 Renewable energy is energy which comes from natural resources such as sunlight, wind, water, and geothermal heat, which are renewable within a REASONABLE period of time.

 A term used to describe energy sources that exist in a limited amount on Earth and are utilized at a rate faster than they can be replenished.

 Solar energy is defined as “energy derived from the sun in the form of solar radiation.”  Solar energy is used in a variety of applications such as heating water, heating homes, and creating electricity, and many more applications are still being produced.

 Passive solar is considered to be in use when the sun is providing some form of energy without any use of mechanics.  Some examples of passive solar are heating a home through strategically placed windows, or heating a house’s water tank located on the outside of the home.

 Active solar on the other hand is considered to be in use when the sun is providing some form of energy through the use of mechanics.  Some examples of active solar are heating a house’s water via energy collected by a panel outside of the house, and solar arrays that move to follow the sun allowing them to catch more sunlight throughout the day.

 Photovoltaics are solar panels which are used to capture energy which is then transferred to electricity.  This form of solar energy has seen a huge increase in popularity recently as they can be installed almost anywhere where there is a significant amount of light and can cut down on an electric bill.

 Daylighting is a form of passive solar in which large windows are placed on a house to allow the house to be well lit and heated by the sun allowing for a decrease in reliance on electrical systems serving the same purpose.

 A solar power tower is a large tower constructed in the middle of a field of solar arrays which reflect light at the tower.  The tower can be filled with water that is heated by the sun, or photovoltaics which would transfer the sun’s energy into electrical energy.

 Not incredibly efficient at this time.  Lack of sufficient battery storing sources  Cost  Aesthetics