A Spanish breakthrough in harnessing solar power

Source Smithsonian

Amid the green wheat fields, oak groves and ancient olive trees of Andalusia, a giant solar energy farm shimmers like a silver sea. Even under cloudy skies, the arrays of mirrors and massive towers sprawling over three square miles are an arresting sight. Twenty miles west of Seville, the SolĂșcar solar farm, built by the company Abengoa, is part of Spain's push to produce more energy from renewable sources. The nation currently produces up to 3.65 gigawatts of power from the sun, second in the world after Germany. Those gigawatts make up about 3 percent of the country's power, the highest percentage in the world. (The United States generates less than 1 percent of its energy from the sun.) Spain's solar output is expected to rise in the next three years to seven gigawatts, enough to supply about ten million people"the combined population of Madrid and Barcelona"with electricity during the day. The SolĂșcar farm is pioneering technologies that are being replicated in the United States, including concentrated solar power, or CSP. While traditional solar panels use photovoltaic cells to convert the sun's rays directly into electricity, CSP deploys huge banks of mirrors to focus solar radiation; the intense heat drives steam turbines, producing electricity in a process similar to the one used in coal-or oil-fired plants, but without the greenhouse gas emissions.