Charge Controller for Wind Turbine

[Tudorbug]

We're working on a wind turbine which will ultimately be deployed from the US for use in West Africa.  Is there a "best" charge controller for use with a wind turbine?  Then, when the system is expanded to include solar power, is there a "best" charge controller that will serve both turbine and solar array or must we purchase a separate controller to serve the solar array.  Thank you!

[elt]

Personally, if I were on the receiving end, I would want one that could be serviced and repaired locally. I'd suggest that you check the West African Yellow Pages Sorry, I can't be any more specific than that.

 - Ed.

[TomW]

bug;

A hint as to the voltage, power expected, etc. would simplify answering this vague question.

Just seems it might be important information.

Tom

[Tudorbug]

Based on Ed's and Tom's notes, and we're grateful for their time.

The African country is Liberia, devastated by a decade long civil war that killed 250 people and destroyed a good deal of the national assets.  Consequently, we doubt that there is any local technical capability whatsoever.  Not only are there no yellow pages there is neither phone book nor telephone system nor electrical grid.  Off-grid is mandatory!  In a very recently installed  office solar power system (based on Evergreen ES-180 panels, an Outback VFX3048E and a 32 battery bank of S-530 Rolls Marine batteries) an Outback MX60 is used as the charge controller.

The next phase is to use a wind turbine to provide a power source for separate dormitory lighting keeping the same 230 volt, 50 cycle power.  Estimate is for 1350 watts running between 7:00 pm and 11:00 pm each day.  A Xantrex C60 is in consideration for a charge controller but we don't know if it will also service a solar array that can be installed in Phase II of the effort.  We wonder if we need two charge controllers.

Or would an Outback MX60 be a better choice and would it service the added solar panel?

And, is it true that either a Xantrex or an Outback controller would need to be wired in so that it does not allow the wind turbine to be disconnected from its load, which would happen when such a controller is used with a solar panel when the battery bank reaches full charge, allowing the blades to free wheel and perhaps destroy the turbine?  If this is a concern, we understand that the charge controller would be attached after the battery bank to system the inverter and a diversion load.  Or is this the stuff of urban legend and not necessary?

Any thoughts would be appreciated.  We're on an admittedly very steep learning curve.

David

[Tritium]

The wind turbine MUST remain loaded by being connected to the battery bank at all times. You need to use the controller that is tied to the wind systems batteries in diversion mode which will dump any extra power from the batteries to a diversion load to prevent an overcharge condition.

Thurmond

[SparWeb]

... We're on an admittedly very steep learning curve...

So am I.  That's what makes this fun!  :^)

If you already have an Outback Charge controller, then I think you want to stick with Outback for the wind power source.  I am assuming that both the solar cells and wind turbine will charge the same bank of batteries, which is configured for 48V nominal voltage.  In this case, some charge controllers will not be suitable because they are not designed for that voltage.  Luckily, you are insisting on reliable equipment, so the brands you are looking for all cater to 48V.

Every source of energy should have its own controller.  I can't see how you would safely do it otherwise.  The first MX60 already regulates the current from the solar cells.  To have a separate MX60 for the wind turbine would be a good match, provided that the turbine you select cannot over-power the MX60.  Assuming it is a match, then you will also require a "dump load", also called a "diversion".  When the batteries are full, the wind turbine's MX60 will switch from charging the batteries to heating the dump load.  This is usually a big resistor or a water heater, rated for the voltage, power, and amperage that the windmill

By having two MX60's, it will be much easier to co-ordinate the set points of the two charge controllers.  Some adjustment is always necessary to make them cooperate.  If you are considering adding further solar panels, too, then you must be prepared to get yet another charge controller, unless the first CC can handle all solar cells in the final system.

A major pitfall with two energy sources is the situation where solar energy is being dumped to the diversion load by the wind turbine's charge controller.  This can happen when the battery is full, or when the battery is not full, but the wind turbine's charge controller is improperly set.  Careful reading of the installation and operation manual of the MX60 is obviously necessary.

Good luck, and I'm looking forward to learning how the project goes!

[Tudorbug]

Let me add more in light of the additional comments that are really very, very helpful.

The equipment in place that was noted as powering an office is in a small, private secondary school on the outskirts of Monrovia, Liberia.  The school is making the long climb back from being virtually destroyed in the aforementioned civil war and is using no more than the most basic assets, in and out of the class room.  Their solar array provides basic power for lights and computers in the school's administrative office.

The hypothetical plan now in place is to build a wind turbine powered system here as a student design project in Georgia that is now and will be completely separate from the existing office power system and that would, at the minimum, deliver power for lights in a residence hall, either boys or girls or both.  First stage is to build a test bed here and run it to be sure that what we have constructed will work and will power at least an elemental battery bank even if that elemental bank is composed of no more than used car batteries.  When we have the wind turbine system up an running successfully with our minimal winds, stage two will be to add solar panels.

Once we've mastered both wind turbine and solar panels and both are delivering power, we'll look at a significant upgrade in dollar cost to get the system to a stage where it can be deployed and used in West Africa.  This is not easy to do financially but that's the plan and we believe there's a way.

The goal is to provide lighting in a place where the sun goes down very abruptly at about 7:00 pm each day and comes back up equally abruptly at about 7:00 am.  There is no lighting available in the hours of darkness.  None!  Candles and kerosene lamps are the options.

We're very grateful for the time spent in providing thoughts that support us.  We're well aware that doing so takes time.

Very kindly, David