الفهرس 
CHAPTER 1Only 14 pages are availabe for public view
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Abstract
Solar Energy is the energy received by the earth from the sun. This energy is in the form of solar radiation, which makes the production of solar electricity possible. Solar energy is used to provide electricity to homes, businesses, schools and universities. (4)
Solar radiation represents such an infinite source of energy for the Earth. The sun delivers 1.2 × 1014 kW energy on the Earth, which is about 10,000 times more than the present energy consumption. The energy that the Earth receives from the sun in just one hour is equal to the total amount of energy consumed by humans in one year.
As illustrated in (Figure : 1) solar radiation can be utilized in various forms. The direct utilization of solar radiation uses the energy of light (mostly in the visible wavelength region) or heat (infra-red wavelength region). Light is used for the photovoltaic (PV) solar power generation, which means the direct conversion of light into electricity in devices called solar cells, or production of photochemical hydrogen. Heat is used mostly as a water heater in solar collectors. Wind, hydroelectric and wave power generation can be considered examples of the indirect utilization of solar radiation. For example, mills for grinding grain, water pumping or electricity generation use energy of the wind. The energy carried by the flow of rivers, by water from reservoirs, or by tidal and wave motion is converted into the hydroelectric power using the turbines. The photosynthesis process creates biomass, which is used for the production of ethanol in case of sugar cane or maize, or for the production of biogas in case of organic household waste. The examples of the geothermal energy sources are geysers or terrestrial heat surfaces, such as steam and hot water, for heating applications. (3)
1.2.1 Solar Energy Advantages:
• Environmentally friendly.
• No noise, no moving parts.
• No emissions.
• No use of fuels and water.
• Minimal maintenance requirements.
• Long lifetime.
• Electricity is generated wherever there is light, solar or artificial.
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• PV operates even in cloudy weather conditions.
• Modular or ―custom-made‖ energy, can be designed for any application from watch to a multi-megawatt power plant.(3,4)
1.2.2 Solar Energy Disadvantages:
• PV cannot operate without light.
• High initial costs that overshadow the low maintenance costs and lack of fuel costs.
• Large area needed for large scale applications.
• PV generates direct current: special DC appliances or inverters are neededin off-grid applications energy storage is needed, such as batteries.(3,4)
1.3. Solar Cell:
The energy of solar radiation is directly utilized in mainly two forms :
i) Direct conversion into electricity that takes place in semiconductor devices called solar cells.
ii) Accumulation of heat in solar collectors.
Therefore, do not confuse solar cells with solar collectors. The direct conversion of solar radiation into electricity is often described as a photovoltaic (PV) energy conversion because it is based on the photovoltaic effect. In general, the photovoltaic effect means the generation of a potential difference at the junction of two different materials in response to visible or other radiation. The whole field of solar energy conversion into electricity is therefore denoted as the ―photovoltaics‖. (4)
Solar Cell (photovoltaic cell) is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect. It is a form of photoelectric cell which, when exposed to light, can generate and support an electric current without being attached to any external voltage source, but do require an external load for power consumption.
The term ”photovoltaic” comes from the Greek φῶς (phōs) meaning ”light”, and from ”volt”, the unit of electro-motive force, the volt, which in turn comes from the last name of the Italian physicist Alessandro Volta, inventor of the battery (electrochemical cell).
Photovoltaics (PV) is the field of technology and research related to the practical application of photovoltaic cells in producing electricity from light, though it is often used specifically to refer to the generation of electricity from sunlight. Cells can be described as photovoltaic even when the light source is not necessarily sunlight (lamplight, artificial light, etc.). In such cases the cell is sometimes used as a photo detector (for example infrared detectors), detecting light or other electromagnetic radiation near the visible range, or measuring light intensity The operation of a photovoltaic (PV) cell requires 3 basic attributes