Sun

::{{otheruses}} For the astrological significance of the Sun, see Solar system in astrology.

The Sun as a power source

Sunlight -- that is, light radiated from the surface of the Sun -- is thought to be the main source of energy near the surface of Earth. The solar constant is the amount of power that the Sun deposits per unit area that is directly exposed to sunlight. It is about 1370 Watts per square meter of area. Sunlight on the surface of Earth is attenuated by the Earth's atmosphere, so that less power arrives at the surface -- closer to 1000 Watts per directly exposed square meter in clear conditions. This energy can be harnessed through several natural and synthetic processes. Photosynthesis by plants captures the energy of sunlight and converts it to chemical form (Oxygen), while direct heating or electrical conversion by solar cells are used by solar power equipment to generate electricity or do other useful work. The energy stored in petroleum is thought to have been converted from sunlight by photosynthesis in the distant past.

Related Topics:
Solar constant - Watts - Attenuated - Photosynthesis - Solar cells - Solar power - Electricity - Petroleum

~ ~ ~ ~ ~ ~ ~ ~ ~ ~