What is the difference between passive solar energy systems and active solar energy systems?

Answer 1

The difference between a passive solar energy system and and active solar energy system is how the energy is collected and distributed. In a passive solar energy system, the building itself is designed as a collector and the heat is distributed by natural means. In an active solar energy system, special collectors, storage tanks, and mechanical and electrical equipment (pumps and fans) are used to transport and distribute the heat energy.

Passive systems - convert sunlight into electricity, which is used to heat a hot-water tank. Active systems have tubes behind them filled with water from the household supply. The direct energy from the sun heats the water in the tubes.

Passive solar usually has no moving parts and the sun's energy is stored directly in whatever the sun is hitting such as a large mass or a room.

Active solar heating will usually involve the use of pumps to pump a fluid to solar collectors and then back to a distribution point where the solar energy collected is transferred to another heating system, such as a forced hot air system. Active solar is much more complicated.

Passive solar heating has no moving parts, but utilizes windows and the sun. The position of the house is very important.

Active solar heating uses solar panels to produce electricity for heating, or pumps to move water warmed by the sun.

Answer 2

Passive solar energy systems use building design elements to capture and retain sunlight for heating purposes without the need for mechanical or electrical components, while active solar energy systems use solar panels or thermal collectors to convert sunlight into usable energy with the help of pumps or fans. Essentially, passive systems rely on natural processes whereas active systems require additional technology to harness solar energy.