It is highly unlikely. Two main reasons are:
- Source: Wikipedia. It is evident that the eel produces only 860 watts of electricity for a mere 0.2 milliseconds. This is too little time. The power sources must be reliable and able to last for a long period of time. Eels cannot do this. Eels need to recharge after each shock. Giving such a shock takes a lot of energy out of the eel. Imagine how difficult it would be for an eel not to produce voltage continuously.
- Even if that wasn’t enough, animal cruelty would end the problem in its tracks. They would need to be raised in order to become a reliable source of energy. It would be an ecological and moral disaster.