Skip to main content Skip to navigation links

NFCRC Tutorial: Solar

previous link: nuclear.html next link: wind.html

Approximately 1.55 x 10l8 KW hours of solar energy reach the earth's outer atmosphere annually. Approximately a third of this energy is reflected back into space and some absorbed by the atmosphere while approximately half reaches the earth's surface. Actually, wind, waves, rivers and ocean thermal gradients are all the various forms of solar energy, as they exist in nature. The form that is being harnessed more and more in recent times is the photosynthetic radiation for direct use for heating or conversion into electricity using solar cells.

photo of solar panelsSolar energy accounted for 0.07 quadrillion Btu (or 0.074 x109 Giga Joules) or .075% of the total energy consumption in the U.S. in 1996.


1. Approximately, what percentage of the sun's rays actually reach the earth's surface?
a) a third of the sun's rays
b) half of the sun's rays
c) all of the sun's rays
d) none of the sun's rays

previous link: nuclear.html next link: wind.html