This quest will begin after Ghost Town ends, although you can run off to attend to other things, first, if you wish, like obtaining the Rayfield Caliburn. To start the quest going in earnest, however, you’ll need to seek out Panam in a garage near the Sunset Motel.
Talk with her and she’ll come up with a plan, for the first time making it seem like the money you paid Rogue wasn’t wasted. After you’re done scheming, hop in her vehicle and she’ll drive you to a bridge where you’ll need to engage in some practice fire with a mounted turret. Shoot the targets, then you’ll head to the power station, enduring some chatter with Johnny along the way.
When you reach the power station, Panam will elaborate more on the plan and you’ll wait for your target AV to approach. At this time Panam will drive you to your destination, near which you’ll be attacked by some combat drones. Shoot them down, then Panam will get you inside the power station. Exit the vehicle, interact with some terminals and “Overcharge” each one, then get back in the vehicle.
Panam will drive you to a cliff overlooking the area, where, after some chatter, you just need to press the button on the detonator when prompted. This will end the quest Lightning Breaks and begin Life During Wartime - the transition is almost seamless.