Secretary of Energy Rick Perry testifies during a House Energy and Commerce Committee hearing on Capitol Hill in Washington, D.C., on Oct. 12. Perry's proposed rule to benefit nuclear and coal power plants has been rejected by a federal regulatory commission. Drew Angerer/Getty Images hide caption
Communities like Barnegat Light, N.J., have seen debate over seismic research on the ocean floor. Wayne Parry/AP hide caption
Oklahoma Attorney General Scott Pruitt, shown in 2013, is President-elect Donald Trump's pick to head the EPA. Pruitt's outspoken criticism of climate change and his close ties to the energy industry have raised concerns about his ability to lead the agency. Sue Ogrocki/AP hide caption
After 43 years of cranking out electricity, the Fort Calhoun nuclear power plant is shutting down. The plant was licensed until 2033, but will go offline 17 years earlier than planned. United States Nuclear Regulatory Commission/Flickr hide caption
An oil company driver fills his truck at the Sprague terminal in South Portland, Maine, last winter. This winter, costs for heating with all fuels are expected to go up. Robert F. Bukaty/AP hide caption
Consumer advocates took to the streets of Phoenix recently to protest against an Arizona utility's efforts to bill customers using a so-called "demand charge." If approved, Arizona Public Service would be the first utility in the country to place most of its residential customers on that kind of rate plan. Will Stone/KJZZ hide caption
Logger Greg Hemmerich and his crew feed low-value trees into a wood chipper, before bringing the chips to ReEnergy Holdings' biomass plant in Lyonsdale, N.Y. David Sommerstein/NCPR hide caption
Eric Frumin (right) stands in front of his solar panels on the roof of his Brooklyn home alongside architect David Cunningham (left) and AeonSolar's Allen Frishman (center). Courtesy of Eric Frumin hide caption
Solar-powered lights make a dramatic difference in the lives of Tanzanians who had no electricity. Rachel Ambrose/Courtesy of Off-Grid Electric hide caption
One of the sites for the Department of Energy's Strategic Petroleum Reserve lies within salt caverns 2,000 feet below the ground near Freeport, Texas. Jeff Brady/NPR hide caption
U.S. Energy Secretary Ernest Moniz takes part in a press conference at the end of the 2015 meeting of the International Energy Agency Governing Board on Nov. 18, 2015 in Paris. ERIC PIERMONT/AFP/Getty Images hide caption
The sun sets over Alexandria, Egypt. The Brits brought daylight saving time to Egypt, but the country is currently DST-free. Peter Langer/Design Pics/Corbis hide caption
A world in light and dark: This satellite view shows where electric lights are in high usage. Buyenlarge/Getty Images hide caption