Backyard Aquaponics
A place to discuss aquaponics

Hi everyone. I am brand new at all of this, so I've got a lot to learn here.
I want to set up an IBC system in my shed, and I had the idea to run the whole thing on solar panels. It seemed to me that I should run the whole thing on 12V DC so I wouldn't need to buy an inverter. Trouble is, I can't seem to find any equipment that runs on DC. Is anyone doing this already who can point me in the right direction? Or does this not make any sense? Anything helps. Thanks.

Check marine stores / camping stores / internet.... there's heaps out there!

Check out my solar system in my signature.

Yes 12V everything is the way to go, be sure to use a brushless pump.

IMO 24V would be better than 12V, with smaller diameter cable requirement and/or lower cable losses, plus the voltage better suits new low priced "24V" solar panels (actual maximum power delivered at about 36V is typical) - otherwise too much energy is wasted with inexpensive PWM charge regulators. Of course if you dont mind forking out the cash, a decent MPPT charge controller will allow a wide range of panel voltages to be used with a 12V battery system. It really comes down to how much you want to spend.

I'm planning to make my backup pump with a surplus 100W 24V PM brushless motor (~$20 ) and a washing machine pump ($free). I haven't hooked the various bits up to see what sort of flow it will deliver yet though...

we have an off the grid 12V system running here, was running great till today we found that some bugger has played with it, tried to pull the timer out to have a look and ripped the cables off the back, blowing the fuse... We were wondering why the system was going green and the plants were drooping.. The solar box here will now be locked up...

Hey EB, can't believe someone would vandalise the system like that. So wrong.

That's the Aussie way.
If you cant afford it, scope it out to see if you can copy it.
If you cant copy it, destroy it to teach the smart ass a lesson for building it in the first place

In my defence it WAS shiny!*




*Not really. I haven't been to WA for 20 years

check out this place...their localish, st.thomas area. their the closest place i've found so far for solar power products for a decent price. much better quality as well than anything you can find a home depot, etc.

some are also canadian made!

http://www.theresourcestore.ca/categories.php?cat=17

solar has been something i've been looking into using however for me the problem has been the winter and how to power a water heater at a cheapish price...

Heating is also my biggest barrier right now. If I even had an idea of how much power its going to take, at least I can plan for it. Do you have a system going already? Do you have an idea how much it costs to heat it?

It's probably already occurred to everyone, but when it comes to heating your system, the growbeds act as super efficient heat exchange devices, and will always try to make your water match the surrounding ambient temperature and heat the rest of the world at your expense..

The world is really big.

I forgot this fact when I tried to heat my first little system. I ran a 300 watt aquarium heater in a single blue barrel system, and it was on most of the time through winter.

I live in adelaide, south australia... think Mediterranean climate with winters of perhaps 8c-18c max daytime and maybe an average overnight low of 4c ((Guessing) adelaide foothills)

The system was 100L FT and 100L growbed, and the aquarium heater was on almost all the time to keep it at 18c. From memory it ran flood and drain once every 45 minutes or so.

A greenhouse worked much better.

Currently, I don't have a system up and running...I'm in the planning staging just like yourself. I have my system designed up until this heating issue. From what I've worked out as "very rough" calculations it was gonna cost me in the range of $3000 for enough solar panels to heat 1000L tank running 24/7.
The heater is a power hog! Using conventional hydro it worked out to being about $580/mth in hydro bills by itself! That wasn't factoring in any kind of shelter, insulation, etc. So that would be the worst case scenerio...

Without factoring the heating into the equation roughly 1 230W solar panel was more than enough to power the pumps, etc. I have yet to find any links on the net for help with calculating how much a greenhouse would cut back on costs as well as any calculations pertaining to how much heat will be stored in the water, etc.

The heating situation at the this point has blown my budget allowances.

Attempting to successfully heat a system with PV panels is likely to be extremely expensive, evacuated tubes will give a lot more heat for your money. You will need quite a bit of hot water storage capacity too. PV panels are only about 15% efficient, evacuated tubes are 4-5 times more efficient.

Totally possible..

My single IBC off-grid setup:

1 x 1000 lph 12/24 volt DC pump, $60
1 x 40 watt monocrystalline solar panel, off ebay $70
1 x 10 amp solar charge, off ebay $20
1 x 12 volt timer, $20
1 x 12 volt, 35 amp hour deep cycle battery, off ebay $90
1 x old esky to create waterproof housing for electrics, free off side of the road


The 12 volt timer was the most difficult component to source. Bought mine from Jaycar in kit form and had to solder up the circuit.

I'm running it on a 30 min on / 30 min off flood and drain cycle, 24/7. I think I possibly oversized the battery and panel as it never seems to drop below 80% capacity, which will guarantee a long battery life.

This photo is when I first planted it out, before it had cycled:




Going well so far

Running pumps, timers, etc is easy, but heating from PV panels- not unless you want to spend a lot- and Ontario is a lot colder than Cowra in winter

How does your battery go at the end of an overcast winter week?