Here in the Las Vegas area the local power company is Nevada Power.

Their main office is located at:
6226 West Sahara Avenue
Las Vegas, Nevada 89151

Hours:
Monday - Friday: 8 a.m. to 6 p.m. (Lobby Hours)
Monday - Friday: 7 a.m. to Midnight (Drive-Through)
Saturday - Sunday: 8 a.m. to 6 p.m. (Drive-Through)

Phone Numbers:
702-367-5555 - 24 Hour Customer Service
702-367-5000 - Main Number
800-331-3103 - Toll Free
702-367-5554 - En Espanol


The following link will take you to their web site.
Nevada Power