What voltage does the Windtura 750 produce?

Most of us are running two 10.8-30 volt Sun wind grid ties and have then battery tied to 24 volts. Solars will burn up.
But to answer the question open voltage or non battery tie voltage rises depending on rpm. I think high end is about 90 volts when it is free running and has no load on it.

 

Ask Josh for the article sent regarding grid tie, maybe that will help . lol

 

Please send me a copy too.

 

Murray, I have been working on the article ! I am getting there!

To answer the question, wind turbines do not produce a steady voltage like solar panels or batteries (e.g. a 12 VOLT battery). A wind turbine's voltage is a function of its rpm. The Windtura 750 is designed to hit ~25-30 volts in clean, non-turbulent 7-8 mph wind. Above 7-8 mph wind, the voltage keeps rising.

The Windtura's stator is wound so it works optimally on a 24 volt system. It can also successfully be used on a 12 volt battery bank system although it will make less power (see the power curve in the product description).

For grid tie applications, I believe Murray is running two Sun Grid Ties wired in parallel: A 10-30 volt and a 30-60 volt. Murray correct me if I am wrong.

Larry also has some Sun Grid Tie wiring diagrams posted which can be found here:

http://www.windynation.com/community/threads/wiring-methods.381/

 

One set up I have is a WN 750 & a WN 500 in parellel feeding two Sun G 500,s grid tie (wind only) 10.8-30 v. They are clamped with a 24 v battery bank and wired with a dump load to two WN 300 watt foils (total of 600 w) the 750 also has a SWEA grid tie that works @ 20-56 v. Only occassionsly does the SWEA take any load . The SWEA wil be unhooked very soon.
Both turbines are with furling mounts set to approx. 35 mp.

2nd set up is WN 500 without furling into two Sun G (wind only) 500 w grid tie . Also clamped with a 24 V battery bank and dump load to a single WN 300 watt coil.

The Sun G 250 10.8-30 is used on Larry's WM 1 kw to take advantage of low wind watts . It is also wired in parellel with a Sun G 22-60 grid tie. This combination allows Larry to take advantage of low wind watts, then as the wind increases and the volts raise both inverters share volts until the 250 reaches volt overload @ 30 V, then the Sun 1000 takes over.
Larry also has numerous posts describing his 4 turbines and how they are wired.
Both our sites are undergoing change this summer and a new adventure begins!

 

Is anybody around here using a grid tie inverter without battery clamping?

Second question: When battery clamping, are you using deep cell lead acid batteries and can they be placed inside of your house? Should I ever get a system, I'd like to put it in my basement furnace room but the thought of explosive hydrogen gas makes me nervous.

 

Andy all good questions, this info is posted in other threads but dam it is hard to find ! Yes sometimes we do grid tie without battery clamping. The only reason we are clamping is to hold down the volts and allow the inverter to produce watts without going over volt on the inverters.
If we knew what size of turbine you are using possibly some of us could offer suggestions on the use of combining inverters at different volt levels. See above where I mentioned a combination of inverters to take advantage of low wind watts and the higher mph winds. It really depends on the watt rating of your turbine and the quality of it to match a grid tie inverter or combination of.

Yes we use deep cell lead acid batteries. I also use deep cell sealed / glass matt which removes the gas build up issue.

When we are using a 24 v bank to clamp Volts we are not charging those batteries, our power production is flowing into our inverters . We do experience a very slight trickle charge into the bank during extremely high winds but to date have never experienced a battery bank overcharge. If there was a concern a charge controller could be set for your clamping bank .

 

For 24V clamping, how do you prevent that battery from getting overcharged? Does the bank tend to run closer to 28V?

 

Hello, I am using a system without battery clamping. 0ne 1kw windmax with a wind rated 10-30v 250GTI inverter and a 22-60v GTI inverter with 1kw worth of dump loads. All Sun G wind rated non UL GTI's.

Should you get a system? Depends on what your intentions are. Grid tie only, grid tie battery back up or just battery back up. Is your tubine making enough power to invest to the next level? What kind of PMA are you running?

Battery clamping is a sure fire saftery net incase the China GTI fails or as Mur discribes in the above post. There are a few good reasons why you should but again that depends on the intentions. If you want to use batteries inside buy a sealed battery not a lead acid or build a sealed case vent them or buy AGM's and keep them outside. If you do not want to use battery clamping use the dump load controller on the GTI's and walk away. It is that simple. How well will the wind rated GTI's hold up, know one know's they just came out a about a year ago.

