The Noor I Concentrated Solar Power plant, shown on Thursday, is the first phase of a large solar thermal power plant that is intended to supply more than a million Moroccans with electricity. Fadel Senna/AFP/Getty Images hide caption

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Consumers have been benefiting from lower gas prices. Here, prices dip below $2 per gallon at an Exxon station in Woodbridge, Va., on Jan. 5. Saul Loeb/AFP/Getty Images hide caption

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A woman attends a public hearing about the gas leak before the South Coast Air Quality Management District. The agency has ordered Southern California Gas Co. to permanently shut down the well, and is suing the company for negligence. David McNew/Getty Images hide caption

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"Solar trees," which suspend solar panels over parking spaces in San Diego, collect electricity. Generating solar power like this is just one rung on a ladder the city will have to climb to reach 100 percent renewable energy by 2035. Clare Trageser /KPBS hide caption

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A Porter Ranch resident wears a gas mask during a protest Saturday outside a meeting of the Air Quality Management Board over the Aliso Canyon gas leak. The leak started in October and has forced thousands of residents to flee from the Los Angeles suburb of Porter Ranch. Regulators have ordered the gas company to shut down the leaking well; some residents want the entire facility shuttered. Mark Ralston/AFP/Getty Images hide caption

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A customer fills up at a gas station in Chillicothe, Ill., in December. Low prices have meant big savings for consumers, but urban planners worry that cheap gas will encourage sprawl. Bloomberg/Bloomberg via Getty Images hide caption

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Passengers walk through the terminal as they head to their flights at Reagan National Airport in Arlington, Va., on Dec. 23, 2015. Saul Loeb/AFP/Getty Images hide caption

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The plastic sheet invented by Stanford University chemical engineer Zhenan Bao and her colleagues can be inserted in lithium-ion batteries to avoid overheating. Zheng Chen/Courtesy of Zhenan Bao hide caption

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U.S. Secretary of State John Kerry (left) meets with Iranian Foreign Minister Mohammad Javad Zarif (right) in Vienna on Saturday. The International Atomic Energy Agency, or IAEA, has verified that Iran has met all conditions under the nuclear deal. Kevin Lamarque/AP hide caption

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