Nevada Power Company was a Las Vegas-based company that produced, distributed, and sold electricity in the southern part of the state of Nevada. In 2005, it had over 700,000 electric customers in parts of three Nevada counties — a service area of more than 4,000 square miles (10,000 km2). In 1998, Nevada Power merged with Nevada's other major utility, Sierra Pacific Resources. It continued as a subsidiary of Sierra Pacific until 2005, when the company changed its name to NV Energy.
Nevada Power was founded on March 20, 1906 as Consolidated Power and Telephone, the electric and telephone company for the year-old town of Las Vegas. It split into two companies in 1929. The telephone company, Southern Nevada Telephone Company, eventually was acquired by Centel. It was later owned by Sprint and Embarq, and is now part of CenturyLink. The power company became Southern Nevada Power. In 1937, it became the first utility to receive power from the Hoover Dam. As the Las Vegas Valley boomed in the 1950s, its power needs exceeded the power available from the dam, and Southern Nevada Power began building its own steam turbines. After buying the Elko-Lamoille Power Company, it was renamed Nevada Power in 1961. A year later, it became the first Nevada company on the .
In 1999, the company merged with Sierra Pacific Resources of Reno, the main electric and natural gas provider for northern Nevada. The merged company retained the Sierra Pacific name, but moved its headquarters to Las Vegas.
In the late 1990s and early 2000s, Nevada Power held off on building new plants and was looking to divest its existing plants based on Nevada's deregulation of power generation and distribution. However, after the energy crisis in 2001, the deregulation was put on hold and Nevada Power resumed pursuing options to generate more of its own power.
In 2003 the company installed two of the largest phase shifting transformers in the world at its Crystal switching station to deal with the large quantity of imported power.