Backyard Aquaponics
A place to discuss aquaponics

I searched for this but didn't look hard. So what I was thinking just for a backup aerator if the power goes out. So if you see my system you may know I plan on having a pump in a sump tank so it can't drain my system should something happen. So what I was thinking should the power go out having a turbine connected to the exit flow from the tank turning an alternator connected to a car battery would be a nice backup. The drop from the pipe should be around 5 feet. But I've been looking around and most basic ones are 1/2 inch hose type setups mine is going to be a (2 inch PVC type connection). Just wondering if anyone has done this or did a bit of research on the idea. I was thinking that should power failure happen the aerator would be connected to the battery and would cover for a few hours, and I was thinking if I didn't run my pump 24/7 this could be left on to aerate the tank during nights. Also since there is circulation of water might as well use that energy. I don't know how cost effective it would be compared to solar but I think it would be better as cloudy days or lack of sun could affect battery charging. Opinions?

The topic was discussed here
viewtopic.php?f=31&t=6455&hilit=turbine&start=45
and in other threads.
It's doable, but probably not with a standard car alternator, you'd never get it to spin fast enough unless you had a huge system linked to a water wheel and geared it up.

Yeah I looked at that thread and it seemed really unfocused on the topic I'm looking at, I see it mentioned but not much. What if your goal was just to power something like this? I mean it's not requiring a whole lot of electricity.

+1

One of the problems with creating energy from a stored reservoir is that each iteration of the
"store to generation" includes losses. This means that every time you pump water up to your hydro electric generating dam, it costs slightly more power to pump up the water than you get out of the generator on the way back down.

The result is, if you try to power your system off the stored energy in your upper tank, you end up with around 45 seconds of usable energy, and you can only pump 17 seconds of water back to the top.

On the next go, you run out of pumping minutes.

If you can solve this problem with the structure of the universe, you will become so wealthy that, like superman, you will have no need for actual money because every time you need a beigel, someone will be more than happy to give you one for free

I just realised something.

The "conservation of energies" means that Superman would need an alarming number of beigels.

I'm no longer convinced that Superman is a viable entity!

*Raises slapping hand*

Take it back BW....

take it back now !

Hey BW,

If you re-read the OP you will find he only wants to build a mini hydro electric to charge a car battery for a back up airpump, not to pump water back to the top tank, this is not one of those "creating energy out of thin air" posts that we get so often.

Markymark

The idea is doable (?sic?) but it is a lot of mucking around for something that just charges a battery, it would be is easier to just use a mains powered battery charger, electricity isnt that expensive that it would be worth your while putting together your generator. In saying that it sounds like a great little project if you are one of those that like to experient and build things, so go for it and have fun in the process

Opps sorry Markymark

My bad

thanks Simo

I was scratching my head after reading the replies lol. You are probably right, it'd be much more expensive compared to what you mentioned. I just thought it was an interesting way to give satisfaction to know one solved a problem off grid. My tank is gonna be around 50 feet from my house and running a power line from my house was what I was avoiding. I'm trying to figure out how to set it up where it's convenient without hiring an electrician etc. My tank is gonna be in the back of my yard so I'm kinda thinking of running an an extension cord for now but gotta think of something else more reliable a bit later. So I'm always nervous of the what if someone unplugs it and "oh shit" stuff happens. But either way the battery backup is going to happen for at least air. Also if I wanna shut the system down for the night the aerator would be on either way. Was thinking of using a deep cycle marine battery. One of those huge ones for backup.

Another thing to consider is that if your system was stocked to the max (and I think most people try to cram as many fish in as possible )
The energy taken out of the falling water would need to be put back in via some mechanical means to make up for the lost aeration of the splashing water which adds a lot of DO.

I was thinking of making a generic power takeoff like a tractor might have. I was thinking from a paddle wheel running off my return water. I wasn't sure what I was going to do with it, but it's always handy to have some motive force just kicking around

One potential use was to run a conveyor belt with a bottle of feed sitting over it. Sitting so that the belt stopped all but a tiny amount of feed from exiting the bottle.

Gear the paddle wheel down enough, and you could slowly dose your fish with feed.

It would be largely pointless, but I love pointless

Sorry again. People like me who don't read posts properly, then reply to them drive me nuts.

Or the action of the disintegration of the water stream interrupted by the turbine might add to the oxygenation

Either way, it's almost certain to be one or the other

I'm gonna be running a 4200 gph pump for a 2200 gallon tank, I'm still working on the math for the tank setup but I'll probably moving at least 2800 gph with a 6 foot lift. Now that I look at things it'll be running 24/7 so shouldn't have oxygen issues as I am gonna be stocking to gb capabilities which equate to about 127 lbs of fish. I'm going to be adding more GB later but for now that's what I'm at.