Starting the mission
Once you accept the mission you must go over to a nearby cell tower and charge it up. You now enter a non-powered section of the Neon District. In unpowered areas Reapers are more numerous and they set up turret trucks. It is unlikely you will survive your trip to the energy substation if you run around on the ground. Thus climb up to the rooftops and use them to move about. You can use wires to your advantage but beware of turret trucks guarding the gaps.
Before going anywhere you should press select and put a way point on the location below to guide you using X. This will make the going much easier for you.
Even running around the rooftops can be harrowing so if you are running low on health locate a nearby gas-powered generator using L3. These give you almost a full charge and can be recharged by you using lightning bolt. Do not try to kill every single enemy you encounter. Beware of enemy emplacements on the rooftops as well as the Reapers' turret trucks. Don't stay hiding and shooting in one place too long because it may attract enemies to your position.
When you reach your destination look down and you will spot a manhole. Leap down, ignoring enemies, and make your way into the sewers. This time you follow the same principals as last time. Run along the path. Jump around and make your way to the charger. Once you have charged it you gain a new power: Shock Grenade. With this new move continue through the sewers and blow apart a door blocking your way. You soon arrive at a crossroads of sorts and you are stuck between three turret emplacements. Cover behind one of the electrical generators and hurl grenades. You can recharge from your cover as much as you want so don't fret. Try to get used to the Shock Grenades' curved flight. After passing the triple turrets you should find yourself at a walkway to the generator. Don't bother chucking grenades at the Kamikaze bombers just shoot them with Lightning Bolts. Shockwave them or wait for them to see you then leap off the platform back to to the gate. Recharge the generator and you are done.