Rather than use electrical power to run the components of your aquaponics system, you can build a solar powered pump. Doing this will make an already sustainable installation even more so. Provided the solar panel is exposed to southerly sun, the battery for the pump will remain charged. Pumps on aquaponics systems are in almost continual operation, so the amount of energy your solar panel generates may not be enough to keep it going all the time. Having a bypass in place that lets you supplement the solar power with energy from the grid will ensure your pump is never without power.
Step 1: Build Your Aquaponics System
The first step is to build your aquaponics system so everything is ready to go. You'll need a fish tank, grow bed and flood and drain system. The pump will make the flood system work. With everything in place and just awaiting power, you can now install the solar panel.
Step 2: Mount the Solar Panel
Install a post in the ground next to the aquaponics system. If there is an existing structure that will properly hold the solar panel, you can use that. The panel must face to the south and be angled in such a way so that it receives ample sunlight during the day. Mount it high enough so it cannot be tampered with and does not get in the way of other work.
Step 3: Install Pump Controller
The pump controller will receive the energy from the solar panel and power the submersible pump. The controller should be mounted on the post underneath the solar panel for easy connection.
Step 4: Wire the Controller
The sun's energy is stored in the individual cells of the solar panel like in a battery. It is transferred to the controller as direct current energy. Because your pump runs on DC power you do not need an energy converter in the chain. Wire the solar panel to the controller. The energy thus absorbed by the sun will be transferred to the battery in the pump controller which is then used to run the pump.
Step 5: Connect the Pump
Connect the pump to the pump controller. Have a backup energy supply ready to go in case the energy harnessed by the solar panel is not enough to cover the needs of the pump. A home solar panel will produce between 15 and 20 volts while the DC pump may run on 24 volts. You can experiment with different pumps or consider adding a second panel into the array for increased power generation. Having an electrical backup in place, though, is a good idea so the aquaponics system is never without power.
With the pump connected to the solar panel by means of the controller, as solar energy is stored it is immediately transferred to the DC battery in the controller. Depending on the flood/drain cycle of the aquaponic system, your pump will be in continuous use. As long as the pump controller battery is charged, the pump will function exclusively off of solar power.