What is the definition of alternative energy?
Concerns about the environment and climate change have led to policies aimed at promoting alternative energy to replace traditional coal, oil, gas and nuclear energy sources. The term alternative energy refers to some different types of energy technologies.Renewable energyAlternative energy has traditionally referred to renewable energy sources such as solar, wind, small hydropower, geothermal and biomass. Renewable energy sources are not permanently depleted like fossil fuel energy sources.Environmental impactsAlternative energy sources release significantly less air pollution and greenhouse gases than conventional fossil fuel sources, do not cause severe land degradation like coal mining, and do not produce any hazardous waste like nuclear energy.VariationsUnder the Bush administration, the term alternative energy was expanded to include ethanol, methanol, biodiesel, and coal-to-liquids. Some definitions also include hydrogen fuel.ControversyThe environmental benefits of some of thes
