Retailers Include: AEP Energy , APG&E Energy Solutions , Calpine Energy Solutions , Constellations NewEnergy, INC , Crius Energy , Direct Energy Services LLC , Dynegy , ENGIE Resources , Entrust Energy , IGS Energy , Just Energy , Liberty Power , Next Era Energy Services , Nordic Energy Services, LLC , NRG Energy INC , Source Energy , Spark Energy , Starion Energy , Stream Energy , Talen Energy , TransCanada Power Marketing LTD. 
The electric power industry covers the generation, transmission, distribution and sale of electric power to the general public and industry. The commercial distribution of electric power started in 1882 when electricity was produced for electric lighting. In the 1880s and 1890s, growing economic and safety concerns lead to the regulation of the industry. Once an expensive novelty limited to the most densely populated areas, reliable and economical electric power has become an essential aspect for normal operation of all elements of developed economies.