Description: MYR subsidiary Sturgeon Electric completed this 238.28 kW DC photovoltaic installation that was designed to supply all energy required to run the dairy. A program was developed that allows Zimmerman Dairy to avoid monthly energy costs and substitute them for long- term debt service through the use of net metering. Under net metering, a system owner receives retail credit for a portion of the electricity they generate. By installing solar panels, the dairy owners’ electric bill is fixed at 25 percent of what they were previously paying. The dairy requires nearly 50 kilowatts (kW) an hour per day to function, and the solar panels allow the dairy to produce three times that much energy per hour. This surplus energy is sent to an SRP (Salt River Project- one of Arizona’s largest utilities) meter and fed back into an SRP grid. When the sun stops shining, SRP sends the electricity back to the dairy free of charge.
Because the array was located a great distance from the systems distribution gear, Sturgeon designed the system to include two step up transformers (480V to 12,470V) and two step down transformers (12,470V to 240/120V) that feed two 800A service entrance sections which in turn feed two 400A panels that feed the existing loads located within the dairy.
Completion Date: 2011
Work Performed By: Sturgeon Electric Company, Inc., a subsidiary of MYR Group
Client: Professional Engineers Dairy