[Axe Victim]

I found this excellent site with plans for home-made wind turbines and the like....

http://www.gotwind.org/index.htm

Has anyone tried wind power on their lotty? I'm half contemplating having a go at a wind turbine to run an irrigation system...I know gravity is easier, but it might be fun!

 

[Celtic Eagle]

Hi Axe

That's a cool site. It's set me thinking sounds like a skip hunt and carboot job to me I could run a small heated propagator off something like that

Worth further investigation

Cheers mate

[Axe Victim]

If you do make something keep us posted....I'd love to hear the outcome.

[GrannieAnnie]

Mmmmm, that looks good.  Must show it to OH!!!  Get him working on something!!

[Axe Victim]

What's the betting we cause a global shortage of old bicycle dynamos now?

[Zak the Rabbit]

think finding them old bike alternators might prove a bit tricky in the UK. Car alternators are easy to get but as noted tend to need bit higher speeds. I do believe old muntjak has a setup using a car alternator. I built one years ago but we never fully tested it. A simple gearing system might be needed.

certainly worth looking into

[Axe Victim]

You can get the bicycle dynamos that run on the side of bike wheels (ie not the hub ones) for a fiver on e-bay...they only put out 6v x 3w...enough for lighting a shed if it's windy and you're not short sighted in gloomy conditions...

At the moment I don't understand enough about the electrics and what on earth 'rectifyers' etc. actually do....is it as simple as....

spin the alternator using wind power (however you mechanically arrange that) and connect alternator to old car battery (which wires go where?) and keep battery topped up that way...then you can run anything that would be run by a car system (cd player, cigarette lighter, lights etc.)

q. Can you 'overcharge' car batteries if they are connected to an alternator 24/7

You could run a heated propagator using one of those in-car kettles.

Also, if you reverse the input to those little 'cool boxes' that you can get in cars...do they become 'warm boxes' ?

 :?

[tully]

Please can some clever devil draw out specific details of how I could use a wind turbine to power a light or heater in the greenhouse...Its costing a blooming fortune in parrafin.

I have even thought of heating bricks and burying them or possible under the bench in the greenhouse....building a frame and putting pure muck in it...would that do the trick?

[shaun]

Its costing a blooming fortune in parrafin.

if you can get kerosene (domestic heating fuel) its more than half the price

[Zak the Rabbit]

ok, couple of bits of info -

rectifiers - these are what we call 'diodes' and they take alternating current (which changes direction every half cycle) and make it direct current (DC, what batteries produce). Problem is that one diode produces pulses because it only rectifies one way. A Bridge rectifier is four diodes aranged in a special loop, and they rectify both halfs of the AC input to give a DC output. But! you then need a 'smoothing capacitor' to act as a reservoir to keep the output constant.

you cannot just connect an alternator to a battery. The charge current for a battery must be DC, so it needs a rectifier. Also, batteries need to be charged at no more than a certain percentage of their capacity, so if the battery is small and the charger big, a regulator is needed (think of this as a 'tap'). In the case of a little charger like these, and connected to a car battery, you can probably get away without a regulator, so,long as the input voltage is below 14.4v


you cant run a light or heater directly from the wind charger, its output will not be sufficient, and even if it was, the changes in wind speed would mean that the bulb would change brightness. This is therefore why we use it to charge a battery, and run everything else off the battery. Most things we want to run take more current than the wind charger gives, so the battery acts as the reservoir, we take what we need in a short burst, and then over a longer time the charger fills it back up.

as the system will be 12v, the lights / heaters etc must also be 12v, so anything designed for a car or caravan is what you should look at. Remember - heaters will be power hungry, it may take the charger a long time to bring the battery back up after a stint with the heater on.

[shaun]

zak can i run my world famous been chopper with a windy thingy ?

[jack russell]

hi

Zak i have read and digested what you wrote  :shock:  

So with all that said,  what alternator and what battery and what size fan etc. will power a 12v caravan type light in the shed on the lotty.

I realise there are many different components out there but just looking for a example of a workable system for the novice type idiot :shock:  

pics and diagrams also would be a help   (pushing my luck)

Cheers

jr

[Zak the Rabbit]

ok, firstly - you dont power the light from the generator, you use the generator to charge the battery, and run the light off the battery. Think of a river feeding a reservoir - the river flow isnt constant, but varies, the reservoir stores the water so you can draw off a constant flow through your tap.

A bog standard car battery is ample for running the sorts of lighting you would need in a shed, especially if you use 12v flourescent lights. The output rating of the generator will determine how long it takes to recharge the battery back to full power. As an example, suppose the generator is rated at 12w, for a 12v output thats 1A. The battery typically will be rated around 30Ahr, meaning you can take 30A in an hour, or 1A for 30h. If you have discharged it down to 20Ahr, then it will take 10h to recharge. So if your lighting takes 10A (unlikely, but good example here) then you will have discharged the battery to that level in 2h.  :?

so the setup is =  generator - regulator - protection - battery -protection - lighting

the regulator is only needed to prevent the charge voltage exceeding 14.4v, and to limit current if the battery is very flat. The 'protection' in the first case consists of a fuse and a diode (the diode stops the battery discharging back through the charger, its a one way valve), the second is a fuse and a switch.

I cant say much about the mechanics of a generator im afraid, you would need to find the average windspeed for where you are, and work out from that the blade sizes and stuff. 'fraid its a bit of trial and error. I can tell you though that if you double the blade length you multiply the output power by a power of 4 (up to the generators limits), at least for commercial 200MW windfarms anyway

zak can i run my world famous been chopper with a windy thingy ?

i dunno, whats its requirements? maybe you need a mechanical wind power for it, like a windmill for beans!

another thing to remember is that whatever size it is, it will need to be mounted on bearings so it can move to face the wind, the heavier it is the less easily it will move!

If you consider a rutland wind charger - they are about the size of a car alternator, the blades are about a foot long, usually 3 or 4 of them. I dont know if they have any gearing inside to change the rotation speed.

Id be happy to mock a test bed version up if i had the parts, and could then test it see how it works. But ive no parts to do it with at minute.

[Zak the Rabbit]

ooops, sorry jr, didnt read your post correctly, missed the bit about the battery. :oops:  you can ignor my first sentence! :?

[Aidy]

just another thought, going back to the question can u keep the battery on trickle charge without damaging it , would it be possible to run a invertor so now producing 240v and run this on a daily basis without killing the battery?