Bill Pentak of Panda Power Funds (left), Plant Manager John Martin (center) and Construction Manager Rob Risher (right) stand in front of the construction site for the new Panda Liberty gas power plant in Towanda, Penn. The plant, expected to come online in early 2016, was deliberately sited on top of the Marcellus Shale to take advantage of the cheap, abundant gas. Marie Cusick/WITF hide caption

itoggle caption Marie Cusick/WITF

Oil trains sit idle on the BNSF Railway's tracks in Chicago's Pilsen neighborhood. David Schaper/NPR hide caption

itoggle caption David Schaper/NPR

Pump jacks and wells work in an oil field on the Monterey Shale formation in California. Economist Michael Porter says that hydraulic fracturing, or fracking, is a "game changer" for the U.S. economy. David McNew/Getty Images hide caption

itoggle caption David McNew/Getty Images