Nine million cadmium telluride solar modules now cover part of Carrizo Plain in southern California. The modules are part of Topaz Solar Farm, one of the largest photovoltaic power plants in the world. At 9.5 square miles (25.6 square kilometers), the facility is about one-third the size of Manhattan island, or the equivalent of 4,600 football fields.
Construction at Topaz began in 2011. The plant was mostly complete by November 2014, when it was turned on and began to generate electricity. By February 2015, all construction activity ended and plant operator BHE Renewable was set to announce that the project was officially complete. When operating at full capacity, the 550-megawatt plant produces enough electricity to power about 180,000 homes. According to BHE estimates, that is enough to displace about 407,000 metric tons of carbon dioxide per year, the equivalent of taking 77,000 cars off the road.
From the ground level, the scope of the facility is difficult to comprehend. Visitors to Topaz describe rows of solar panels that seem to stretch endlessly into the horizon. This satellite image, captured on January 2, 2015, by the Operational Land Imager on Landsat 8, helps put the facility into perspective. Solar arrays appear gray and charcoal. The surrounding farmland and grasslands appear brown and green. The power plant is situated within a plain flanked by the Caliente Range to the west and the Temblor Range to the east.
Topaz’s solar modules are mounted together on panels supported by steel columns; the structure holds the modules about 5 feet (1.5 meters) above the ground. Rows of panels are laid in a way that form large geometric shapes that are defined in part by the presence of access roads, stream beds, and preexisting infrastructure. The northernmost portions of the solar farm, which are close to a transmission line, were built first.
Mid American Renewables and Gunther Portfolio have published interesting aerial video and photographs that show additional views of the plant at various stages of construction.
A Earth Observatory image by Jesse Allen, using Landsat data from the U.S. Geological Survey. Caption by Adam Voiland.
