energy. It demands immediate attention especially in the third world countries, where only scarce resources are available for an enormous size of population. To transform a silicon cell wafer into a solar cell, it is subjected to a number of steps, the most prominent being. How To Make a Solar Car: This project shows the making of a simple solar car. It takes millions of years for the energy in the sun’s core to make its way to the solar surface, and then just a little over eight minutes to travel the 93 million miles to earth. One other problem with focusing collectors in general is due to temperature. Unfortunately, reality still lags behind theory and a 15% efficiency is not usually considered economical by most power companies, even if it is fine for toys and pocket calculators. The type of storage facility most often used for such large solar heaters is the heat-of-fusion storage unit, but other kinds (such as the packed bed or hot water tank) can be used as well. These passive collectors can take a few different forms. At night or during heavy cloud cover, for example, the amount of energy produced by the collector will be quite small. (A general analytical solution to the equation is possible using Lambert’s W function, but since Lambert’s W generally itself must be solved numerically this is a technicality. They are separated by an internal electromagnetic field as a consequence of the potential difference at the p-n junction. Solar energy is often used to directly heat a house or building. Photovoltaic cells, by their very nature, convert radiation to electricity. Today, efficiency values of small crystalline silicon cells in the laboratory can be as high as 25% under STC [54]. These two components are a collector and a storage unit. As front cover low-iron glass is used in order to minimize absorption. Figure (26): I-U curve of a crystalline silicon photovoltaic cell. More than 90% of today’s annual solar production is made from crystalline silicon (figure 10). It is due to this withdrawal of support that has left the impression that solar power cannot succeed without substantial subsidies. This layer has a valence band which is densed with electrons and a conduction band. They offer a high potential for cost reduction due to their low material requirement [52]. This would supply 2.4 kW to 12.1 billion people. Solar furnaces are examples of this type of collector. Photovoltaic cells are made of special materials calle… With this passive collector, the heat normally absorbed and wasted in the walls and roof is re-routed into the area that needs to be heated. The following investigations on PV system aspects implicitly assume the application of crystalline cells. They are mostly framed with aluminium for easier mounting; however, frameless glass-Tedler modules do exist. It is already importing 100 Megawatts of power from India and has negotiated with private companies renting plants to buy power at higher rates. [46] From this point, solar research had the momentum and funding it needed from fuel providers, electric utilities and other interested parties to make a real impact on the energy industry. Solar radiation, along with secondary solar-powered resources such as wind and wave power, hydroelectricity and biomass, account for most of the available renewable energy on earth. Offered by École Polytechnique. The interest in renewable energy has been revived over last few year, especially after global awareness regarding the ill effects of fossil fuel burning. Electricity for All” by the year 2020.Bangladesh is one of the most severely affected counties of the World due to climate change and global warming effects. In 1839 a French physicist first discovered the photovoltaic effect while experimenting with an electrolytic cell made up of two metal electrodes. Later on, in 1954 researchers at Bell Labs accidentally discovered that p-n junction diodes generated a voltage when the room lights were on. Like other stars, the sun is a big gas ball made up mostly of hydrogen and helium. All objects have this property to some extent, but only some objects (like walls) will be able to produce enough heat to make it worthwhile. In its pure state, crystalline silicon is a poor conductor, due to the fact that all of the electrons in the. The rest could be used to supply our energy needs. Simulate I-V characteristic of the device. The last major form of passive collector is the solar pond. Active solar techniques include the use of photovoltaic panels and solar thermal collectors to harness the energy. A solar cell is basically a p-n junction diode. A number of different solar cell technologies are currently applied or under development (Table 1). A solar cell is an electronic device which directly converts sunlight into electricity. Most of our other forms of electricity generation are at a lower efficiency than this. Unlike solar thermal energy which converts solar energy to heat, PV cells directly convert sunlight into Ned, constructed in 1999 by the South Australian Solar Car Consortium, can electricity. Where does all this energy go? Drive Test and RF Parameters of GrameenPhone, The Pros and Cons of In-House IT Solutions, Security in Wireless Sensor Network (WSN), Credit Risk Grading(CRG) in Southest Bank Limited (Part-3), The Role of Electricity Infrastructure in Reducing Greenhouse Gas Emissions by Smart Grid, Assignment on Solar Radiation and Solar Cell. But the helium atom weighs less than the four nuclei that combined to form it. In order to make PV easy to handle in practice, solar cells are assembled into PV modules. The focusing collectors by their very nature can create much higher temperatures and need more safeguards to protect their silicon components. The radiation that does reach the Earth is the indirect source of nearly every type of energy used today. Often if an entire building is heated by solar power, passive collectors are used in addition to one of the other two types. The module efficiency under STC is roughly situated between 11 and 15%. For power applications, photovoltaic modules are typically assembled in larger groups in order to provide the desired power rating at a specified DC voltage. Mechanical and optical properties are ensured by the physical structure, chosen for the particular module. Once silicon of the desired purity is obtained, it is then put together into ingots and then cut into wafers using a saw. A single crystalline wafer is in fact one single crystal. The various uses of solar energy are firstly