PBS NewsHour continues their energy series with a visit to Colorado. Coal has been a traditional source of electrical energy in the state, but now a new energy source - natural gas - is making inroads.
Indonesia, the country with the world's largest number of active volcanoes, is betting that all the hot rocks will provide a clean and reliable energy source for the future.
The country is believed have 40 percent of the world's geothermal energy resources. But making geothermal energy economically feasible will require adjusting the country's heavily subsidized energy prices. And that issue is a political hot potato.