World’s Largest Solar Array Set to Crank Out 290 Megawatts of Sunshine Power - Scientific American

World’s Largest Solar Array Set to Crank Out 290 Megawatts of Sunshine Power - Scientific American
The plant comprises more than five million solar panels that span the equivalent of two Central Parks in the desert between Yuma and Phoenix. It generates 290 megawatts of power—enough electricity to fuel 230,000 homes in neighboring California at peak capacity. The Agua Caliente Solar Project represents a significant advance in the technology compared with just four years ago, when the largest solar facility in the U.S. generated only 20 megawatts. “Solar has completely arrived as a competitive energy resource,” says Peter Davidson, executive director of the Loan Programs Office at the U.S. Department of Energy (DoE).

The project, which cost a total of $1.8 billion to construct, received a million-dollar loan from the Loan Programs Office. Under its “SunShot” initiative (so-named in the spirit of president John F. Kennedy’s “moon shot” program), the DoE provides guaranteed loans to unproved ventures in solar power in the hopes of promoting innovation and making the technology more cost-effective.* Although Agua Caliente (owned by U.S. energy giant NRG Energy and partner MidAmerican Solar) is now the largest photovoltaic solar facility in the world, it probably will not hold that distinction for long. Other massive solar panel facilities, such as Antelope Valley Solar Ranch One in California’s Mojave Desert, are rapidly springing up across the Southwest. “This series of large plants that are being built really mark the transition from the technology being something experimental to real energy on the grid,” agrees Robert Margolis, a senior analyst at the National Renewable Energy Laboratory (NREL). Solar power currently accounts for 1 percent of U.S. energy production, but it is the fastest-growing sector of the energy landscape. Margolis says that Agua Caliente proves that investing in solar power on a large scale is an effective way to make it more viable in the current market.

The energy contained in just one hour of sunlight could power the world for a year, if only it could be harnessed. Traditional solar panels made from silicon—the gold standard of semiconducting material—are expensive, however, particularly in comparison with cheap but dirty coal and natural gas. Agua Caliente, which is operated and maintained for NRG by Tempe, Ariz.–based First Solar, uses newer, thin-film panels that that absorb the same amount of sunlight with a fraction of the material, boosting the array’s efficiency.