A suitable alternator/dynamo for small VAWT prototype

[prototype]

Hi, I'm currently doing a VAWT prototype.

I'm happened to find these 2 alternators, but not sure which is better?

http://www.ginlong.com/wind-turbine-pmg-pma-permanent-magnet-generator-alternator-GL-PMG-500A.htm

http://www.windbluepower.com/DC_540_Low_Wind_Permanent_Magnet_Alternator_p/dc-540.htm

the dimension of the Savonius turbine, height is 0.8m and width is 0.43m

My system require a low starting torque and low friction alternator. Previously, I've purchased one from http://energistar.com, but the performance was far from the information given.

I hope the alternator able to generate 12V and more than 1 or 2Ampere at low rpm, and low torque required. Any better suggestion than these 2 alternators are welcomed.

or something like this, http://www.gotwind.org/diy/Axial_Flux_Alternator.htm

or a dynamo with higher power??

Any idea??

Yes, my idea is you discuss this in your original post [under a different ID] elsewhere.

[electrondady1]

your link to energistar doesn't work for me.

[Todd a]

The first one has a lower speed requirement, but does not list the price.

What I am temped to try is a car alternator with a centrifical switch.  When the wind generator hits a certain speed it will allow a battery to flow power to the alternator to power the magnets for a tiny bit.  After that it can power itself and generate power just fine.  This would let me use a much cheaper alternator (with rectifiers and voltage regulators built in) that is also much lighter (electo-magnets instead of PM).  This would also have a lot lower mass to spin up than most wind generators and not apply a load until it can actually take it.  The drawback is the requirement of the switch and battery, a low voltage high amp wire so you would need thick cables(making it require having the battery and inverter very close), and a pulley system as car alternators require a high RPM.

I wonder how much power an alternator needs to start.... maybe I could use a tiny PM generator to power it up instead of a switch and battery.  Then it could be self contained.