Kevin Murphy says he is proud of what he and the other workers do at the Rosebud mine, including digging the coal and reclaiming the land afterward. Amy Martin/Montana Public Radio hide caption

itoggle caption Amy Martin/Montana Public Radio

A wind farm in Montezuma Hills, about 40 miles northeast of San Francisco. California is considering proposals to, among other things, derive half the state's electricity from renewable sources. Carl Costas/CALmatters hide caption

itoggle caption Carl Costas/CALmatters

There are about 400,000 greater sage grouse left on the landscape, spread across 11 Western states, from California to North Dakota. That's a fraction of what their numbers were just a century ago. Tom Koerner/U.S. Fish and Wildlife Service hide caption

itoggle caption Tom Koerner/U.S. Fish and Wildlife Service

An aerial view of Tokyo Electric Power Co.'s tsunami-crippled Fukushima Dai-ichi nuclear power plant, on March 11. Kyodo/Reuters/Landov hide caption

itoggle caption Kyodo/Reuters/Landov

A thermoelectric PowerCard like this one can be used to convert waste heat into an electric power source, Alphabet Energy says. Alphabet Energy hide caption

itoggle caption Alphabet Energy