 be enough?) to set up a wind turbine that when the wind blows will produce ... what was it again? ... that little?

How much is 1.5kw/h in money terms?
How much to repay the cost of the turbine, considering windy days are ... mm ... how many a year?

I would rather buy a boat and go fishing. Sustainable fishing that is...

If you have a good site for wind it is cheap and viable.......but if you do not have a good site for wind it gets very expensive and pointless very quickly.

If you have to think about getting above the tree line ya probably better spending on more solar capacity and making electricity while the sun shines.

Unless of course you are "prepping" for a volcanic or neucular winter.

cheers

How about this mast...
http://www.ebay.com.au/itm/Wind-Turb...item3a9ae18bd7

Originally Posted by cba_melbourne

How about this mast...
http://www.ebay.com.au/itm/Wind-Turb...item3a9ae18bd7

well that's probably one of the most helpful posts yet! Good work!

simon

Hi Joe,

I have some experience replacing damaged light poles. First up most of them are less than 12m tall. Taller ones exist but I have not worked on them and suspect they are mostly hinged in the centre to allow the top to be brought down for maintenance work. I say this because a 20m pole is going to require probably a 25m EWP to allow for not being able to park directly under the light etc. You start to get into difficulties with parking such a vehicle on the side of a road to do the work, (outriggers, size of truck etc, etc.) The wind loadings on a light pole is likely to be much less than what you might require for your wind turbine

As an alternative from time to time, the companies that look after transmission towers upgrade lines etc and often change towers due to, oh, say light surface rust or age, yes age that's it, near the end of their useful life etc. I know this because a local transmission line was recently upgraded. The much larger heavier conductors required much taller towers. The old towers were pulled down and either given to farmers or sold to them at a song or the towers were shredded using shears on an excavator before being sent to the local scrappy. The contractors doing the job told me the new Chinese towers had similar amounts of surface rust as the 40 year old BHP steel towers they took down. Go figure. There were some issues around getting hold of one of these towers. The contractors had OHS concerns. All the parts are numbered and only go back together in one way per side. The towers had been sold to the local scrap dealer. The towers weigh about 3 tonnes each and break down to lengths of angle no more than about 4 metres long. A mate and I left our run a bit late for the towers and missed out. About 10 of the towers ended up a huge pile of bent mangled steel at the local scrap yard, much to my dismay. There is some justice however as they are going to have to spend a lot of time and money cutting it all up to transport it efficiently.

On a separate issue, How are your trees laid out? Can you cut some of them to form a funnel shape to get more wind through the gap? This may lesson or entirely remove the requirement for a tall tower. It may pay to get some measurements of wind speeds, at your site, at several different heights above ground level. If you are looking at a commercial turbine, the manufacturer should be able to tell you the wind speed required for rated output. If you can get that wind speed, regularly at,say, 5m above ground level then it may not be worthwhile going higher. As an alternative can you plant some fast growing trees that would help to funnel the wind?

Cheers

The Beryl Bloke

Yes, Chris, I've tslked to the seller by phone to establish that I was looking at a tower suitable for a turbine. Alas it really isn't. It is suitable for a much smaller wid generator - like 300W or so - as it really is an antenna tower, similar to the one I have here (with my antenna on top).
A 1.5 or 2kW turbine has a 'sail equivalent area' of around 2 square meters and would blow an antenna tower over in quite a 'gentle' storm/wind.

However, I'm startign to get a sense of the structures required from doing more reading and looking at turbines. Coles supermarkets in Hobart, for example have some interesting looking turbines on poles in their car parks. The size looks around 2 or 3kW.

Marc, I have no intention of spending anything like $10,000 on a wind generator installation! I would consider something like $3000 reasonable however. You might think I'm crazy, but then you would not have had any experience of my resourcefullness or tenacity

Beryl bloke, thanks for the information and suggestion of wind funnelling. Both are useful considerations! As it happens, I have a good contact in power supply installations and will be able to ask him to investigate for me. A powerline would actually produce quite large wind loads - maybe he can get me some engineering details in any case....

Still too many variables to make much headway: apart from the pole or tower, foundations, generator, rectifier and inverter, the last sticking point may well be the cost of underground cable for the distance involved (up to 150m incl verticals). I'm obviously considering that to carry 240VAC rather than 24/48/96V to keep the crossection in check, but even then it may simply be too costly (8.3 +A).... might mean 10mm2 cable I'll have to find a bargain for just that I suspect

Marc, I have no intention of spending anything like $10,000 on a wind generator installation! I would consider something like $3000 reasonable however. You might think I'm crazy, but then you would not have had any experience of my resourcefullness or tenacity

Not at all, and I respect resourcefulness and tenacity or I wouldn't still be blacksmithing in an era of iphones and online trading.
However, and using blacksmithing as a simile, what you are doing equates to me wanting to pour a concrete slab and deciding to go mine the rocks and burn them to make my own grey cement and also dig up some iron ore and roll it into bars for then hammer the ridges into them to make my own reo bars. All this not as a hobby, but because i believe the cement company and BHP are doing something really wrong and I can do better yet I am disregarding my own inefficiency and the massive pollution created by all those who have manufactured the parts tools vehicles and other resources I need for my little experiment.

Well that is what I think of the wind industry, however if you have a hobby and the knack of doing things your way ... well ... rather than a massive tower that will cost you $10,000 or perhaps $15,000 at last count, http://www.xzeres.com/wind-turbine-p...urbine-towers/ ...not to mention needing council approval, being the target of neighbours complaints and killing the local fauna with great consistency, why not set up a few smaller battery chargers and a bank of batteries?
Just an idea.

PS
Mm ... 10kw in the best of days ... that is 1/3 of the year, so 1200 kw at 20c a kw = $240 ... $3000/240 = 12.5 years. Of course I don't think you can make 10KW aday with equipment that costs $3000, so the numbers are way worse than that.


Then again if you really must build this contraption, try something cheaper than a monopole or lattice tower.
http://www.energymatters.com.au/sout...5etvj1kj6cbq50

8 amp, 240 v, 10mm square???
more like 2,5 mm square

Originally Posted by jhovel

However, I'm startign to get a sense of the structures required from doing more reading and looking at turbines.
snip
A powerline would actually produce quite large wind loads - maybe he can get me some engineering details in any case....

Dredging the memory from a very long time ago ...
the critical loading on a transmission line tower comes from installing the conductors or when a conductor breaks, not from the wind
the conductors -- typically aluminium or an AL alloy -- are under considerable tension -- if one breaks, the power company doesn't want the released tension pulling down a whole line of towers. If you look carefully, towers where a power line changes direction are much heavier than towers on straight sections