Backyard Aquaponics
A place to discuss aquaponics

I am setting up a system that has been sitting around partially finished
It has a 300 gallon tank, and a 4'X10' foot raft that I'm thinking can be stocked with 30 pounds of talipia or so.
It's more or less the start of a system that I'd like to eventually add on to.
However, for now getting it working is my current goal.
It's rather far away from power, and my father is stuck on using solar.
So anyways here is my bantering on the idea of solar, and I'm hoping for you guys to tell me if I am way off

I am hoping to use a Shurflo pump that uses 1.6 amps at 12 volts or 16 watts( a few hundred GPH at a 3 feet of head), along with some sort of airpump. I have used a Dual Diaphragm Air Pump from General Hydroponics, but it's 120VAC yet uses only 8 watts and will be able to substantiate what I want to keep.

Being that the airpump isn't a motor per say (since most motors want a clean sinewave?), could I use it with a cheap yet somewhat efficient square wave inverter?
Furthermore for the system I want to use a 30 watt panel with it.
(Along with some sort of economical charge controller along with some sort of battery that I have yet to figure out which brand to buy)

To make that work I was thinking of running the water pump and air pump intermediately using an arduino MCU and solid state relays that I happen to have sitting around.

So I was in the end thinking that my 16 watt pump would use 120 watt hours per 24 hour span on the lowest end of beiny on around 1/3 the time. Then the airpump would say use 10 watts with inverter losses, but would only be on for 2/3 or so the time(at any time one pump would be running).
Thus the airpump would use 100 or so watt hours a day.

Hopefully in the end I'd have 80 watt hours of surplus left if my 30 watt panel gives me 10 hours at full power, usually it's rather sunny here(although it does get rainy for days on end in some cases), and we have far more then 10 hours of light.

Anyways does my idea of what I'm hoping to do sound somewhat sound?

You're really going to struggle with this one.

The standard formula for solar power says 4 hours of rated wattage per day. This takes into account the fact that your solar panels don't track the sun, and occasionally it is cloudy.

Also that inverter will draw some power with nothing connected... Put an ammeter between it and a 12V battery to see how much.

With folding camping panels so cheap, I'd be getting one of at least 80 if not 120 watts, with a beefy 50+ amp hour battery to store the power.

If you sweeten the math on solar and power usage, you will have flat batteries.
The pump is 20w for 8 hours = 160wh
The air pump is 10w for 16 hours = 160wh

you need to generate at lease 320 watt hours a day.

Batteries are not 100% efficient either so i suggest you will need 100 watts of solar.
If you look at getting a 200w panel intended for the house roof, it will be 24v which with an MPPT charge controller, can charge a 12v battery.
The battery will need to have at least 20ah just to get you through the night.
If you want a couple of days backup incase of cloudy days, you will need 100-200ah

i tried to run a system using a 4w pump and needed 40w of solar to keep my head above water.

Thanks so much for the input!
I'll keep reading(to get more of a gasp with efficiencies),
but will go with a 100 watt panel... I think this should work :
(Is the brand good? I don't see much on it)
http://www.amazon.com/gp/product/B004OZ ... MW0P13QZ5V
With only 4 full hours a day, that definitely sets things in perspective.
(I almost want to say a properly done TEC / peltier generator could yield something usable.)

I have a 45 watt PV, 66 AH battery, with a pump that pulls .6 amps and it barely makes it through the night. But it does. If I added an air pump it wouldn't cut it.

