The Future of Energy: Earth, Wind,
 Water

By Eric A. Powell

Strip our biggest sources of energy to their most elemental, and you are left with fire—the burning of fossil fuels. To build a sustainable energy future, we will have to start relying a lot more on the other three classical elements: water, wind, and earth. This year, discover teamed up with the American Society of Mechanical Engineers, the Institute of Electrical and Electronics Engineers (ieee, and the National Science Foundation to bring leading energy experts to Capitol Hill, where they briefed Washington insiders and charted the scientific, technological, and political challenges that lie ahead on the road to a new energy economy.

1 EARTH: Tap Into the Heat Beneath Your Feet
THE CHALLENGE Geothermal energy has been around so long that it hardly deserves to be called “alternative”; people have been tapping hot water below the Earth’s surface to generate electricity for a century. But geothermal accounts for only about 16 terawatt-hours a year in the United States, less than half of 1 percent of total electricity consumption. As with wind energy, geothermal is simple in principle but hard to do successfully in practice. Too often, drilling results in wells that are hot but have no water or wells that are simply not hot enough. A symptom of the industry’s woes is that federal funding for geothermal energy has fallen from about $450 million in 1979 (in 2011 dollars) to below $50 million this year.
 
THE NEW ENERGY ECONOMY Geophysicist David Blackwell of Southern Methodist University says that lack of attention is a mistake. He estimates that there are 100 to 500 gigawatts of potential geothermal energy locked beneath the United States. What is needed to successfully exploit all that energy, according to Nevada geologist James Faulds, is investment in more detailed geologic mapping, three-dimensional modeling of underground water flows, and 
testing of water chemistry that can indicate the temperature of subsurface waters. More surveys of ancient hot springs, which can point to the locations of still-active geothermal systems, would help too....