الفهرس 
Chapter 1Only 14 pages are availabe for public view
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Abstract
The world is continuously asking for energy. Annually the world is asking for
4.7x1020 J, and it might grow about 2% every year for the next 25 years.1 The need for
energy might just double within the next 30 years. 2 Energy isn’t just used in our daily life
but also in industry and economy.3 World is using fossil fuel (coal, oil, and natural gas) as
the main source of energy, but it faces two main problems; the first is its limitation and the
second is its environmental damage.3
The sun gives the Earth about 100,000 TW per m2 per year which is 10,000 times
more than what we need.4 This is the least radiation by the sun in South Africa. It might
reach 200,000 TW per m2 per year, if we had solar cells with efficiency only 15% we will
need just 250 km2 to cover the world supply.5 The world is asking for approximately 600
TW per year.6 Solar energy is our way to survive, it can be used indirectly as hydroelectric
power “through evaporating water” or biomass “through photosynthesis” and directly
“through photovoltaic and solar plants”, so among all renewable sources of energy, solar
has the vast potential.3.