Black-out Boomer Achievement/Trophy
The "Black-out Boomer
" achievement/trophy is earned by destroying a generator with C4. This can be achieved once you unlock the C4 skill from your skill tree which can be done fairly early into the game as I was only level 6.
There is an area on the eastern edge of "Itacua Providence" named F.O.B. Armadillo that is home to the Unidad Forces. Inside this base near the front gate there is a generator behind a locked fence. Shoot the lock off the gate, place the C4 and after the explosion you'll get your reward.
If you have any questions feel free to ask!