Now the equation is showing significant signs of change. Costs are falling for some alternative-energy sources, driven by new technology and renewed development interest. The math looks even more favorable if you consider the environmental cost of fossil fuels -- which most purely economic calculations don't.
Geothermal energy -- tapping heat deep in the Earth to generate power -- may have more potential, at less impact to society, than any of the other alternative resources. A new study on geothermal energy, produced by an interdisciplinary team at the Massachusetts Institute of Technology, found that geothermal energy could produce 10% of the nation's electricity by 2050 at prices that would be competitive with fossil fuels.
