Do you have any scientific data to prove that? E-Cat's don't shock unless they have to generally.
Malapterus Electricus can get about 3 feet and is the most common in the pet trade. They grow pretty slow like 1" a month and don't need a huge tank because they don't really swim around all that much. You could get away with 1 E-cat in a 180 gallon for a long time like years. Search some of my old posts for more info on E-Cat's, I've kept them up to around 12" in the past and kept them successfully with synodontis catfish species
You're right, this is only personal experience- not science. Ours ate a lot.
Electrical organs are modified muscles, so they're going to burn fuel all the time in sensing the surroundings, like your brain does. But yes, this statement was speculation. I know a 6" cat was able to heat up its transport pail (5gal) by an incredible amount (uncomfortably noticeable, >10 or 15C) over less than an hour. I'd do the jules generated on that, but am not sure it'd be valuable beyond "plenty"
A