S&C Case Study: Picture Rocks Solar Farm

The original developer of the Picture Rocks Solar Farm in Marana, Ariz., wanted to connect its 20-MW plant to the local utility grid by the end of 2012. Using nearly 90,000 PV modules, the new plant would provide power sufficient for 3,500 homes, and help meet Arizona’s goal of generating 15% of the state’s energy from renewable energy sources by 2025. To meet the energization deadline and secure project funding, the developer turned to S&C Electric Company.

S&C was able to compress the typical 90-day project to 50 days. With its vast renewable energy expertise and input from the utility, S&C developed the preliminary substation design and provided the estimates that the developer needed to secure financing for the project. This preliminary design work was instrumental in meeting the energization deadline, since it allowed procurement of substation materials and equipment to commence almost immediately, including the controls and metering equipment which connect the plant’s 34.5-kV collector system to the utility’s 46-kV transmission substation.

In addition to supplying S&C System VI Switchgear and a 69-kV S&C Series 2000 Circuit Switcher, S&C procured a 20-MVA power transformer, a grounding transformer, all substation steel and medium-voltage underground cable. Because S&C worked closely with the utility during the design phase, approval to construct was received promptly. The construction phase was further accelerated by S&C’s ability to manufacture and ship the System VI Switchgear — which is designed specifically for solar plants — in a compressed time frame.

Based on S&C’s Vista Underground Distribution Switchgear that’s used in thousands of applications worldwide, System VI Switchgear helps standardize the design of solar plants and cut installation time. Since System VI Switchgear features a relay enclosure, S&C was able to construct the substation without the need for a control building reducing costs and construction time.

Throughout the project, S&C maintained on-site safety and quality control. S&C also conducted substation equipment testing and commissioning. In addition, S&C tested all of the relaying and monitoring systems to ensure proper operation.

S&C completed the Picture Rocks Solar Farm connection substation project six weeks ahead of schedule, within budget and without any recordable safety incidents. Swift project completion enabled the developer to energize the plant before the December 21, 2012 deadline, and maximize their return on investment. Picture Rocks Solar Farm currently provides 20 MW of clean energy to Arizona’s grid, helping meet the state’s renewable energy goals.

S&C Electric will exhibit at Intersolar North America 2014 in booth 8221.