Why Battery Bank

[Airwreck]

OK I will admit that I am a total noob to this stuff.. in the beginning of learning.

I know most folks are going to think my questions is stupid.. but if I don't ask stupid questions I won;t learn nothing.. GRIN..

Anyway I live in Barbados and in the process of building a home here.. the house in on the east coast and gets the trade winds all year round.. Simply put we have wind 24/7

At the present I am not sure of the wind speed but I think its a constant 5 to 10MPH wind.

So if I build a wind generator why would I need a battery bank???

Thanks

Eric

[zeusmorg]

 Several reasons, First off 7 mph average windspeed is not going to give you much useable energy. And even if your wind was constant, is your useage?

  The ideal is to build a wind machine that produces constantly, needs a small battery bank, and your usage is very even. Also a battery system tends to smooth out your dc current. You want your system to input  more electricity than you use, due to losses in wiring and components.

 Without a battery bank, you would have NO storage, and no capability to use more electricity than the windmill was currently outputting. You would also loose any electricity not used. You will also need some sort of dump load to use any excess you are not able to store.  

 A smaller bank has some better efficiency due to charging/discharging losses, however it also has a limited ability to store needed energy.

 Hopefully your windspeed is greater than you think. It can be measured using an aneomometer, or conversely you can get windspeed data from your local weather station, which may not be accurate for your given site.

 There are systems that do not use batteries, however these are usually direct heat schemes, or large scale storage of another type.

[Flux]

I don't know anything about Barbados, but I suspect the wind is not as constant as you think.

Assuming you are right and that it is constant then you would be able to run a SMALL load constantly. The energy in a 10 mph wind is not that great and you would need a monster of a machine to manage 250W.

If you change the load at all on a normal turbine ( assuming that constant wind)then the volts would change. You would need some form of voltage regulator and you would be ok with loads up to the small power output of the turbine.

If you want a few lights and perhaps a laptop then it may be possible.

Normally the battery acts as a an energy store so you could take a large load for a short time and then it would charge back up when you are using loads below the turbine rating.

If you never get big winds and you are prepared to use a large turbine and can deal with the voltage regulator problem ( conventional diversion controllers in general will not run without the battery although a large capacitor bank may do the trick) then it might be a possibility.

If there is any possible chance of high winds at odd times then you would need to size the regulator to handle perhaps several kW on a larger turbine or devise a clever shut down scheme.

You know your wind conditions and load requirements better than us, it may not be out of the question but the cost of a large turbine has to be considered against the cost of batteries to use a smaller one.

Flux

[Airwreck]

Thanks I admitted I was a total noob..

And everything You folks said made sense..

I will add that Mr Flux is right ..he does not know Barbados.. No negative intentions but looking at a map.. you would see that heading east from Barbados the next stop is Africa and the trade winds are constant. That's why these islands are called the windwards. GRIN.. I will admit that I was probably Way under guessing the wind speed.. It was purely a guess.. I have no idea.. and I tried to google an aneomometer But didn't come up with any vendors.. help..

yeah we do get big winds here.. Especially with tropical storms.. but that is only during hurricane season..

It looks like I have to go back and learn a lot more.. but I really want to figure this out..

Thanks again for all the help..