Matching Solar or Wind Turbines to Battery Banks

Need to know the amp hour capacity of the batteries. What ever you come up with divide it by number of hours of usable power you will get from what ever source you plan on providing to your charger. That will be the number of amps output from the charger you will need. I am only familiar with industrial batteries and there chargers. Most look at about a 6 hour charge time.

Thanks for your reply, I find battery info very difficult to learn as amp hours are rated and explained in so many different ways.

The batteries I am looking at are UPS12-475 12v 134 ah @ 20 hr rate 12v 475 watts/cell @ 15min rate.

Hi

I design solar (PV) and hydro-electric systems for a living. Your charge controller will be dictated by the size of your solar array, not the battery bank. It needs to be sized to handle the maximum amperage delivered by your solar array. Your wind turbine will need a diversion load controller to divert amperage in excess of your battery bank capacity eg., for heating water or air. Your solar array size is dependent on your projected loads not the size of your battery bank. If you have wind it will certainly help with power production; day-to-day reliability will determine if you can get by with a smaller array. I usually size a battery bank to meet 3-4 days of load requirements. I am happy to answer any questions you have (stupid or redundant). You need to know what your daily power consumption is (expected to be), your daily insolation (amount of good sun on a given day), expected wind, and then you can come up with a system design.

C.Deacon

People's Power

Ok...lol! I am a disabled vet. Very retired. Just bought my dream house. Want to stay very green. I need to know how many like 200 or 400w wind turbines it will take to keep say 20 deep cycle batteries charged. an will that be sufficient to run lights (the low volt) a couple tvs, a fridge, the ocasional washer load, an 2 computers? I have a plan but dont know if its right ...or if I am gettin ready to commit some serious overkill....rofl! Gimme a shout if yall dont mind thanks!!

Hi there-

You're kind of putting the cart before the horse. You need to determine how much power you'll be using and then size the system, including batteries. Are you grid connected? Your power bill will tell you your daily power consumption, and then go from there. I don't think it's too "green" to be running 2 computers and a couple of tv's... part of being electricity independent is moderating your loads or you end paying a lot of extra $$$$$ to cover superfluous appliances.

Think of your batteries as a water tank. It doesn't matter how big the tank is, it matters how much is coming in and how fast it's going out.

Good luck.

Ahh right on....I use about 2100 kwh a month an need to build a system to handle about 3/4s of that. No the home in question is not connected. I really want to keep it that way...lol! Just not sure what I need to build a bank for that kind of usage an what it would take to charge it. Thanks

Do you mean 210 kWh? 2100kWh = 70kWh/day or three times the average USA house. If it is 7kVA/day you can set up a system affordably. 70KVA is an order of magnitude more expensive.

Yeah I use about 2000 kwh a month give or take. Not really about the money just want to be self sufficient but not sure what it would take as far as battery banks and wind generators. I will not be keeping the hot water heater, stove, or central air so my usage is going to drop quite a bit. Any ideas on where to start?

Where do you live?

Well the house in question is on a mountain in west virginia with lots of clearance from trees and other obstructions but I am in bama' at the moment

If you're taking this on yourself, you'll need to do a wind survey and find out if there is enough, and how much, wind throughout the day for viable power production. Then go from there. If you have a creek, look into micro-hydro; it is the most cost-effective for independent electricity production. Beyond that is solar (photovoltaics) which run $6-$7/watt retail. On a five hour solar day (winter) you'll need a 14KVA array or $84-$98k into panels... this does not include inverters, charge controller, etc.... You're looking at a $100,000+ system to provide 70kVA/day. Again, an average US home uses 1/3 of this a day and, hence, 1/3 the cost for a system. Check homepower.com to get you started.

I have not seen what other answers you have already but it also depends on how much wind and how often the wind blows.....

I would suggest that you start small, learn a lot and expand slowly. This is especially easy if you are also a DIY man and like to make things yourself. Google what you are looking for and you will find lots of infos from people who have already made such items.

I personally only favour VAWTs as they are relatively easy to build, though not quite as efficient (then build 2). You should do well NOT to follow the "Efficiency God" as when there is no wind at all, they are perfectly equal......

Make sure you have a good way to bring it to a halt in high winds and hold it there.....safety first.

Are your batteries normal Lead Acid or Leisure batteries. I assume they are not leisure for what I am about to say.

Lead acid batteries of the size/quality you have should last almost forever if you look after them properly and never over discharge them. Look around on the web for full destails, but try NEVER to discharge them below 2.1 volts per cell......check the manufacturers recommendations first.