Thread: Windmill energy into usable power?

Originally Posted by bee utey

Belt drive a 12V alternator off an alloy racing bike wheel (nice and narrow) mounted to the bottom of the shaft. This can help power your independent 12V LED lighting system and already has an internal regulator. The alternator would be mounted pulley face down and be covered against direct rain ingress.

Is the windmill a spinning shaft? I thought they reciprocated up and down.

Originally Posted by gavinwibrow

Thanks all - fascinating stuff, and maybe one day Dave won't have a ready answer to hand.

I hope I'm not highjacking this wonderful thread, but it is related.

I always understood that wind power was not terribly suitable for camping type arrangements ie did not generate much power in small/highly portable units, including those fitted to caravans, but it sounds like there have been a number of improvements.

A thought - I'm seriously thinking of adding a positive air pressure system to my caravan to aid in dust minimisation for when we finally get off the bitumen.
I could
(i) just connect the positive air electric fan motor to the car Anderson plug, or
(ii) maybe add a small power fan to the van to both run the positive air, and also operate whilst stopped and disconnected. In turn this could operate the positive air system like a reverse exhaust fan and provide additional internal van air movement when aircon is not warranted (but of course only when the wind is blowing), or otherwise additional air via connection to the van battery.

Then again, I'll probably get shot down by being told the fan could not generate enough power to run the positive air anyway?

Or that the additional fuel use via extra wind resistance for the generator fan would negate any benefits - but then again I'm pulling a big brick at 80 -90 kmph max, so?

yes and it works well, the trick is making sure that the fans flow rate exceeds the leakage rate of the van. This system is exactly how the NBC filtration system on most armoured vehicles works. Printer cabinet fans and car air cleaner assemblies are you friend here.

Originally Posted by Sitec

As for the windmill, I'm trying to work out if its worth making the one I have generate electricity. It is going to form a large illuminated garden feature at the new place (as it did at my last place). The mechanics of getting a spinning shaft to the base of the tower without the need for slip rings etc is the easy bit.. Its knowing/working out what is the best way of generating power from a vertical shaft that spins at a guesstimated 100 - 150 rpm when the wind blows that I'm not too sure about...

easy, use an automotive alternator and a pully system that steps up about 15:1 that will keep the shaft speed between 1500RPM and 2500 Rpm.

What happens if the wind is very strong - does your system shake itself to pieces? Most wind generators are governed.

Sent from my SM-G900I using AULRO mobile app

Mick , they have a gearbox with a pitman arm type assembly to convert rotary to linear motion.

Originally Posted by Mick_Marsh

Is the windmill a spinning shaft? I thought they reciprocated up and down.

You are correct Mick. Normally they do reciprocate up and down, but the gearbox atop the tower is large enough to house a ring and pinion.. I was thinking of removing the crank setup and replacing it with an R&P.. By doing this I'd end up with a spinning shaft, and negate the need for slip rings, as the windmill would 'walk' around the R&P when the wind changed direction...

Originally Posted by bee utey

Belt drive a 12V alternator off an alloy racing bike wheel (nice and narrow) mounted to the bottom of the shaft. This can help power your independent 12V LED lighting system and already has an internal regulator. The alternator would be mounted pulley face down and be covered against direct rain ingress.

This was along the lines I was thinking.... but was thinking of using a dynamo so I don't have to find myself the 12v required to excite the alternator.... (Tho I guess that could be done with a solar panel....?). This would be all mounted in the ceiling of what is going to become an entertaining bar/pub under the windmill! It'd make door some interesting conversations on a windy night!!

Originally Posted by DiscoMick

What happens if the wind is very strong - does your system shake itself to pieces? Most wind generators are governed.

Sent from my SM-G900I using AULRO mobile app

I've no idea... yet.. Guess we'll find out! I'm not sure how, but in high winds the windmill only seemed to get to a certain speed... It never spun so fast that it shook.. I was told they pull themselves out of the wind at a certain point but could never see how that would work....

Originally Posted by Sitec

I've no idea... yet.. Guess we'll find out! I'm not sure how, but in high winds the windmill only seemed to get to a certain speed... It never spun so fast that it shook.. I was told they pull themselves out of the wind at a certain point but could never see how that would work....

I thought that windmills have a spring on the tail plane to tilt it out of the wind in a storm.

This was along the lines I was thinking.... but was thinking of using a dynamo so I don't have to find myself the 12v required to excite the alternator.... (Tho I guess that could be done with a solar panel....?). This would be all mounted in the ceiling of what is going to become an entertaining bar/pub under the windmill! It'd make door some interesting conversations on a windy night!!

A bank of deep cycle batteries plus a solar panel or six will complete your home power station. Having your own power available when the neighbours are reduced to candles is quite satisfying... a hot summers night, a thunderstorm takes out the local HV feeder, and you've got cold beer in the bar fridge...