September 1, 2009

Top Plants: Edward W. Clark Generating Station, Clark County, Nevada

Dr. Robert Peltier, PE

Owner/operator: NV Energy Inc.

The Edward W. Clark Generating Station, which has supplied electricity to the Las Vegas Strip for more than half a century, has learned the secret of life in the desert: adaptability. The plant’s early years featured conventional steam plants operated around the clock. By mid-life, Clark had been upgraded with two combustion turbine combined-cycle power blocks operated as intermediate-load resource. Today, the old steam plants have been replaced with fast-start peaking gas turbines.

NV Energy’s Edward W. Clark Generating Station, located a few miles south of the Las Vegas Strip, is a case study of how the power industry has evolved over the past half-century. Until Clark was built as Nevada Power’s first power plant, Hoover Dam was the company’s sole source of electricity. The first unit was built at Clark in 1955, the same year that the Riviera Hotel became the Strip’s first high-rise — at nine stories. That first 70-MW unit was soon joined by two additional units that increased the plant’s rating to 175 MW, enough to supply the 100,000 residents of the entire Las Vegas Valley.

Today, the Las Vegas Valley’s population has eclipsed 1.4 million residents, and NV Energy — formed by the merger of Nevada Power, Sierra Pacific Power, and Sierra Pacific Resources in 1999 (the two operating companies changed their names to NV Energy in 2008) — serves 2.4 million Nevadans. Then-Sierra Pacific Resources’ 541-MW Tracy Combined Cycle Plant, located east of Reno, was selected as a 2008 POWER Top Plant in recognition of its construction as the first new power plant built in northern Nevada in 24 years and for reducing expensive out-of-state power purchases.

NV Energy has doubled its company-owned generation since 2006, pushing its peak demand from about 2,500 MW to about 5,700 MW in 2008. The coincident peak demand on its system in 2008 was 7,152 MW, with the difference made up by contract power purchases. The planning reserve margin for southern Nevada is 12%.