While originally intended to power cities, the Japanese military had come up with an in-genius plan to deter Godzilla away from Tokyo. Sine projectiles could not penetrate the monster's flesh why not shock it with electricity? With in record time they had built power lines along Tokyo's shoreline, using them as a sort of electric fence.
The results were mixed. For something that wasn't meant to be weaponized, the lines did managed to hurt the beast, the only other thing to have harmed the original Godzilla in 1954 was the Oxygen Destroyer. However it was neither enough to kill the monster or turn it around, instead it hurt the creature enough to use his Atomic Breath in a rage of fit on the entire city, something he had not done on his first short night in the city before and had up until that point only used his energy weapon on ships out in the sea.
Still, the fact it made the monster use a hidden ability meant they were on the right track, as in 1962 the same idea was done before but with more power, which was enough to actually deter the second Godzilla. These would encourage power monster killing weapons later on the series, with the Showa series having the Artificial Lightning Generator and Giant Electrodes and the Heisei series having the Thunder Control system, all of which have proven effective despite their flaws.
The one downside is monsters who feed off of electricity would be empowered and even attracted to such weapons, so it is not a one size fits all solution.
But overall a cool idea and clever solution for when bullets, bombs and rockets fail to get through a monsters thick skin.
