Topaz Solar Farm, CA


Installing the racking system for the solar array

Installing the racking system for the solar array


  • Fast-tracked project:  EIS completed in 11 months
  • 550 MW; at the time largest PV solar plant in the US at the time (now second largest)
  • Created 400 construction jobs
  • $2.5 billion dollar project
  • Includes 9 million solar panels
The completed solar array covering 3,500 acres

The completed solar array covering 3,500 acres

EMPSi prepared a Draft and Final EIS for the complex Topaz Solar Farm in eastern San Luis Obispo County, California. The 550-MW facility comprised about nine million photovoltaic panels within approximately 437 arrays and associated electric equipment on 3,500 acres. The project is interconnected with PG&E’s existing Morro Bay-Midway 230-kV transmission line.

Because the California Independent System Operator determined that network upgrades of the transmission line would be required to accommodate part of the project, as well as other generation projects in the region, the transmission line upgrade was also analyzed in the EIS. These network upgrades include re-conductoring 35 miles of 230-kV transmission lines between a new PG&E switching station and the Midway substation.

Technical issues included biological resources, prime farmlands, floodplains, water resources, visual resources, and land use. EMPSi interacted extensively with DOE headquarters staff. Fewer than 12 months elapsed from scoping to the final compliance document. 

I was just reminiscing back on last year, and I thought of what a pleasure it has been to work with EMPSi.  You guys have been some of the best consultants I’ve ever worked with, and I will recommend you to anyone who asks!

— First Solar