Renewable Energy
      Renewable energy, is energy that 
       originates from a replenishable source.
      Renewable energy is important because 
       it does NOT require the existence of 
       limited resources, and because it does 
       not lead to significant pollution.
     Solar Energy
      The sun’s rays can 
       be harnessed for 
       the purposes of 
       heating and 
       electricity.
      Both passive and 
       active uses of 
       solar energy 
       occur.
     Solar Energy
      Passive solar heating refers to using 
       the sun’s energy for direct heating 
       purposes. This allows buildings to avoid 
       expending fossil fuels for the purpose of 
       heating and cooling.
      Since the sun’s energy is not constant 
       over time, these buildings need quality 
       insulation to maintain their 
       temperature.
      Solar Energy
      Buildings that use passive solar heating 
        are designed to take advantage of the 
        sun’s position in the sky.
        During summer, the sun takes a high arc 
         in the sky; these buildings have an 
         overhanging roof to help stay cool.
        During winter, the sun takes a low arc in 
         the sky; these buildings have large 
         windows to collect added sunlight.
     Solar Energy
      In the Northern Hemisphere, south-
       facing windows receive the most 
       sunlight, so these windows will be the 
       largest.
      These windows are also double-paned, 
       so they function as additional insulation 
       during nights.