Solar energy can be broadly categorized as active or passive solar energy depending on how they are captured and utilized. In active solar energy special solar heating equipment is used to convert solar energy to heat energy whereas in passive solar energy the mechanical equipment is not present. Active solar include the use of mechanical equipment like photovoltaic cells, solar thermal collectors or pumps and fans to trap the solar energy. Passive solar technologies convert solar energy to heat energy without use of active mechanical systems. It is mainly the practice of using windows, walls, trees, building placement and other simple techniques to capture or deflect the sun for use. Passive solar heating is a great way to conserve energy and maximizing it’s utilization. An example of passive solar heating is what happens to your car on a hot summer day.