Active solar system.
(2) Active solar system. An active solar system is based on the use of mechanically forced energy transfer, such as the use of fans or pumps to circulate solar generated energy, or thermal energy transfer, such as systems utilizing thermal siphon principles. Generally, this is accomplished through the use of equipment such as collectors (to absorb sunlight and create hot liquids or air), storage tanks (to store hot liquids), rockbeds (to store hot air), thermostats (to activate pumps or fans which circulate the hot liquids or air), and heat exchangers (to utilize hot liquids or air to heat air or water).