Two Siemens Flex-Plant 10 combined cycle islands power California with 550 MW

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NRG Energy Inc. and Siemens Energy Inc. recently dedicated the El Segundo Energy Center located near Los Angeles, California. This is the second Flex-Plant to open in California after the nation's first in Lodi that went into commercial operation last year. Siemens Energy has supplied and commissioned the two Flex-Plant 10 combined cycle power islands. In total, they have an installed capacity of 550 MW – enough to supply efficient and flexible electricity to approximately 450,000 Californian homes.

For El Segundo Energy Center Siemens delivered two power islands – each featuring the main components, an SGT6-5000F gas turbine, an SST-800 steam turbine, an SGen6-1000A generator, an SGen6-100A-2P generator as well as a heat recovery steam generator, and an air-cooled heat exchanger. Siemens also supplied the complete electrical equipment and the SPPA-T3000 power plant instrumentation and control system, and also provided the engineering services and commissioning of the plant.


With the SGT6-5000F gas turbine integrated with a single-pressure, non-reheat bottoming cycle, and an air-cooled heat exchanger for steam condensing, this Flex-Plant 10 is expected to provide a net efficiency of nearly 49 percent – much higher in efficiency than conventional simple cycle solutions. This plant type is also said to be environmentally friendly, as compared to conventional combined cycle technology with a reduction of 95 percent of CO start up emissions and low water consumption. Additionally, the fast start capability is said to make it well suited to stabilize the grid and balance fluctuating renewable power generation.

This plant also recently demonstrated Siemens Clean-Ramp(TM) Technology which reduces transient emissions, while the gas turbines ramp up and down to meet electricity demands. In addition to having a small environmental footprint, El Segundo was optimized for the site size constraints, and also supported parallel demolition and construction efforts saving project schedule and cost.

Owned and operated by NRG Energy, El Segundo Energy Center is an environmentally compatible, combined cycle solution for peaking and intermediate load. The two units can achieve 300 MW in less than 10 minutes, allowing the plant to back up intermittent renewable power generation, such as wind and solar power, to maintain a steady, consistent and reliable supply of power to the grid.