Author Topic: Wind turbine loading  (Read 821 times)

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Offline TurboMiles

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Wind turbine loading
« on: January 11, 2017, 06:55:08 AM »
I have a very simple system that may not be very good and I'm curious how you control/load your turbine.  Do you charge batteries or are you grid tied? 
I've been reading about the classic and the ABB grid tie.  I like both and the classic is appealing but a battery bank can get very expensive.
Maybe there are other options out there that I don't know about. 
Thanks

Offline rossw

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Re: Wind turbine loading
« Reply #1 on: January 11, 2017, 01:58:30 PM »
With photovoltaic cells, you can use only as much as you want at any given moment and the surplus is just forgone. No ill effects.

Hydro and wind turbines however require a suitable load to control their speed. Without the load, they will simply speed up and up until they basically fly apart (or some other speed control kicks in - like a furling tail, or tap on the water line).

Batteries make a convenient way to capture power for later use - but if they are (or become) fully charged, or if they are not of sufficient capacity to take the full output of the turbine, then additional loads are required. So-called "opportunity loads" are often used - like large heating elements in hot-water units. If your water is already too hot, you'll need other places to use that power (or a way to shut down the turbine). Many people (myself included) have a large resistor "dump load" that is a last resort that the turbine controller can use to control the turbine.

Offline TurboMiles

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Re: Wind turbine loading
« Reply #2 on: January 11, 2017, 02:06:52 PM »
I am asking what do you use to convert wind turbine power into something you can use before the dump load is required.  I totally understand how a turbine works and it must remain loaded.  Are you grid tied and if so what device do you use.  Or do you charge batteries and if so what device do you use and what inverter do you use to get the power back out if the batteries. 

Offline rossw

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Re: Wind turbine loading
« Reply #3 on: January 11, 2017, 03:08:42 PM »
I am asking what do you use to convert wind turbine power into something you can use before the dump load is required.  I totally understand how a turbine works and it must remain loaded.  Are you grid tied and if so what device do you use.  Or do you charge batteries and if so what device do you use and what inverter do you use to get the power back out if the batteries.

Ahh, my bad.
No, I'm completely off-grid and have been for errr... 13 years I think.
I have what amounts to a large 3-phase bridge rectifier after my turbine, along with some voltage comparators that kick in part or all of my dumpload if the battery voltage gets too high. That rectified output goes through a current shunt and straight to my batteries.

In anything short of a howling gale, my turbine can't make much more than my base-load, so the over-voltage stuff has hardly ever triggered.

Offline TurboMiles

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Re: Wind turbine loading
« Reply #4 on: January 11, 2017, 07:06:27 PM »
So in your situation the battery is the load for the turbine.....How large is your battery bank?

Offline rossw

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Re: Wind turbine loading
« Reply #5 on: January 11, 2017, 07:22:25 PM »
So in your situation the battery is the load for the turbine.....How large is your battery bank?

The equivalent of about 45 kWh lead acid.

Offline TurboMiles

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Re: Wind turbine loading
« Reply #6 on: January 19, 2017, 06:48:41 AM »
I'm thinking about buying 4 tesla model s modules.  Each is 6kw and little maintenance, can be discharged 80%, but $5k is hard to part with.

Offline rossw

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Re: Wind turbine loading
« Reply #7 on: January 19, 2017, 01:40:09 PM »
I'm thinking about buying 4 tesla model s modules.  Each is 6kw and little maintenance, can be discharged 80%, but $5k is hard to part with.

I'm not sure I see the attraction of tesla modules. $5K for 6kWh ??
I've just bought 112 x 200AH 3.2V cells. For comparative purposes, $5K gets 16kWh of LFP.

Offline frackers

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Re: Wind turbine loading
« Reply #8 on: January 19, 2017, 03:37:33 PM »
I've just bought 112 x 200AH 3.2V cells. For comparative purposes, $5K gets 16kWh of LFP.
Wow - that's an attractive price!! $44 each? Where do you get them from...
Robin Down Under (or are you Up Over!)

Offline rossw

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Re: Wind turbine loading
« Reply #9 on: January 19, 2017, 03:44:33 PM »
Wow - that's an attractive price!! Where do you get them from...

The manufacturer. (And then import them myself to stave off multiple levels of on-selling each adding their 30% margin!)

Offline frackers

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Re: Wind turbine loading
« Reply #10 on: January 19, 2017, 03:53:36 PM »
Ah - thought you meant 112 for $5k !! So you have over 100kwhr in LiFePo4 ? Sounds like a container load ;)
Robin Down Under (or are you Up Over!)

Offline rossw

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Re: Wind turbine loading
« Reply #11 on: January 19, 2017, 04:08:05 PM »
Ah - thought you meant 112 for $5k !!

I wish!

Quote
So you have over 100kwhr in LiFePo4 ? Sounds like a container load ;)

No, nowhere near that. And it works out at a little over 70 kWh
This isn't all for me. Half for me, half for another chap. We're splitting the consignment which reduces our (individual) importation costs.

Offline TurboMiles

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Re: Wind turbine loading
« Reply #12 on: January 22, 2017, 09:13:50 AM »
Not exactly sure why (maybe water)but my blades have become unbalanced.  I might have to get some fiberglass blades if keeping the wood blades balanced will be an issue.

Offline niall

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Re: Wind turbine loading
« Reply #13 on: January 25, 2017, 04:19:45 PM »
the balance shouldnt change that much , ..or so quickly with wood blades turbomiles ...some can be run with little coating at all
maybe something is beginning to loosen at the hub ........i,ve left bearing nuts unlocked and things went south fast .......hard to know

if it doesent " feel right " maybe take it down and check..................but thats easy for me to say

the first run usually brings out the gremlins.....

Offline Solarnewbee

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Re: Wind turbine loading
« Reply #14 on: February 01, 2017, 03:10:26 PM »
Hey guys,

Here's a Dump load I built for a dual pmg. 100w wire wound resistors 1ohm each wired in parallel to achieve 1/2ohms to break when batteries (Pete helped design this delta wiring method)

SN
SN

Any day above ground is a day for potential mishaps