What is Renewable/Alternative Energy?

Because of concerns over climate change and dependence on foreign oil, we are constantly scrambling to find alternative energy sources that are cleaner, safer, and renewable.  But what is "Alternative/Renewable Energy," and how is it important to our future on this planet?

The European Union (EU Directive 2001/77/EC) defines renewable energy as "non-fossil energy sources (wind power, solar power, geothermal, wave, tidal, hydropower, biomass, landfill gas, sewage treatment plant gas, and biogases)."

Renewable energy sources come from resources readily available such as biomass (unused waste or residue like plant/animal matter, wood etc) or from sources that are natural (solar power, hydropower, wind power).

There are several major benefits to using renewable energy—unlike fossil fuels, renewable energy is plentiful.  We are never going to run out of garbage to provide biomass and if the sun ever stops shining, solar power will be the least of our worries.  Sustainable energy sources also tend to pollute far less than energy derived from fossil fuels.  In fact, solar power, hydropower, and wind power are all virtually pollution free—a major benefit given the growing concern over rising CO2 levels caused by various human activities on the planet.  This is why you often hear renewable energy referred to as "green energy" or "green power."

Another potential long term benefit to using renewable energy sources is cost.  Oil and natural gas prices are impacted by global economies, natural disasters, wars, and sometimes simple greed, but a wind turbine or a photovoltaic panel keeps on working as long as it is maintained; the sun shines and the wind blows for absolutely free.