I started xplosive/energy char and wondering where is good place to farm energy weapons,energy ammo and explosives. Expect Brotherhood of Steel bunker and Van Graffs shop. (I dont wanna kill those cas they dont respawn.)

Guns and melee weapons are evrywhere,but what about explosives and energy weps? I believe there must be places with alot enemys who have this.

Boomers for Explosives. Repconn HQ has some energy weapons and ammo, plus the unique Plasma Rifle.

Lots of Fiends in the ruins southwest of The Strip carry energy weapons. And they do respawn.

Hooverdam Quartermaster.

Cliff Briscoe in novac usually has dynamite, mines, grenades, C4 and detonators.

The Khans' Armorer and Quartermaster Brandon have massive quantities of EW ammo and many of the weapons, however for explosives you want the Gun Runners' Vendortron and (if his inventory doesn't 'lock up' on you, as it is wont to do) the Boomers' Munitions Chief (he's in the Mess Hall hangar along the wall). The QM's shop has to be unlocked before he will sell to you, though.

Make nice with the BoS and you can get free EW ammo roughly daily provided you have completed Still in the Dark, from 1-3 of the basic types will be present in decent amounts in a crate on the first level landing just to the side of the door.

i just have one thing to add:

after finishing the BoS quests, you don't have to wait every 24 hours to go back. simply walk out the front door (with loading screen) go back in, and more ammo will be in the footlocker. abuse as desired.

I've found that doing that doesn't always work, however I don't try it all that often either. Never really needed to when Jury Rigging lets me repair 5K-cap weapons for next to nothing and sell them for a crapton of ammo.