| − | ''Alternative energy'' is energy sources such as solar, wind, and geothermal power, that is, energy sources that are renewable and do not pollute the environment. | + | '''Alternative energy''' is energy sources such as solar, wind, and geothermal power, that is, energy sources that are renewable and do not pollute the environment. However, alternative energy is often more expensive than conventional energy sources, and only federal subsidies make it cost-effective. |