MPPT for commercial wind turbines

[poco dinero]

Hi all,

The Midnight Solar Classic is finally available.

I'm wondering if it would improve the performance of my two commercial wind turbines.  Halfcrazy participated in beta testing and he once posted that he was seeing 2500 watts from a DanB Homebrew 10 foot wind turbine, which is essentially a 900-1000 watt machine without MPPT.

I'm not looking for that much improvement, but here's my setup.  The 2kw Exmork wind turbine is a radial flux, commercially produced machine with a 12.5 foot (3.8 meter) rotor.  It furls when the wind hits about 35-40 knots.  It comes with a "controller", but that controller is not an MPPT controller.  Its simply a metal box that contains the rectifier, the kill switch, a couple of panel meters, and dump load control circuitry that feeds a bunch of relays.   

Does anybody out there have an expert opinion regarding how much improvement I could reasonably expect to see if I stuck a Classic between my wind turbine and its present (Chinese) controller?  Is that the right place to stick it?  I'd like to hear it from boB or Robin, but other expert opinions would be welcome too.  I'd be willing to buck up for a Classic (or maybe two of them) if I could be assured of a 20-25% improvement, although these wind turbines are no slouches without MPPT.  I frequently see over 3 kw from them, without MPPT.

I've queried my usual RE supply house, but they don't know. 

poco

[SparWeb]

I think the obvious answer is "time will tell".  I've no reason to doubt that the Midnight Classic won't offer advantages to some users.  Are you on the waiting list for one?

To gauge what it can do for you, without field experience with that one, look for what people's experiences are with similar devices.  Rob Beckers may be able to tell you something if you contact him and tell him about your turbines.  He may have done some comparisons with the Aurora and other non-MPPT inverters.  It will depend a lot upon the design of the turbine and how the generator power curve "matches" the rotor.  Turbines wound for low-voltage DC battery charging will not benefit as much as turbines wound for high voltage AC grid-tie, I expect (you probably already guessed that).  If you want to contact Rob you can find him at www.solacity.com

[cdog]

I have been reading all I can about this, I also joined the midnite solar forums.
What I am curious about is will the turbines be running much faster than intended from a tsr point of view?
Will they be noisy and will the tips of the blades start to erode??
As far as performance improvements go, I have to say I am sold...

[cdog]

I see the bergey 1kw machine is being sold with the classic, how similar is it to your machine?

[cdog]

They have also reported 9kw from a 17' axial using two classics, thats a lot of juice!

[halfcrazy]

I have been reading all I can about this, I also joined the midnite solar forums.
What I am curious about is will the turbines be running much faster than intended from a tsr point of view?
Will they be noisy and will the tips of the blades start to erode??
As far as performance improvements go, I have to say I am sold...

Actually the blades will spin faster but that's the point a typical turbine like my 10 ft machine the blades will be held back by the battery voltage thus being below there optimum tsr. With the Classic the blades get to run at there optimum speed in all wind speeds thus becoming much more powerful. I have a Bergey xl1 on the pole now testing there new stator and Classic combo and it is impressive.

We have routinely seen 9kw out of the 17 ft machine at my neighbors this is running at about 150-170vdc so it is spinning right along. I took my 10ft machine down a couple months ago to install the Bergey xl1 and the blades had 3 coats of linseed oil on them when purchased from Dan and have not been touched for 3 years over 2 of those was running into the Classic. I do have a little leading edge erosion but it is minimal and I suspect caused by the super dry cedar and my lack of maintenance.

[cdog]

Thanks for the understanding of the tsr, makes perfect sense now.
Was the 17' originally wound for say 48 volt. or was it wound specifically for the classic?