http://www.nitto-kohki.co.jp/e/prd/d_ca ... page_num=0
http://www.hiblow-usa.com/?module=Home

cheers

I don't know where you are located JM but you may want to supplement your power supply with a small VAWT turbine. (Vertical Axis Wind Turbine). They are very efficient, easy to build from scrap materials and don't require a big pole to mount. They don't need to be "turned" into the wind and will generate power in as little as 5mph breeze. All you need is a suitable DC Magnetic single phase motor (you could also buy premade wind alternators). The easiest conversion I've seen is with a 24v 500w Electric scooter motor ($60 replacement motors available online) This can supplement the charging during the day as well as in the evenings. I'd also aim for a battery bank that will hold at least 150-300AH to ensure your system continues to operate if you hit a cloudy windless stretch. As to your airpump I have seen 12v dc air pumps on ebay and aliexpress.com You could also get a small 200w/12v dc car inverter (that would normally plug into the lighter socket) and use that to power your air pump on 110v ac. However there will be a little power loss due to the modification of dc->ac etc. The only other thing required would be a controller to stop it from turning to fast in strong winds. This simply returns the current being produced backwards to the generator effectively acting as a brake. If you understand a little about electronics you can find plans to build one for under $10

Here's the air pump I installed in my solar system:
http://www.boatstoreusa.com/outriggers- ... air-stone/

It's not huge, but appears to be adequate for my 800 litre system :-)

I'd certainly recommend going 12V all the way, ditch the inverters.

There are much better deals on eBay.

Look for folding caravan solar panels, preferably one with an MPPT controller.

I agree that you should ditch the inverters where you can. Inverters do consume current in idle, and they are NOT anywhere near 100 percent efficient at converting DC to AC. So that's something that needs to be considered when you're putting your system together.

When building the system it's a concern that your charger for the battery (and/or solar controller) is not 100% efficient either. As mentioned above, when establishing the system it's important to account for how many hours of sunlight annually it will recieve and then averaging that down to each day. That will effectively de-rate the system, a bit more realistic. If you use a sun-tracker there's less de-rating as you're increasing the the maximum power hours per day.

12VDC is a compromise in my opinion for things, the parts and pumps are more common and inexpensive .. the old auction-site specials etc. If you can get away with it, I would suggest 24v systems as there is less loss in the wiring especially in power-demand items like pumps. Remember that ohmic loss (I^2 * R) in cable is lower. You can use smaller cables for the same amount of current, so the wiring gets less expensive and easier to run.

That being said, excess capacity costs money. To reduce the excess you need to keep things up and running you need to be efficient wherever you can. Maximum Power Point Tracking is a very good idea, as is a simple suntracker if you can get one. If you can't find decent batteries for solar systems deep cycle marine batteries are a good replacement. Ordinary car batteries are not designed to be exhausted and recharged many times.. they're designed to be floated at their rated voltage and provide intermittent surge current (starting the car takes an average of 80-100A for most medium sized passenger cars). It's a common mistake to use an ordinary car battery, it may seem inexpensive up front but it will cost you down the track when they keep needing replacement.

It is far more efficient to use solar/grid power to float a 12VDC power bus that covers your fluid transfer, aeration, and controls than to have an inverter or worse a mixture.

Have you actually determined how much air you need to pump to provide your desired level of dissolved O2? If you don't have a very large system you may find that you only require a medium sized home aquarium pump and many of them run off of the common "black brick" wall transformer.. which means that with a very small amount of fiddling about you can connect them up to your 12VDC system.

Cheers!
KS

Also others have found the inverters drop out when the battery volts dip below 12v, but a 12v air pump runs all the way down. Check OBO thread for a 12v blower (heavy duty I think)

I did the sums for my system and figured a 90W panel and a 100 amp deep cycle battery would be heaps. I quickly found that a few days of overcast winter weather was all it took to bring the system to it's knees. I hooked up another 90 w panel and the system is now running great. I currently have the panels at a fairly low angle but will be building a new frame to get a better angle to the sun during the winter months.

For pumps I run two 12V bilge pumps, one for each of my grow beds, timed to run one at a time. I don't run an air pump, relying on the aeration effect of the water splashing in on return from the GBs.

The trout I ran last year did well and the Silver Perch I am running this year also seem to be going well despite the high temps we have been getting (water temp peaking at 30C)

Cheers

Shane

Hi jm,

Just an aside to all that tech talk about power supplies etc...


What volume of gravel filled GB's, or bio-filtration, have you got attached to this system?

Rule of thumb: Inverters use 1/2 your developed power while operating. Go DC.