USA

Ajakirja NATIONAL GEOGRAPHICesikaane lugu SOLAR POWERTHE ELUSIVE PROMISE OF ENDLESS ENERGY PLUGGING INTO THE SUNSUNLIGHT BATHES US IN FAR MORE ENERGY THAN WE COULD EVER NEED-IF WE COULD JUST CATCH ENOUGH.At an electric plant in southern Spain,mirrors as big as houses catch some of the 120 quadrillion watts of sunlight that constantly fall on Earth.Government subsidies for this pricey yet promising power source have made Europe the world´s solar capital.Selle artikli juures on ilus pilt kus on tohutu ala kaetud päikse paneelidega ja elektrikud paigaldavad neid,särkide peale on kirjutatud GREEN ELECTRIC,ning tekst pildi juurde:Turning unused space into a power source for 1,300homes,Southern California Edison contractors cover a 14-acre warehouse roof near Los Angeles with some 33,000 lightweight photovoltaic,or PV,panels.California law requires ytilitiesto generate 20 percent of their power from renewable sources by 2010. Järgmise pildi peal mees seisab ruudulise RULLI keeratud KILE sees ja paremas käes hoiab põlevat elektripirni,tekst selle juurde on järgmine:As the lights come on in Los Angeles,solar evangelist Larry Kazmerski models 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.By George JohnsonPhotographs by Michael MelfordEarly 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 believe 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 operators in the control room.His job is to monitor the rows of parabolically shaped mirrors as they concentrate sunlight on long steel pipes filled with circulating oil,heating it as high as 750 degrees Farhenheit.From the mirror field,the blistering liquid pours into giant radiators that extract the heat and boil water into steam.The steam drives a turbine and dynamo,pushing as much as 64 megawatts onto the grid-enough to electricity 14,00 households or a few Las Vegas casinos."Once the system makes steam,it´s very traditional-industry-standard stuff,"says plant manager Robert Cable,pointing toward a gas-fired 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 first 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 generates electricity here and sells it to NV Energy,the regional utility.The mirrors were made in Germany. Putting on hard hats and dark glasse,Cable and I get into his pickup and drive slowly past row after row mirrors.Men with a water truck are hosing down some."Any kind of dust affects them,"Cable says.At the far edge of the mirror field,we stop and step out of the truck for a closer look.Above his head,at the focal point of the parabola,the pipe carrying the oil is coated with black ceramic to soak up the light,and it´s encased in an airless glass cylinder for insulation.On a clear summer day with the sun directly overhead,Nevada Solar One can convert about 21 percent of the sun´s rays into electricity.Gas plants are more efficient,BUT THIS FUEL IS FREE.And it doesn´t emit planet-warming carbon dioxide.Jätkub...Elagu konkurents!