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Solar Electric Generating Station I

This page provides information on Solar Electric Generating Station I, a concentrating solar power (CSP) project, with data organized by background, participants, and power plant configuration. SEGS I is one of the nine Solar Electric Generating Station plants in California’s Mojave Desert. The combined electric generating capacity of these plants, which use parabolic trough technology, is more than 350 megawatts. The plants operate as Qualifying Facility Independent Power Producers under the Public Utility Regulatory Policies Act, with a special Standard Offer 2 type of power purchase agreement to Southern California Edison. Initially, the entire plant had three hours of thermal energy storage for dispatching electricity during periods of peak demand. However, a fire in 1999 damaged the storage system and it was not replaced.

Status Date: April 14, 2017
Photo with a high aerial perspective of hundreds of rows of parabolic troughs, with separate sections offset slightly from one another. A main power plant is shown in the middle of the field of troughs. Agricultural fields in the background show circular irrigation patterns.
Project Overview
Project Name: Solar Electric Generating Station I (SEGS I)
Country: United States
Location: Daggett, California
(Mojave Desert)
Owner(s): Cogentrix (100%)
Technology: Parabolic trough
Turbine Capacity: Net: 13.8 MW Gross: 13.8 MW
Status: Currently Non-Operational
Start Year: 1984

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Technology: Parabolic trough
Status: Currently Non-Operational
Country: United States
City: Daggett
State: California
County: San Bernardino
Region: Mojave Desert
Lat/Long Location: 34°51′ 47.0″ North, 116°49′ 37.0″ West
Solar Resource: 2,725 kWh/m2/yr
Source of Solar Resource: National Solar Resource Data Base
Contact(s): Phillip Jones
Company: Cogentrix
Start Production: December 20, 1984
Project Type: PURPA Qualifying Facility Independent Power Producer, with special Standard Offer 2 (SO-2) type power purchase agreement to Southern California Edison
Incentives: Accelerated depreciation
Federal and state investment incentive
Solar property tax exclusion


Developer(s): Luz
Owner(s) (%): Cogentrix (100%)
Operator(s): Cogentrix
Generation Offtaker(s): Southern California Edison

Plant Configuration

Solar Field

Solar-Field Aperture Area: 82,960 m²
SCA Manufacturer (Model): Luz (LS-1)
SCA Description: Parabolic trough SCA
Solar-Field Outlet Temp: 307°C

Power Block

Turbine Capacity (Gross): 13.8 MW
Turbine Capacity (Net): 13.8 MW
Power Cycle Pressure: 40.0 bar
Turbine Efficiency: 31.5% @ full load
Fossil Backup Type: None

Thermal Storage

Storage Type: 2-tank direct
Storage Capacity: 3 hour(s)
Thermal Storage Description: Storage system was damaged by fire in 1999 and was not replaced