Photovoltaic cells are used to convert the energy of the sun directly into electricity. Anyone could use photovoltaic cells to create energy; however, it does and can take up a large amount of space. The technology could be used in all areas, in rural and urban settings. Edmund Becquerel (a French physicist ) first acknowledged the photoelectric effect in 1839 when certain materials were producing small electric currents when exposed to light. Albert Einstein is responsible for enlightening us upon the topic of the photoelectric effect and the nature of light on which the photovoltaic technology is based.
The technology improvement of the PV cell makes the PV array more reliable. The PV generation systems have two major problems. One is the non linear characteristics of PV cell which makes the electrical power generated vary with solar irradiation and temperature and the other one is low conversion efficiency of solar energy into electrical power. The P-V and V-I curve of the solar cell consists of only one point called the maximum power point. The system is to be operated at this point to get the maximum efficiency and produces maximum output power.
E. Becquerel. Though, it was not until 1883 that the first solar cell was built by the scientist named Charles Fritts, who coated the selenium semiconductor with an extremely thin layer of gold in order to form the junctions. This device was only around 1% efficient. After Russian physicist Aleksandra Stoletov built the first solar cell based on the outer photoelectric effect which was discovered by Heinrich Hertz earlier in 1887. The photoelectric effect was also explained by Albert Einstein in 1905 for which he received the Nobel Prize in Physics in 1921.
An IR transmitter is simply a LED diode that emits lights in the infrared region (700nm – 1mm) of the electromagnetic spectrum due to recombination of electrons into holes in the semiconductor as current flows through. Such diodes are usually made of gallium arsenic, gallium Antimony or Indium phosphide. The IR receiver is simply a phototransistor. A phototransistor is a transistor, without a base lead, that uses light (in this case infrared light) rather than electricity to cause an electric current to flow from one side to the other, hence they are used to convert light signals into electric signals. They are usually made of silicon or Germanium (Ambroziak, 2010).
Parabolic dish is a point focus concentrator with shape of a circular parabolic (surface of revolution generated by a parabola around its axis). In the proposed design, parabolic dish with min 2.4m diameter. The concave face of the concentrator will be lined with a reflective material so that incoming solar radiations that are travelling along the axis can be collected and reflected to a point focus. It should be noted that the size of the receiver is quite smaller than the collector
Renewable energy is energy that is collected from renewable resources such as sunlight, water, wind, and geothermal heat. A common form of renewable energy is solar energy. Solar energy is radiant light and heat from the Sun that is harnessed by using technologies such as solar heating, photovoltaics, solar thermal energy, and more. The Sun releases pockets of energy called photons that travel from the Sun to the Earth in a matter of minutes. When photons hit a solar panel, they knock electrons lose from their atoms.
1. INTRODUCTION Solar Furnace is structures, which concentrate all the sunlight (solar radiation) fall on it to a point or a line to increase temperature. It contains mirror which act as collector or reflector, which are arrange in such a way that all the sunlight fall on it is concentrated at, focus the temperature at focus may reach up to 3500’c. This heat can be utilized to generate electricity, Melting of metal, Cooking of food Carry out many chemical reactions and used to heat any fuel. [1] 1.1Type of Solar Furnace: Solar Furnace is of different type based on the collector design and its application 1.1.1Parabolic dish In Parabolic Dish the collector at a fix point concentrates solar furnace the solar light.
The photovoltaic effect was first reported by Edmund Becquerel in 1839 when he observed that the action of light on a silver coated platinum electrode immersed in electrolyte produced an electric current. Forty years later the first solid state photovoltaic devices were constructed by workers investigating the recently discovered photoconductivity of selenium. In 1876 William Adams and Richard Day found that a photocurrent could be produced in a sample of selenium when contacted by two heated platinum contacts. The photovoltaic action of the selenium differed from its photoconductive action in that a current was produced spontaneously by the action of light. No external power supply was needed.
CHAPTER 3 PHOTOVOLTAIC SYSTEM AND WIND ENERGY SYSTEM 3.1 Photovoltaic system The photovoltaic system was invented by Edmund Becquerel in 1839. He introduced the fact that some certain materials have small amounts of electric current when they are exposed to sunlight. In 1905, Albert Einstein explained the nature of the light and the photoelectric effect which becomes the main principle for the photovoltaic technology. In 1954, Bell Laboratories first built photovoltaic module In photovoltaic system, one or more number of solar panels is connected to convert the light energy into electrical energy. It has many having more components which are photovoltaic modules, electrical connections and mechanical connections.
They are sometimes called photovoltaic cells because they use sunlight ("photo" comes from the Greek word for light) to make electricity (the word "voltaic" is a reference to electricity pioneer Alessandro Volta). Principle of Power Generation: The principle of power generation behind the solar cells consists of the utilization of the photovoltaic effect of semiconductors. When such a cell is exposed to light, electron-hole pairs are generated in proportion to the intensity of the light. Solar cells are made by bonding together p-type and n-type semi- conductors. The negatively charged electrons move to the n-type semi- conductor while the positively charged holes move to the p-type semiconductor.