off grid aquaponics system help.

It is not advisable to enlarge an old solar battery system because you should never mix old batteries with new ones.

I would suggest you build the first system to handle a single pump (35watt x 24 hours = 840 wh) and size it for 1000 watt hours used daily. Then when you are ready to install the other 3 pumps build a second system 3 times the size of the first or build 4 systems all the same size and dedicate each to it's own pump.

Converting from a 12volt system to a 24volt system means throwing away all of the 12volt inverters and possibly the battery charge controllers. There is no really efficient way to do this.

I'm not sure why you want to build an off grid system but after the dust settles, a system(s) that provides 4kWh a day will be kind of expensive as compared to using power from the utility.

You can't. Just simply plan and built the full-up system. And plan what to do when you have 3 cloudy days, and the batteries are dead. Do you have a generator for recharging ? Do you carry batteries to the house and plug into a charger ?

If it's at all possible to get a trench out to the aquaponics and get utility power to it, that's going to be the best thing, IMHO.

(dang, I need to get a job selling solar gear and then I can change my tune and make $$)

I am leaning to a 24v system now. The pump is not running all day. It kicks on and off. I will shut it off at night so it won't be that much power usage. 250 watt solar pannel/ pump on the diagram above seem to be sufficient when they turn the pumps off at night. We have a lot of sunshine here in OK.

What type and how many batteries will you be using?

4, 6V-200Ah golf cart batteries wired in series for 24V, will store 4800wh, with 50% avaib for deep cycling. (a normal deep cycle battery is expected to cycle only about 30% down, for long life. Your daily power usage is a little under 4Kw, so a simple, cheap ($400, 4 golf cart battery) bank won't last a year under those tough conditions. Double the batteries to 48V, and you would be in good shape.

To recharge 4Kwh depleted batteries, you need to harvest almost 8Kwh, winter sun being barely 4 hours in most of USA, you will need a 2Kw PV array. And you'll have extra power in the summer.

You can "game" it, and try the math for only 50% run time at night and save some power there, smaller battery, smaller array, but the risk to the plants.....? And do you ever get cloudy weather ? PV puts out about 10% in cloud cover, so 2 days and your batteries need a charge from ?? ?? a generator ? extension cord?


Discharge charts here https://www.google.com/search?q=batt...h+of+discharge

If I have a 35 watt pump running around 6 hours a day(probably less) that would = about 210 wh right? Would a 260wp panel not work for 210wh?

I was planning on using the golf cart batteries listed in the diagram above. That was my reason to have it 12v at first and then adjust to 24 volt later on. basically 2 batteries per pump.

Golf cart batteries come in different voltages and Ah ratings. You can use 4 x 6v in series for a 24volt system or 8 x 6v ( 2 parallel of 4 in series like in that diagram) for a 24volt system at double the Ah rating of the first. But before you purchase any batteries you first determine what your daily watt hour usage will be and then size the battery system around that figure.

A solar battery system (regardless of the voltage) is not like Lego's. You can't expand it by adding more blocks (batteries). You either build a system at the voltage and Ah rating to supply your immediate needs and when you want to make the system bigger because your watt hour needs increase you need to start from scratch with batteries all the same age and type.

Or you can build the battery system to meet 100% of your future expected watt hour usage (4 pumps) but just run 1 pump and add the rest. Of course this way you may kill off your batteries before you have added the 4th pump which would be a waste.

You also mentioned using 2 batteries per pump but unless you have 4 systems with 2 batteries each you can't just add 2 more batteries to the first 2 when you add the second pump. Again this is not like Legos.

That's about a 4500.00 system just so that you're aware. Maybe could be done for 4K without racking for the panels but don't forget to factor in the fact that you're going to have to pay a core charge per unit on your first set of batteries and figure in the cost of the wiring/fuses/labels etc. The little things will nickel and dime you to death. Don't forget to factor in the cost of a generator and a charger because the 1000W of panels won't be enough to finish the EQ cycle.

I've got a system very close to what is in the diagram so I'm very familiar with what the costs will be.

I'd eliminate the wind turbine and reconfigure the battery bank to a single string 48V bank. Use the saved money from the turbine to buy a gen and charger.

The system Zack has is not running on a 35w pump, per lets just say a string or 1/4 of the system. A 35w pump will not lift to the level you need. Head presser is a factor, and 35w will only push 7.5 at best. The system he has runs for 12 on and 12 off but it also runs air pumps for the time it is not flowing water.

He is running about 250 watts per hour. For 12 an 12. On vs. off.

To break it down 3kw for 12 hours, then what you need to factor in the air pumps for 12 hours. My system runs 4 35w pumps and 4 17w pumps to get the head I need. It also has 4 air pumps running when I don't have the power that I want to push to the system.

Without the air pumps the system is dead in days. Your looking at close to 3kw per day without the air pumps and that's at 12 or only half a day 12 on 12 off. To run the system right you are looking at 6kw, and if you want to run a 1/4 of it as a test you are still looking at about 2.5kw to do it right.

Maybe 2kw to do an on off system. but you take the chance of killing the system.