Solar Power Array Maintains Record Status

Tucson Electric Power Company’s giant solar array continued to grow in 2003, holding its position as the world’s second largest photovoltaic (PV) power plant. The Springerville Generating Station Solar System (SGSSS) has reached 3.78 MW in size, giving it enough capacity to satisfy the annual electric energy needs of more than 630 Tucson homes.

Springerville, Arizona – December 16, 2003 [] The system is the largest of its kind in the Western Hemisphere and second in the world only to a 4 MW PV solar system at Hemau, Germany. The SGSSS covers 38 acres in the high desert grasslands of Eastern Arizona near TEP’s coal-fired Springerville Generating Station. It incorporates 28 individual PV systems built around either crystalline-silicon, thin-film amorphous-silicon or thin-film cadmium-telluride modules. Multiple technologies are being used to help determine which will work most efficiently, and to optimize installation costs for the different technologies. To date, the 28 systems include: – Twenty systems composed of 450 ASE DG-50 DG-50 PV panels. Each module produces 300 watts DC, and they are connected in strings of nine modules, producing an average annual DC bus voltage of 420 volts. – Four systems composed of between 2,688 and 3,024 First Solar FS45 and FS50 modules. Those panels are rated at 45 to 50 watts apiece. They are connected six panels to a string, producing an average annual DC bus voltage of approximately 320 volts. – Four systems composed of 3,000 BP Solar MST-43 Modules. These 43-watt panels are connected five to a series loop and produce an average annual DC bus voltage of approximately 300 volts. Global Solar Energy, a manufacturer of flexible thin-film PV material as well as a solar system integrator, has been the project manager for the SGSSS. Southwest Energy Solutions has served as the electrical contractor for the system. Both companies are subsidiaries of UniSource Energy Corporation, TEP’s parent company. TEP plans to continue expanding SGSSS until it reaches a capacity of 8.6 MW by the end of 2010. The system already accounts for the bulk of TEP’s 4.3 MW of solar generation capacity, which also includes smaller company-owned arrays in Tucson and over 160 kW of TEP-subsidized PV systems installed by the utility’s customers.