Harper Lake - SEGS VIII and IX

Harper Lake Solar Power Plants- Southern California

Harper Lake, Barstow, California

Introduction

The two largest solar fields in the world are located at Harper Lake in San Bernadino County Southern California (SEGS VIII and SEGS IX). The plants have a combined electrical capacity of 160 MW.

Luz Industries built the two plants SEGS VIII and IX in 1989 and 1990. These two plants were the last and most advanced to be built.  The plants were planned to be larger than the previous seven plants, and to take advantage of the economies of scale. They have operated continuously and have been commercially successful since that time.

System Description

The site for SEGS IX was selected due to the high solar insolation levels (intensity of sunshine in watts/ square meter) in this part of the Mohave desert. Other favorable sitting factors such as excellent water resources, relatively level land,  proximity to electric transmissions facilities and natural gas lines.

At the two Harper Lake plants some advancements were made, as a result of experience gained from the previous seven plants with the broad objective of improving economies of scale. The advances include;

• The size of the plant was increased to 80MW
• A newer larger collector design (LS-3) was introduced which reduced the required number of tracking components and reduced costs 
• A natural gas fired Heat Transfer Fluid heater replaced the natural gas boiler as the means to supply steam in the gas-fired mode of operation

SEGS IX is comprised of a solar field, power block and major plant services that include; fire protection, gas supply, power transmission lines water supply and treatment supply. The solar field power block and ancillary system cover an area of about 416 acres with the axes of the solar collector assemblies oriented in the north-south direction. The power block is located near the center of the solar field and covers an area of approximately 3 acres.

Solel Solar Systems has tested its improved collector tube the Universal Vacuum Collector UVAC in the field at Harper Lake and has achieved excellent results with a 30% increase in the efficiency of the solar field on a yearly average,

Description of the plant

• Two fields of 80 MW each
• No. of mirrors - 400,000
• Solar field size - 1,000 acres
• Florida Power and Light - part owner
• Regulatory Classification - Small Power Producer
• Radiation amongst the highest in the world
• Operational since 1989
• Produces 0.45% of California Grid