Wind generator tower, stage 2

Heh heh, here it is:


Put together from water pipe that I had lying around. Four pipes up to about halfway, then three pipes all the way up to 5.5 metres above ground. The turbine itself will be about 6.5 metres above ground.

The individual pipes are not strong, but they will be strapped together. I might use predrilled galvanised steel strap and tek screws. I might also put in guy wires to about halfway, just in case.

The wind generator kit has its own tower with hinged base and that will be used. The idea is, it will be hinged at just above the level of the shed roof, so I can assemble the wind generator on the roof, then rotate it up vertically! A pulley mounted on the top of the pipes will be used for winching. Alternatively, 3 or 4 blokes could probably lift it up. After it is vertical, some bolts can go through the pipes to lock it all together.

The basic idea is that it is serviceable. I can winch it down at any time, without having to hire a crane.

My original "stage 1" post:
http://puppylinux.com/blog/?viewDetailed=00070

Posted on 9 Aug 2008, 8:28


Comments:

Posted on 9 Aug 2008, 8:30 by dogone
Wind power
Perhaps you've already shared this, but are you all set to go with respect to batteries and electronics? Do you plan to tie your wind machine into the mains or utilize it as a separate power source (for the computers, for example)? What's your utility company have to say about the arrangement? Any restrictions?



Posted on 9 Aug 2008, 8:46 by WN2A
Guy Wires
Barry,
Without question, guy wires=piece of mind.
With my ham antennas, they are indispensable.
With your turbine,necessary.
73


Posted on 9 Aug 2008, 10:29 by John Biles
The Dangers of Waterpipe contruction
Hello Barry K,
It's generally know not to use waterpipes for structures as it doesn't bend but snaps.
Besides experimenting with Linux and Electronics, I have also built an ADR approved Chassis.
When they started putting roll cages in vehicles in the 50's and 60's, some racing drivers where killed because they were speared by their water pipe roll cages in a crash.
So if the wind is blowing, don't stand under your generator.


Posted on 9 Aug 2008, 16:26 by RickRandom
A few thoughts re strength
If the diameter is say 2m (guessed at for 300W) and max windspeed is 60mph, then max wind force is about 1250N (swept area x dynamic pressure). You need to allow some safety factor, say 2, so you need to decide if the tower could take a side load at the top of 2500N or quarter of a ton.

If it's a bigger area, then the loads go up proportionately, if the max wind speed is higher, then the load goes up with the square of the speed, so 10% higher wind speed is 21% more force.

Presumably the machine has an automatic system to prevent overloading in high wind (furling?), so the instructions should state that max speed.

Getting the tilting tower up will also put a lot of side load on the hinge point. If the "gin pole" is half of the hinged length then the side load will be double the turbine/generator weight, so guessing 50kg mas = 500N weight, doubled is 1000N, then safety factor.

Don't hurt yourself, you're too valuable!


Posted on 9 Aug 2008, 17:04 by BarryK
Re: water pipes
I have already decided it's not strong enough to be entirely free-standing. It will definitely have guy wires.

The high wind protection of the turbine is quite primitive, it is just set off-centre, so the higher the wind the more it turns to the side.

What I could do is have a wind-speed sensor that shorts out the turbine, that is, imposes maxmum load, which should slow the blades right down.
The user manual recommends a manual switch to do that, but it would be prudent to have it automated.

I'm building this on the "suck it and see" principle.


Posted on 9 Aug 2008, 18:09 by ANOSage
Wind power
"suck it and see", depending on local weather expectations, may not be expeditious? Abandon the old water pipes before it's too late! It is possible to buy some s/h scaffold as a job lot from most builders merchants cheap, especially if they're showing superficial rust which would not pass building inspections; a wire brush and tin of zinc paint is all that's needed. It may be possible to scavenge and recondition some suitable materials from the old mine works not too far from you? Usually, the cost of transport is greater than the items. Build a proper tower. The base/foundations and anchorage are as important, as with all constructions, as the edifice above ground. I asked about how the blades will be feathered previously? Design needs to anticipate the once-a-century gale force wind. If blade pitch isn't controllable, best to physically lower the turbine with block-and-tackle. Wouldn't rely on electrical damping - the blades could break off and penetrate your house. They built experimental wind turbines in the USA in the 30's. These were abandoned after the shafts of some broke off in gales and went tumbling 20-30miles across country before coming to rest. I remember a colleague calculating the force on washing hanging on the line in a good breeze - Rick's numbers give a flavour of the problem. When something breaks, all those kW are translated into potential and/or kinetic energy looking for a home.


Posted on 31 Aug 2008, 23:46 by Aitch
More Wind Info
Hi Barry
I am a subscriber to SEGEN Newsletter here in UK
I thought you might find this link useful, as I see you are pitching yours near your shed
http://www.segen.co.uk/eng/wind/faq/index.htm
There are other links at the bottom of the page which may be useful to you also
Good Luck - hope you have a supplier of traction batteries and a charge controller :)
Aitch