Instructables

Wind turbine to charge batteries

I have a solar electric system with a battery back up for power outages.(it is also grid tie) I would like to add a wind turbine to charge the batteries in extended outages with no sun and hopefully wind ( we normally have low wind but storm outages have lots of wind). The batteries are 12 volt connected in series to produce 48 volt. Can I, should I, get a 48 volt turbine and connect direct to the batteries or some other voltage and go through the inverter like the solar panels do and if so how and what voltage turbine?.. Chris

I built a few wind turbines, and the first 3 rules are location, location, location,
If you dont have a good site, lots of wind without turbulence from buildings or trees, forget it.
there are lots of cheap turbines on ebay that come with controllers but most of them are 12 or 24 volt, you could maybe run two 24 volt turbines and have them charge 1/2 the battery pack each.
you could also build your own, there is a 48 volt kit here
http://stores.ebay.com.au/Southern-Marine-Exchange?_trksid=p4340.l2563
Ive used the blades on a couple of projects and they are awesome.
good luck with your project.
frollard1 year ago
Check to see if your charge controller/inverter has auxiliary inputs for solar/wind.

Several I've seen will work, several others wont. If you just hook the gen to the batteries you risk overcharging the batteries and damaging them (and possibly blowing up your house with H2 gas). The inverter won't care if you are using external power to charge the batteries, it will just see whatever dc voltage is fed into it. The trick comes when you try to introduce a wind battery charger/controller to prevent overcharging the batteries - if not set up right it may detect the charge coming from the grid tie as overcharge, and start trying to dump it into a dummy load, which would be bad.
papabear911 (author)  frollard1 year ago
I'll check for those connections. If it has them should I hook the turbine into that and if so what volt, 12-24-or 48 I can get a wind turbine in those voltages.
Or is it better to go direct to the batteries?
If I hook direct to the 48 volt batteries and use a charge controler and dump device would that work, keeping in mind the goal is to charge the batteries when the grid is down ans no sun.
Thanks,
Chris
The trick is to have the grid matched inverter/charger only ever try to charge the batteries up to about 75%, leaving overhead for the green power to always contribute during intermittent times.

Like I said before, the problem comes if you hook the turbine direct to batteries and the inverter sees a higher voltage and freaks out.
papabear911 (author)  frollard1 year ago
O.K all good to know but so far I still don't know what to do.

I'll look for the hook up into the inverter to accept the turbin but if it does not have it it would seem to be O.K. to hook the turbine onto the batteries as long as I have a charge controller and dump device.
If done that way would the inverter freak out?
I believe you said the invereter would not know where the batteries got their power from or if it was just already there.

Otherwise I am open to suggestion
That's the only thing I can think or suggest -- most importantly would be to check the documentation of the inverter to see exactly how the batteries can be charged and to watch out for any pitfalls.

Worst case would be the inverter charging the batteries thinking they are low, and the dump thinking they are overcharged (because of the charge voltage) -- causing the charger to go directly into the dump.
Can you run the grid-tied inverter off-grid ? Most you can't.
papabear911 (author)  steveastrouk1 year ago
I don't know, why?
Because as soon as the grid goes down your inverter locks out.