National Geographic : 2009 Sep
• EBY GEORGE JOHNSON PHOTOGRAPHS BY MICHAEL MELFORD As the lights come on in Los Angeles, solar evangelist Larry Kazmerski models the latest in PV: bendy thin-film panels that fit so many places, says the National Renewable Energy Laboratory researcher, they could one day power whole cities. "This is going to be on every roof and building," Kazmerski says. Early on a clear November morning in the Mojave Desert, the sun is barely touching the peaks of the McCullough Range with a cool pink glow. Behind them, a full moon is sinking over the gigawatt glare of Las Vegas. Nevada Solar One is sleeping. But the day s work is about to begin. It is hard to imagine that a power plant could be so beautiful: 250 acres of gently curved mirrors lined up in long troughs like canals of light. Parked facing the ground overnight, they are starting to awaken---more than 182,000 of them---and follow the sun. "Looks like this will be a 700-degree day," says one of the opera- tors in the control room. His job is to monitor the rows of para- bolically shaped mirrors as they concentrate sunlight on long steel pipes lled with circulating oil, heating it as high as 750 degrees Fahrenheit. From the mirror eld, the blistering liquid pours into giant radiators that extract the heat and boil water into steam. e steam drives a turbine and dynamo, pushing as much as 64 megawatts onto the grid---enough to electrify 14,000 households or a few Las Vegas casinos. "Once the system makes steam, it s very traditional---industry-standard stu ," says plant manager Robert Cable, pointing toward a gas- red power plant on the other side of Eldorado Valley Drive. "We get the same tools and the same parts as the place across the street." When Nevada Solar One came on line in 2007, it was the rst large solar plant to be built in the United States in more than 17 years. During that time, solar technology blossomed elsewhere. Nevada Solar One belongs to Acciona, a Spanish company that gen- erates electricity here and sells it to NV Energy, the regional utility. e mirrors were made in Germany. Putting on hard hats and dark glasses, Cable and I get into his pickup and drive slowly past row a er row of mirrors. Men with a water truck are hosing down some. "Any kind of dust a ects them," George Johnson is the author of e Ten Most Beautiful Experiments and seven other books. Michael Melford is a regular contributor; his photos on Herod the Great appeared in the December 2008 issue.