Sacrifical anode

Our first attempt at converting a natural gas tank to an electrically powered water heater involved removing the sacrificial anode used to prevent corrosion inside the tank due to the galvanic reactions. These anodes are typically made out of a more electrochemical metal than the type used for the walls of the tank.

Sacrificial Anode

To get the anode out, we found a socket at our local hardware store that fit and used an air impact wrench. Once the bolt was removed, we put the water heater upside down on a forklift and let gravity do the work.

Natural Gas water heater upside down on fork lift

After removing the anode, we tried to design a device that could be inserted through the top port and serve the function of a sacrificial anode and a heating element.

Top of Natural Gas Tank

In the figure above, the anode port is the top left most knob. We started thinking of ways to incorporate both the sacrificial anode and the heating element in one device. The approach we focused on used a copper pipe coated in aluminum (the same material used as the sacrificial anode) that extended to the bottom of the natural gas tank. We would then attach a heating element at the bottom of this pipe and create a feed through for the wiring needed to connect the element with an external thermostat and the solar panels.

Design 1.jpg
Design 1

After designing a few ideas, we ran into problems regarding sealing the wires used to power the element, fastening the element to the anode, and pairing a thermostat with the submerged element. Finally, we scratched this idea and returned to the drawing board in an attempt to utilize the drainage pipe located on the side of the tank towards the bottom.

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