Humans have been harnessing solar energy, radiant light and heat from the sun since ancient times utilizing a wide array of ever-evolving technologies. The Greeks were the first to use advanced solar architecture and urban planning methods and the Chinese with orienting their buildings toward the south to provide light and absorb warmth. The utilizing of evaporation ponds to extract salt from the ocean or sea water is believed to be one of the oldest solar applications known.
The basic concepts used in solar applications have remained consistent since it was first discovered.

A DIY Solar Clothes Dryer

Some common features of passive solar applications in architecture are relative orientation to the Sun, compact proportion (a low surface area to volume ratio), selective shading (overhangs) and selecting materials with favorable thermal mass or light dispersing properties, and designing spaces that naturally circulate air. In buildings, the air is circulated past a solar heated surface and through the building by convection were the less dense warm air is displaced by the denser cool air.

Deciduous trees and plants also have been promoted as a means of controlling solar heating and cooling, there is a balance between the benefits of summer shading and the corresponding loss of winter heating. In climates with large heating requirements, evergreen trees should not be planted on the southern side of a building because they will interfere with solar heating in winter months.

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