Adding a wind turbine to an existing solar setup

[Jay Arthanareeswaran]

Hello all,

I am new here and to the wind turbines. So, pardon me if the question is silly.

My set up consists of solar batteries, a pure sine-wave inverter and a retrofit solar module and a 1400W solar panels. The retrofit solar module was an add-on to my existing UPS setup and I presume it has a regular solar charge controller and has some intelligence to turn on/off the inverter as needed and use solar or grid or both (depending on conditions) to charge the battery bank. The set up is rated 24V.

Now, when I ordered the solar panels from China, I also bought a 400W small wind turbine that produces 24V AC. I would like to add this wind turbine to my existing solar setup without changing much in the setup.

I don't find any inverter in the local market that will combine both solar and wind power. And I presume it's a bad idea to simply parallel the solar and wind outputs (after a AC to DC conversion for the wind, of course)?

So, what are my options? Any help is much appreciated.

P.S:
Most of our consumption is at night. The trouble is, once the sun goes down, the controller switches to grid fully, which means, come morning, the battery is fully charged. So, to maximize the benefit, I manually cut-off the grid supply to the controller. With nights being kind of windy, I am hoping to avoid this situation as well.

[Andy Rhody]

Good questions. Not being familiar with how things work in India, I have a few questions.

Is your system "grid tied"? You spoke of a grid but also spoke of batteries.

Normally with a battery bank system, you just use the solar or wind to fill up the battery bank and then of course you need to have a controller to disconnect them when the battery bank is full.

I don't think that you need to "find an inverter to combine solar and wind" because the inverter is farther down the chain from the battery bank.

I'm sure there's some way to connect your wind generator to the mix.

[Rob Beckers]

Hi Jay,

The wind turbine should have come with a charge controller; it wouldn't be very useful if manufacturers sell a turbine for battery charging without controller. If there is one, you can simply charge the batteries from both sources, wind and solar (and by the sound of it, also from the grid).

If there is no charge controller you could use what's called a "diversion controller". The Morningstar TriStar series can be used as such. With that the wind turbine would simply connect directly to the batteries (with a rectifier), and the charge controller too is directly connected to the batteries with a load (water heater, resistors) on the other, so the diversion controller will 'divert' power from the batteries to the load to avoid overcharging those batteries.

Again though, manufacturers shouldn't offer wind turbines without a charge controller, and customers shouldn't buy any that don't come with it...

-RoB-

[Jay Arthanareeswaran]

Good questions. Not being familiar with how things work in India, I have a few questions.

Is your system "grid tied"? You spoke of a grid but also spoke of batteries.


I presume, by grid-tied, you mean the system doesn't send the excess power to the grid. If so, then no. This is not a grid-tied system.

The inverter add-on I am using basically works as a solar charge controller as well as controls the inverter. Depending on conditions, it will charge the batteries from solar, grid or simply bypass the system to let the inverter take over (when the solar produces zero output)
Hi Jay,

The wind turbine should have come with a charge controller; it wouldn't be very useful if manufacturers sell a turbine for battery charging without controller. If there is one, you can simply charge the batteries from both sources, wind and solar (and by the sound of it, also from the grid).

If there is no charge controller you could use what's called a "diversion controller". The Morningstar TriStar series can be used as such. With that the wind turbine would simply connect directly to the batteries (with a rectifier), and the charge controller too is directly connected to the batteries with a load (water heater, resistors) on the other, so the diversion controller will 'divert' power from the batteries to the load to avoid overcharging those batteries.

Again though, manufacturers shouldn't offer wind turbines without a charge controller, and customers shouldn't buy any that don't come with it...

-RoB-

Thank you both. The wind turbine did come up with a charge controller, but I opted out since I wasn't sure how the entire thing will work with my existing set-up. I can still get one from the company that sold me the wind turbine.

So, are you saying that I can connect the solar charge controller and the wind turbine's charge controller to the same battery bank? Won't there be any issues since they become productive under different conditions?

And thanks for mentioning the TriStar. I will try to understand what it does and see how I can procure one.

[Jon McGarry]

Yes you can have a wind turbine connected to lead acid /agm battery bank.
but not with a lithium battery bank, you can have both wind controller/ solar controller charging a lead acid based setup they wont interfere with each other.
does you controller have a brake function ? if not you will need something to stop the wind turbine when battery is charged because it wont stop charging while the wind is blowing !

Jon

[Rob Beckers]

Jon, why do you say you can't connect a wind turbine to a lithium-ion battery bank?

I can see an extra complication with that type of battery because they have a Battery Management System that disconnects the battery if you exceed safe limits (which should not happen to often if things are set up correctly). So, you need a wind turbine that can handle the battery "going away", the Primus AIR series for example, or some type of fail-safe where the turbine goes to dump-load in case that happens.

Can't think of a reason though why you couldn't charge lithium-ion batteries with a wind turbine...

-Rob-

[Jon McGarry]

Hi Rob,

Yes I meant without the protection required, BMS and a correct controller.
But using the controller they normally come with and direct connection will cause issues.
I am using Wind & Lifepo4 already with a Midnite classic 250 & a couple of Chinese controllers.

https://www.youtube.com/channel/UCwW9OBRok9OYV9vaZfBMniQ

Jon