Producing energy from fossil fuels is a dirty, expensive but hugely profitable enterprise. At some point we will have exhausted all the easily accessible sources of fossil fuel and will have to turn to other, cleaner, renewable energy sources. Jeremy Shere looks at what those alternatives will be. In Renewable: The World-Changing Power of Alternative Energy, he tours a traditional coal-fueled power plant, a solar farm at Denver’s airport, attends a Wind Power Expo and a wind farm tour in Texas, and investigates turbines deep in New York City’s East River. He explains the most promising types of renewable energy: namely, biofuel, solar, wind, geothermal, and hydropower.