Case Studies >

First Solar Mesa Facility

  • Mesa, Arizona
  • 4 MW

COMPLETED: January 2013
CLIENT: First Solar, Inc.

Project Summary

The First Solar Mesa project is the largest rooftop installation in the state of Arizona with 18 acres of solar panels. The 4 MW photovoltaic (PV) system feeds power to First Solar’s Manufacturing Facility and exports excess generation to the local electric utility, Salt River Project (SRP).

Blue Oak Energy Scope

Full scope engineering, procurement, and construction (EPC).

Project Goals

The First Solar Mesa facility is a flagship monitoring headquarters and manufacturing facility and a perfect location to utilize First Solar’s advanced thin-film modules. The goals for installing the rooftop system included financial savings for reduced utility power purchase and accelerated return on investment using available federal tax incentives. The project is a test bed for advanced, large-scale PV technology, an integrated data acquisition and SCADA system, and load-side medium voltage interconnections. Because this system has the potential to export more than 1 MW of electric power to the local utility, the project was required to meet the SRP remote transfer trip control requirements for the facility’s medium voltage switchgear. Since the manufacturing facility loads are characterized by large and dynamic variations in reactive power, the PV inverters were selected to provide variable power factor output to optimally match the real-time building reactive vs. real power demand. A SCADA system was installed to enable automatic control of the inverter output power characteristics.

System Specifications

Panel Type: FS Series 3, FS-375
Panel Quantity: 54,840
Racking Type: FS Flush Mount
Inverter Type: Converteam Conversol NA1350F (x1)
Power-One ULTRA-1400 (x2)
System Size [DC]: 4.1 MWp
System Size [AC]: 3.4 MVA
DC Voltage: 1000 V
AC Voltage: 12.4 kV


Key Features

  • Largest rooftop PV system in the state of Arizona, with 18 acres of solar panel coverage.
  • 1000 V DC system with harness and cable tray wire management.
  • Advanced megawatt class inverters located indoors and outdoors.
  • Large equipment pad with cable troughs for future expansion and equipment testing.
  • Advanced SCADA control of inverter output, including real-time reactive power control.
  • Dual medium voltage switchgear load-side interconnections.
  • Utility remote transfer trip control of medium voltage switchgear interconnection breakers utilizing advanced communication protocols.