Backyard Aquaponics
A place to discuss aquaponics

Since starting to look at aquaponics I have had two major ideas of things that could be done to improve self sufficiency. One is under wraps lol the other is one I've been throwing around and searching for ideas on for a while is about mini hydroelectric systems.

Picture this...

A pump, attached to mains electricity (to start with), in your tank is passed through a constrictor to increase the flow rate. It comes out in a jet and strikes a pelton wheel water turbine. This also aerates the water considerably as it falls back into the tank. The pelton wheel water turbine is attached to a Fischer and Paykel SmartDrive (which generates a huge power punch) and the force of the water turns the generator which in turn charges a bank or two of 12V or 24V deep cycle batteries. These deep cycle batteries often store enough power to provide electricity for multiple homes. After a while running off the mains power the battery bank would be fully charged. The battery bank is connected to an inverter to take the 12V or 24V output and boost it to 240V AC current. The pump is then disconnected from the mains supply and into the supply released by the inverter so it draws from the battery bank and becomes a self sustaining system. The battery bank supplies enough power to run the pump and your whole house spelling an end to electricity bills and power failure woes (I'd be keeping a back up pump or three handy I think and maybe a reserve battery bank... dunno) - excess power can be fed back into the grid for $$$ or credit - battery banks cost around $2000-$4000 for a house, and the fischer and paykel generator kit and pelton wheel can be purchased online here: http://www.ecoinnovation.co.nz/product_detail.php?id=81 for $2200 NZ ! Not sure about the inverter.

I can dream anyway

Interesting idea OzV, but I think you'll find that there are too many loses in the system due to friction in pipework, heat losses in the inverter, heat and friction losses in the pumps etc.... You can make some power back by converting some of the energy of the water movement back into electricity, but you will always be using way more power than what you can make due to the losses described above....

On the other hand, if you had a stream nearby, you can produce yourself some serious power, and never need to rely on the grid. Even if you have very little fall over your property and it's really not suitable for a pelton wheel, there are many other methods of producing power using those fantastic washing machine motors.... I was almost happy when my Fisher and Paykel washing machine broke down, however, after checking out the wiring mods that have to be done to the motor to make it work as an efficient motor, I decided to give it a miss. I gave it to an electrician mate who was going to play with it and make the mods himself.

Plenty of prize money available for making a perpetual motion system. That's because it defies the laws of physics.

The pump is inefficient and doesn't convert all electrical energy into kinetic water flow, the wheel/VSD/generator doesn't convert all the kinetic into electrical, plus battery storage loss and invertor loss. Every time you convert energy from one form to another you loose some. It's only a matter of time before the losses will make it stop.

You are better off charging batteries off mains, and then powering the pump off batteries/inverter when the mains goes off.