Five years of operating experience at a large, utility-scale photovoltaic generating plant

Tucson Electric Power Company (TEP), headquartered in Tucson, AZ, currently has nearly 5.0 MWdc of utility-scale grid-connected photovoltaic (PV) systems installed in its service territory. These systems have been installed through a multiyear, pay-as-you-go development of renewable energy, with kWhac energy production as a key program measurement. This PV capacity includes a total of 26 crystalline silicon collector systems, each rated at 135 kWdc for a total of 3.51 MWdc, that have been installed at the Springerville, AZ generating plant by TEP making this one of the largest PV plants in the world. This facility started operations in 2001 and recently passed the 5-year milestone of continuous operations. These systems were installed in a standardized, cookie-cutter approach whereby each uses the same array field design, mounting hardware, electrical interconnection, and inverter unit. This approach has allowed TEP to achieve a total installed system cost of $5.40/Wdc and a TEP-calculated levelized energy cost of $0.062/kWhac for PV electrical generation. This paper presents an assessment of operating experience including performance, costs, maintenance, and plant operation over this 5-year period making this one of the most detailed and complete databases of utility-scale PV systems available to the US DOE Program. Published in 2007 by John Wiley & Sons, Ltd.