If you are battery clamping and using 10-30v GTI then you want to clamp at 24v. if you are using a 22-60v GTI then you want to clamp at 48v. All the wind rated china GTI's i am familuar with are 10-30 or 22-60v. All batteries should be deep cycle batteries in a RE system. Only for battery clamping and no inverter hook up you may be able to get away with out a deep cycle battery. If you choose to do that or any of the suggestions we will look forward to the any information you can provide.
By the way i have seen 35v go into my 24v bank. No dammage and no charge controller. I seen over 40 MPH winds once this year so do not always get overwhelmed with facts and figures they do not always apply in the real world. Every site and system is different when you are installing your system no one can tell you a 100% you have to go on trial and error with wind. Make sure your tower is stong, your turbine is worthy and the rest i a crap shoot. Solar is a much more predictanble game to an extent.

Hope this helps

 

Last thought on the battery bank and not overcharging them,,,, Larry used new batteries and their full charge potential exceeds mine!
For my wet cell batteries I use recycled lift truck 6 volt batteries. There is a reason they call them recycled , they are well used and I have found their full charge as a bank using a grid fed charger usually top out around 25.5-26.5
After removing the charge they will settle to approx 24.4-24.7 volts, and that was using a constant controlled charge, which the wind never is. In winds recorded at 38 mph I have never yet seen my bank trickle charge past the 24.7 volt using my recycled batteries.
The mur
One of the best comments I have read so far is from Larry when he said, " so do not always get overwhelmed with facts and figures they do not always apply in the real world "

Best bet is to use information out there as a guide and not an absolute, everyones conditions, turbines, locations , uses maybe different so with wind there is usually a lot of experimenting and tweaking to be done.

 

Thanks Mur great follow up.

 

It might be wise to put a 2nd diode in parallel to the battery because if the first one dies then the GTIs pop.

 

I used 2 in parallel because with one it was getting hot in higher wind. I used two 40 amp post type for extra measures. I know over kill.

 

Tom interesting thought. What I see happening if there is a diode failure would be because the Sun G for wind grid tie you have two different models to choose from, each have a volt overload and on has a dump load diversion. In both cases the battery clamping works to hold down the high voltage so if the diode failed and the voltage rises beyond what the MPPT in the inverter can handle the unit will go into a volt overload and sit idle until the turbine rpm slows too lower volts. The dump load option during a diode failure, when the volts increase beyond the rated voltage would direct that power to your choce of load which might be coils such as WN 300 w coils in parellel or to a 2ndary bank which may already ave it's own charge controller. ( this would also involve some more creative wiring with diodes which I will not bother to go into)

BUT where I think your comments really help is in the case of a diode failure and it does happen what can happen to your 24 v battery bank if you are using a SunG 10.8-30 v. Without the diode the bank would back feed to the inverter until it dropped below the 10.8 v. Start range ! If that happened we might be saying the lords prayer over that battery bank !

There are so many ( but what if's) that I do not know when to draw the line on micro managing our projects so badly that we have taken them to the extreme ! But for the cost of some wire and a simple diode I will be looking at this safe guard for my bank. Thanks

 

For my battery clamping bank. I went out and bought 2 garden tractor batteries just for clamping. I switch it to the bigger bank to charge the batteries up every once in a while. Last time was 3 months ago. Battery voltage stands at 12.25 volts same place it was after 3 days of not putting juice into it. That is why I went grid tie. I would have a good day and in 1 or 2 days it dropped back to 12.25 volts. That is alot of power lost all the time. So with the grid tie we pump it in the grid and take it back out when we need it.

 

Those sealed agm(7.5amp hour) sold for deer blind cameras work very well W/ diode above.Very little lose in effiecency and let the charge controller flow nicely in high winds and over volts...I just added a 6 volt one of these to run a 30 volt system so all of my electric produced goes into the grid. You lose very little to batteries.You would be suprised just how much more watts you make if you unhook the batteries in good wind and see how much more turns into real world energy produced..
I set my charge controler from coleman at 29 and have to have extreme wind to see it to ever turn ,,I am feeding into 3 sun-g 600's 22-60..Once there are more turbines up this will happen easier but I will also add to that 30v battery bank.. VERY HAPPY WITH THIS SETUP....

 

Like I said before there was a bump up in speed of the turbine and wattage in higher winds at about 30-36 volts. I just do not have the wind around here to run it that way.

 

So get another one up even if its just a delco and run the dc in series to always be in the higher volts..I cant do that because I do get hella wind alot and dont have a charge controller to be able to run a 60v battery bank..Dont think they even make them..

You could fly two turbines or a panel with your turbine to run a 48 volt system and charge controller tom..That would make sure you optimize the turbine being able to put whatever it makes into electric so you arent clamping the speed down to 10v..You should unhook it when its getting 10 mph winds and let it freewheel so you can see how fast it would get going before the 22v gt's would start to put the load on it..

 

I really dont like those low volt gt's for our style turbines..We are running such a small footprint that we need to let it get spinning enough to capture all the wind..the large ones spin so slow for safety reasons but in a efficiency view they are not capturing even half the power they could put out..Thats why they whistle from the air pressure off the blade edge...