All professions have 480 health, 20 energy and 2 regen at level 20.
Standard armour gives Rangers +5 energy, +1 regen, and gives casters (Elementalists, Mesmers, Monks and Necromancers) +10 energy and +2 regen.
Mesmers, Monks, Necromancers, Rangers and Warriors can get additional bonus energy from special armour options (Enchanters, Acsetics, Scar Patterns, Druids and Gladiators respectively) typically +7, but +8 is possible for the Monks and Warriors who also have a head piece in this armour set.
Elementalists may boost their energy via the primary Elementalist only attribute Energy Storage, at 3 energy per rank.
All classes may then use equipment (foci, wands, staffs and on rare occassions melee weapons) to further boost this.
My ELE has 120 ENERGY but.....I only play with 111 ENERGY at the most BECAUSE I lose 75 health for the extra 9 energy. Besides what would you rather have 75 health or 9 energy?