View Full Version : I want to build a wind generator.

1st Mar 2006, 15:18
Having just had the electrickery company reset my prepayment meter to a silly rate/unit I have decided that I will use the wind, plenty of which we have in the Fens, to drive an alternator, thence to a leisure battery and into a inverter.
I intend to only drive the lights, as I have a number of these which are on all night. They all can have low power bulbs, and at rough guess a 600 Watt thingy should do the job.
The battery and inverter will run to about 160. An alternator can be procured from a tat yard, the only problem I have is the actual blade profile/construction and a form of governor for when the wind BLOWS hard.
I saw a device somewhere with a 50 Gallon oil drum chopped about its vertical centre line and welded side by side. Does anyone have any SERIOUS observations on this.

bar fly
1st Mar 2006, 15:21
Gutted. My post was busted by your final sentence. :(

1st Mar 2006, 15:24
Same here.
Had several suggestions regarding your MIL up my sleeve. Never mind.

Off the subject, are you & Mrs Jones joining us for a drink tomorrow?

1st Mar 2006, 15:25
Is this to power your house or the massive model railway in your attic?

tony draper
1st Mar 2006, 15:37
Might be easier to buy a small deisel generator, pity you didn't post this earlier one gave one away just a few weeks ago.


1st Mar 2006, 15:38
Technically, an oil drum cut in half like you describe is a friction device and not an aerofoil but hey-ho. It will work but the output torque that drives the alternator will vary greatly with wind speed and therefore the voltage it produces will too. This leads to enormous inefficiencies in the production of electricity.

Commercial wind turbines often get around this by having variable pitch on the blades. At low wind speeds the AOA is quite high to get max power out of the wind and at high speeds it is feathered to stop, amongst other things, blade vibration (which can shake the thing to bits) and noise.

One advantage of using the drum is that you don't need a fancy mechanism to point it into the wind if the axis of spinning is vertical. However, a vertically mounted drum would produce high stresses and bending moments at the point which the shaft connects to whatever you're bolting it to. A horizontal axis of spinning does need to be steered into the wind but is more stable as you are effectively mounting the drive shaft at both ends. Heh heh, I said " shaft".

Not sure if this answers your question but it does exhaust my knowledge of old-oil-drums-being-used-as-power-generators-to-escape-tyrannical-power-delivery-companies.

Edit note: Try this one in the Engineers Forum...

1st Mar 2006, 16:05

One saw the title of this thread and immediately thought of beans

Onan the Clumsy
1st Mar 2006, 16:11
Just for foxtrot

http://i.imdb.com/Icons/poster_under_licence.gif (http://www.nostalgia.com/nf_moreinfo.html?sku=49419)

1st Mar 2006, 18:35
First link on google for wind generators.
At least you know that it'll work;)

Standard Noise
1st Mar 2006, 20:47
Mrs Noise says I already have a wind generator, modesty forbids me revealing it's location.:}

tony draper
1st Mar 2006, 21:27
I can see it now ,you get it built and it works, then the weather report.
"The metreological mystery continues, where has the wind gone,?the county enters its second month with no wind whatsoever"
Thats whart would happen to me anyway.

Windy Militant
1st Mar 2006, 21:53
Hello Mr Jones there's some info here that might help. CCLRC Energy Research Unit (http://www.eru.rl.ac.uk/Further_info.htm)
You could also try googling MARLEC.
There's a chap on one of the Scottish Islands whose name escapes me who sells plans for a home built turbine based around a Lorry brake drum.

Apparently a lorry Fan will make a suitable rotor for a small turbine. It's a bit inefficent, however it stall regulates at a low enough speed to prevent the alternator exploding from over speeding. Most small turbines are controlled this way basically you set the angle of the blade to stall at the maximum output speed of the alternator. You lose a certain amount of power but it means no moving parts so low maintenence and less cost. Some marine turbines also include a luffing mechanism which uses a movable fin which tilts the rotor out of the wind when the wind speed reaches a certain value to prevent overspeeding.
The hardest part for home builders is getting decent sliprings to transmit the power down from the turbine to the ground. Although some designs do away with slip rings and just leave a bit of slack in the cables but this means that you have to keep an eye on them for twist and periodically untwist them manually.

1st Mar 2006, 23:10
If my memory serves me correctly you are looking for a Savonius Rotor, first saw mention in a mid seventies prog on BBC2? hosted by amongst others Lynn Faulds Wood? in a precursor to the current fad of DIY property improvement/development programs

Try a Google search - one response is


also possibly Amazon .co.uk

House for the Future by Terence McLaughlin

1976 was a long time ago!!!

PZU - Out of Africa

2nd Mar 2006, 02:57
I have found that the best way to generate wind is to consume a tin of Baked Beans and about six sticks of licorice:\

Buster Hyman
2nd Mar 2006, 03:27
Needs to be Environmentally friendly AntiCrash.http://www.clicksmilies.com/s0105/spezial/Fool/fart.gif

Now, I've often wondered why one couldn't simply rig an electric fan in front of the wind turbine & turn it on. Once the turbine is spinning sufficiently, switch the fan to the supply from the turbine & voila!http://www.clicksmilies.com/s0105/spezial/Fool/thk.gif

henry crun
2nd Mar 2006, 06:40
SpeechlessTwo showed what can happen with an equipment failure.

This shows what can happen when mother nature decides to get stroppy. :)


2nd Mar 2006, 07:19
A house featured on Grand Designs has a collection of 2V submarine batteries which are charged by wind and solar, and then uses a DC/AC inverter to give 240 mains power. The losses in the system are quite large - about 40% I'd guess.

Have you done the calcs? A 100Ah leisure battery will power a 500W load for about 40 hours before needing to be re-charged.

Mr Lexx
2nd Mar 2006, 07:59
Now, I've often wondered why one couldn't simply rig an electric fan in front of the wind turbine & turn it on. Once the turbine is spinning sufficiently, switch the fan to the supply from the turbine & voila!http://www.clicksmilies.com/s0105/spezial/Fool/thk.gif

Ah, the old perpetual motion debate :ok: