Author Topic: Low wind chinese turbine options  (Read 8351 times)

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stephendv1

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Low wind chinese turbine options
« on: February 25, 2013, 03:56:53 AM »
Hi all,

I'm new to this forum and have some questions about chinese turbines.  I live on an off-grid farm in Northern Spain with 2.8kW of PV and a 900Ah 48V battery bank.  We've only had to use the petrol generator for a total of about 20 hours this year as the solar works very very well.  But now I'm considering the potential to use solar + wind for water heating and space heating in the house during winter and so am considering a chinese turbine.  From what I've read, the exmork variety seems like a good bet and after mailing a few companies I've received the best offer from Ningjin Huaya industrial who say they are the factory.  Their turbines look the same as the exmork/senwei and have the same specs, at a lower price.

They offer a 2kW turbine with the option of a 3.2m rotor (standard) or 3.8m rotor for low wind areas, I've asked about this and they say that the latter also has a modified tail vane.  Since we're not in a great wind area, I'd prefer a turbine that generates more at low speed and less at high wind speed, so this option seems ideal.  Except I'm not sure whether to trust that this arrangement will work.  Can a bigger tail vane really furl a substantially bigger rotor in high winds?
They don't have any specs on the 3.8m 2kW turbine, but they do have for a 3.8m 2.5kW machine, which is a standard model.  Can I expect more power in low wind from a 3.8m 2kW than from a 3.8m 2.5kW ?

DamonHD

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Re: Low wind chinese turbine options
« Reply #1 on: February 25, 2013, 06:04:16 AM »
Hi,

Welcome to Fieldlines!

A grown-up who actually knows something about the topic will be along soon, including the usual caveats about there simply not being much power in low winds to overcome system losses, and how heating requires a lot, etc, etc.

Rgds

Damon
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ChrisOlson

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Re: Low wind chinese turbine options
« Reply #2 on: February 25, 2013, 08:16:05 AM »
Without seeing the specs on those turbines it's really hard to say.  But in general, the larger the rotor the more power you will harvest, at any wind speed.  The Exmork turbines are reasonable quality, and quite heavily built machines - I think they are a good buy considering what they cost vs durability.  They have been known to have some problems with their electronics, but mechanically they are a pretty solid wind turbine.
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clockmanFRA

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Re: Low wind chinese turbine options
« Reply #3 on: February 25, 2013, 08:47:12 AM »
Hi stephendv1,

As you are probably aware I am not a lover of the Chinese turbines, and I have seen to many fail within a few years.

I have 4 new that I was given, 2 at 2kw with 3.2m and 3.6m blades sets, and 2 5kw plus blades, these were all scrapped by a well-known company in the UK as the failure rate was bad.

I examined about 20 odd turbines and not one of them was made like the other, it was if they all were made by outworkers and then brought to a central assembly factory where they were modified /assemble.

Bearings were a big issue, coil windings joints/connections another, and blade problems.

A couple of folk I know have replaced the blades with smaller ones, because when the wind does really blow, you need to get that turbine lowered. If not lowered then it just spins into oblivion.

I have found that the offset for the tail is insufficient, and when really blowing the tail cannot fight the blades. One guy has fitted a double sized tail and he says he has control now, but if it really blows/storm then he still lowers his turbine.

Sometime in the future I will play with the Free PMG's and Hugh Piggott'fy them on a test setup.

Pics 1 & 2 show boxes of blade sets, Pic 3, shows me collecting stuff into the MAZDA 7 seater. Very SAD to see everything getting broke up and scrapped, all those blades and about 30 turbine heads from approx. 4 Chinese manufactures.

I suggest you buy from a reputable supplier.

Or have fun and make a Hugh Piggott or Dan Bartmann, at least you will know that they can stand the winds and give you sensible outputs.

Mods, will seek cover now as the Chinese Lovers hurl abuse. :'(
Everything is possible, just give me time.

OzInverter man. Normandy France.
http://www.bryanhorology.com/renewable-energy-creation.php

3 Hugh P's 3.7m Wind T's (12 years) .. 5kW PV on 3 Trackers, (8 yrs) .. 9kW PV AC coupled to OzInverter MINI Grid, back charging AC Coupling to 48v 1300ah battery

stephendv1

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Re: Low wind chinese turbine options
« Reply #4 on: February 25, 2013, 09:03:22 AM »
Bonjour clockman,

Yes, I've read a lot of nastiness is to be had with chinese turbines, but on the other hand I've also read some good reports about the exmork turbine specifically.  I don't know much about turbines, but from the horror stories I though I could do some prevention upfront:
- replace the bearings with SKF bearings even if the ones that come with the turbine say "SKF"
- replace all bolts with stainless and nylock nuts.
- don't use any electronics from the turbine vendor, will use well known US/EU brands.
- drill a small hole in the blade tip to get rid of water?

Unfortunately I don't have the tools or the time to build one, so it'll have to be bought.  The only "quality" turbine that fits into my budget is the Futurenergy, but it only comes with a 2m rotor and costs about double that of a 3.2m chinese version.

Chris, the spec sheet for the 3.2m 2kw version is here: http://www.huayaturbine.com/te_product_a/2008-04-09/22.chtml  it looks identical to the "exmork".

ChrisOlson

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Re: Low wind chinese turbine options
« Reply #5 on: February 25, 2013, 09:29:34 AM »
Chris, the spec sheet for the 3.2m 2kw version is here: http://www.huayaturbine.com/te_product_a/2008-04-09/22.chtml  it looks identical to the "exmork".

While it does indeed look like an Exmork, I don't know if it is a true Exmork.  The Exmork turbines use the "PowerMax" S809 fiberglass blades, which are high quality blades.  And their generator heads have proven to be quite reliable.  I know several people who have them, and are quite happy with them.  I cannot really comment on this brand as I am not familiar with them.

As far as the lower wind speed performance - a typical 3.2 meter turbine will produce 250 watts @ 5.5 m/s while the 3.8 meter will typically be around 300 watts at the same wind speed.  The 3.2 meter will reach 1 kW output @ 9 m/s while the 3.8 meter will reach 1 kW output at 8 m/s.  So it's not a huge difference, but the larger rotor does produce more power at lower wind speeds.  The difference becomes more noticeable as the wind speed picks up above 9 m/s.
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Chris

SparWeb

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Re: Low wind chinese turbine options
« Reply #6 on: February 26, 2013, 12:13:32 AM »
A guy 3 miles away from me had an Exmork installed.  It lasted 9 months.



My home-built wind turbine was subjected to the same storm that day, and it's still running.
No one believes the theory except the one who developed it. Everyone believes the experiment except the one who ran it.
System spec: 135w BP multicrystalline panels, Xantrex C40, DIY 10ft (3m) diameter wind turbine, Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024
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SparWeb

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Re: Low wind chinese turbine options
« Reply #7 on: February 26, 2013, 12:16:04 AM »
...And I forgot to mention the installation difficulties, which were many.  Exmork may have improved the product by now, but it's a long list of things to solve.  The company that installed that one was so bitter about the experience that they don't do wind turbines any more.
No one believes the theory except the one who developed it. Everyone believes the experiment except the one who ran it.
System spec: 135w BP multicrystalline panels, Xantrex C40, DIY 10ft (3m) diameter wind turbine, Tri-Star TS60, 800AH x 24V AGM Battery, Xantrex SW4024
www.sparweb.ca

Windy11

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Re: Low wind chinese turbine options
« Reply #8 on: February 26, 2013, 12:31:37 AM »
 I think that there are maybe hundreds or thousands of wind companies over in China so it's hard to tell who or what you're dealing with.

I bought a 2000 watt 72 volt Chinese windmill on ebay last year for 910 bucks. I wanted to grid-tie but the voltage was too low. Anyway, to make a long story short Ron Beckers figured out a way to make it work and it's been up and running over 6 months and everything's working fine. Who knows if that will last but it furls really well and seems really solid. I'm happy!
 
Now what kind is it? I've been trying to find the name of the manufacturer ever since I got it. The warentee says "Qingdao Minjia International Trading Co., LTD". I emailed them a few times and got information but now when I go to their website, all I get is pictures of American chicks in wigs and cosmetics. I guess that trading company is out of the windmill business but  because they still have my email address, they send me info on their "new windmill products" but they don't look the same to me and don't look as well built as mine. Hard to tell.

Anyone reconize this, let me know.










« Last Edit: February 26, 2013, 12:47:06 AM by Windy11 »
Alias: Andy R.

TomT

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Re: Low wind chinese turbine options
« Reply #9 on: February 26, 2013, 10:04:13 AM »

fabricator

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Re: Low wind chinese turbine options
« Reply #10 on: February 26, 2013, 05:44:25 PM »
From all the posts on several sites I've read on the chinese turbines one thing to not expect is after purchase support.
I aint skeerd of nuthin.......Holy Crap! What was that!!!!!
11 Miles east of Lake Michigan, Ottawa County, Robinson township, (home of the defacto residential wind ban) Michigan, USA.

Royalwdg

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Re: Low wind chinese turbine options
« Reply #11 on: February 26, 2013, 11:50:30 PM »
The power vs wind speed graph on that website is way over the top.  Chris's estimates are right on the money for that size "good running" turbine.   Dave

stephendv1

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Re: Low wind chinese turbine options
« Reply #12 on: February 27, 2013, 03:37:53 AM »
Thanks all, lots of food for thought.  So perhaps the most conservative approach is to do as clockman suggests and buy a generator head that is oversized for the blades, rather than the other way around. 


clockmanFRA

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Re: Low wind chinese turbine options
« Reply #13 on: February 27, 2013, 05:10:45 AM »
Hi Stephen,
You will need to talk to "Biff" in Ireland.
 He is the chap that has played around with the Chinese bits and got one to work, although in storms he still has to lower it.
 It may sound simple just to fit smaller blades, but the consistency of the turbines are a unknown/problem.
 
Talk to Biff. Or i can give you his PM.
Everything is possible, just give me time.

OzInverter man. Normandy France.
http://www.bryanhorology.com/renewable-energy-creation.php

3 Hugh P's 3.7m Wind T's (12 years) .. 5kW PV on 3 Trackers, (8 yrs) .. 9kW PV AC coupled to OzInverter MINI Grid, back charging AC Coupling to 48v 1300ah battery

tecker

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Re: Low wind chinese turbine options
« Reply #14 on: February 28, 2013, 06:52:57 AM »
The real problem it here today gone tomorrow mechanical devices from points you can't go to . If it pays out I guess your in the black
but setting up a turbine you have parts for down the road will give you satisfaction and fit in with a long term setup .