Home made wind turbine using hub motor?

[oigoi]

Hi I am looking at making a wind turbine using an old hub motor as the generator. Any of you got any experience of anything like this? Would I be better off using a direct drive motor or could I use a normal one and jam up the freewheel somehow?

 

[Old_Dave]

What a great project... 1st thought is that a single phase motor would be simpler to manage the output rather than a 3 phase (maybe). Blades can be cut from a length of plastic pipe, there is a video on YouTube


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[neptune]

Wind generators are a subject on their own. Using a hub motor will not probably be the most cost effective way to go, unless you have a scrap one laid around. You must remember that a hub motor needs to be supported on both ends of the axle. You will need qiute a lag#rge wind rotor to turn it at full output [250 watts?] Probably 10 feet diameter.No need to mess with the freewheel, it will generate whilst turning backwards. Remember that it will probably run 24/7. so it will soon wear out a set of bearings. Actually, using the three phase output to charge a battery is quite simple. You just need a three phase bridge rectifier. Buy one, or get one out of an old car alternator. With a ten foot rotor, you will definitely need a governor to shut it down in high winds. Do some research. Please ask if you need further info.

 

[Deleted member 4366]

I built a three-phase one from scratch about 7 years ago based on the instruction book from these people.
Hugh Piggott's blog | Scoraig Wind Electric News
I carved the blades from solid (cedar I think) using their instructions and an incidence calculator that I downloaded from somewhere. It was about 5ft diameter and produced about 100w max.

There were a couple of peoblems that I disn't manage to overcome because you need a good installation location. I couldn't get it high enough into the wind and there was a big voltage drop down the wires, so I lost a lot of power before it got to the battery.

If you want power for a house or the grid, you need to go up to about 10ft diameter with as high a voltage motor as you can get to keep the current and hence voltage drop) down.

Mine was only an experiment. I was thinking about moving to a croft in Scotland and going off grid. I still have the wire and the magnets to make the full size version, but I don't think I'll use them now.

One other thing that you need to think about, which I didn't have because it was only experimental. You neeed a furling mechanism of some sort to tip it out of the wind when the wind blows strong otherwise it'll self-destruct. Have a look at this link, where I got a lot of useful info.
Wind Articles

 

[Jeremy]

As d8veh has pointed out, Hugh Piggott is the real guru on DY wind turbines. Not only do his turbines work well, he's been relying on them as his only source of electricity for a couple of decades now.

You can certainly convert a direct drive hub motor into a wind turbine easily enough though, as electrically these motor are reciprocal devices, so will work just as well as alternators as they do as motors. It's just a question of matching the motor to the size of wind turbine, to get it spinning at the right sort of rpm to get best efficiency.

One slight snag with using hub motors like this is that they generally like to work at a fairly high voltage, so they aren't usually that great as low voltage wind turbines (i.e. 12V). Somewhere I had a description or link to a wind turbine built using a Crystalyte 400 series hub motor as the alternator, but I can't seem to find it right now.

 

[SRS]

We have several friends around with home built versions.

Do a little research on treadmill motors, these perform well. This option would be a somewhat easier conversion over a hub motor.

Of course, you would get something from a hub if you have no desire to purchase alternatives.

Overspeed can be dealt with using a simple spring loaded air brake, alternatively switch in a dump load when required.

You can expect around 20amps charging a 12v system in around 20 knots of wind. Twin or triple blades of no greater than 1 metre diameter.

10 knots or less is really a waste of time on small un geared generators.

 

[oigoi]

Thanks for all your input folks, I will do some more research and let you know how it works out

 

[Ajax]

I prefer vertical axis designs myself, here's a few VAWT's for you to look at...

Barrel Wind Turbine - YouTube

Savonius 50 RPM - YouTube

Vawt wind turbine - YouTube

Eolico 5 Kw - Helix Wind - YouTube

wind turbine vertical axis rotor - YouTube

 

[Scimitar]

I think I'd feed the 3-phase output into a transformer at the head of the pole and conduct it away as near to 250V as possible, feeding an immersion heater in a central heat store as year-round, round-the-clock low-grade heating which will provide a significant contribution to the overall energy needs of the building.
Rather than mess around with inverters, battery banks, rectification, speed control, output control, etc, etc., all of which add significantly to the cost.
If I was totally off-grid, that would be different, of course.

 

[oigoi]

I live off grid and in winter I don't get enough power from my solar panels. Like the idea of putting the 3 phase output through a transformer to reduce losses over a distance. Turbine will need to be about 30m away from the house and I'm not sure about what the losses will be. Need to charge 24v lead acid battery bank. Like the idea of vawts also but have yet to see a video of a home made one making a decent power output

 

[Hero Eco]

I used to work in the wind (turbine) industry, and we used to put up huge 121ft(to tip) turbines, the one on the M4 at Reading being the most prominent. Location is key, windspeed, turbulence etc etc. Before you go to too much effort building something, I'd check you have somewhere suitable to install it. We often looked at domestic installations as a growth area, but in reality 95% of domestic locations weren't suitable, even if they were, they wouldn't create much energy.

Good luck with the project!

 

[flecc]

We often looked at domestic installations as a growth area, but in reality 95% of domestic locations weren't suitable, even if they were, they wouldn't create much energy.

Yes, there seems to be a consensus that wind is the least productive of the domestic energy creation systems, very rarely worthwhile.

 

[Old_Dave]

Turbine will need to be about 30m away from the house and I'm not sure about what the losses will be.

Losses in transmission over such a short distance bearing in mind the low current generated will be insignificant if the cable is sized correctly (hint.. don't use cheap bell wire ) if you decide to get involved with transformers then remember that they are not 100% efficient so that could well be unnecessary losses.

Maybe if you have wind then KISS is better... car alternator - split charger - batteries, else add more solar after working out the payback time.