presented before a short description of the principle of the direct solar photon conversion into electricity (PV). The first is in the fact that it is renewable; it is never going to run out. Electric cars that are partially powered by solar energy are available now, but it is unlikely that solar power will provide the world’s transportation costs in the near future. These tasks include transportation, heating, cooling, and the generation of electricity. cell is 13% to 17% which is just lower than the efficiency of monocrystalline solar cell. Also, the rate at which this market is expanding is encouraging – from 85 MW in 1995 to 1.1 GW globally in 2005. This growth lasted until the mid- 1950s when low-cost natural gas became the primary fuel for heating American homes. However, because the equation involves I on both sides in a transcendental function the equation has no general analytical solution. There, they may be used as building element, for example, for awnings or structural glazing. The solar cell development and research takes place in three stages: Step – 1 - Firstly optimization research is done mostly in small (< 1 cm 2 area) cells Step – 2 - Secondly there are modules which are second phase of solar cell development. Crystalline silicon cells are usually manufactured from silicon wafers. When the solar cell is exposed to sunlight, photons hit the electrons in the valence band and give them enough energy to migrate into the conduction band. A partial list of solar applications includes space heating and cooling through solar architecture, potable water via distillation and disinfection, day lighting, solar hot water, solar cooking, and high temperature process heat for industrial purposes. The electromagnetic radiation (including visible light, infra-red light, and ultra-violet radiation) streams out into space in all directions. In this case each one has only 3 outer orbit electrons, and when added to pure silicon, there is a hole in the structure where one silicon electron has, nothing to bond to and is free to move. Inside the module, the cells are connected in series and parallel by means of copper strips in order to achieve practically applicable voltage and current. The sun radiates more energy in one second than people have used since the beginning of time! Another 30 percent is used to evaporate water, which, lifted into the atmosphere, produce’s rain-fall. These are larger in size (around 25 - 100 cm 2). Simultaneously, the short-circuit current increases proportionally to the solar irradiance. These electrons are occupying a band of energy called. Typically. However, other semiconductor materials are also applied and several technologies are investigated [30]. When the electron holes come together at the P-n junction, voltage is generated. Table: Overview of the application solar-cell technologies. Sometimes the pool itself functions as the storage unit, and sometimes a packed bed is added to store the heat. As the primary element of construction of solar panels, silicon, is the second most common element on the planet, there is very little environmental disturbance caused by the creation of solar panels. Multicrystalline silicon cells are, Slightly cheaper, but have a somewhat lower efficiency. Solar PV Cell Development by Arhaam Mubarak MME201002 Research Assignment The silicon photovoltaic solar cell absorbs solar radiation or energy. Electron holes and electrons begin to move toward the P-N junction. When the solar cell is exposed to sunlight, photons hit the electrons in the valence band and give them enough energy to migrate into the conduction band. The rating varies with the size and efficiency of the applied solar cells and the number of parallel cell strings within a module. First generation cells consists of the established Silicone based cells which are highly represented in commercial production. All of this indicates that even with the most optimistic view of conservation programs, sustainable energy generation will have to increase if development is expected to continue at current rates. Also, the same year an important event occurred called the Cherry hill conference. For many years the PV industry have used scrap silicon from the IC industry, but the increase of PV demand has nearly exhausted this market. The Government of Bangladesh is actively engaged in energy crisis management. 2. With the solar pond, the whole purpose of the pond is to serve as an energy regulator for a building. Passive solar techniques include orienting a building to the Sun, selecting materials with favorable thermal mass or light dispersing properties, and designing spaces that naturally circulate air. Figure (24): Schematic representation of crystalline solar cell supplying a resistive load. A relatively new approach is the production of multicrystalline silicon wafer ribbons or sheets, saving the cost of wafering ingots and reducing the sawing losses. This application of solar power is less common than the two mentioned above, because of the cost of the large panels and storage system required to make it work. Whether or not a packed bed is used, some method of keeping the pool’s heat for longer than normal periods (like a cover) is generally employed to help keep the water at a warm temperature when it is not in use. Government of Bangladesh is working towards achieving “Power i.e. In addition, the uses solar energy is currently applied to will be noted. Together these two countries, with Japan’s sunshine program and Germany’s 100.000 solar roofs program along with several government subsidies account for a full 69% of the world market for PV as of 2005. Electrical Engineering Assignment Help will be an additional option for you that raise your knowledge in a suitable way. The passive collectors absorb radiation and convert it to heat naturally, without being designed and built to do so. This type of cell has yet to be field-tested. However, even without a solution it is physically instructive. There, a n-doped semiconductor contact collects the conduction-band electrons and drives them to the external … When the lead wires are connected, electricity is generated. First the “violet cell” was developed, having an improved short wavelength response leading 30% relative increase in efficiency over the most advanced silicon cells at that time. Nevertheless, they are not expected to replace wafer type silicon cells yet. Over 100 years ago in France, a scientist used heat from a solar collector to make steam to drive a steam engine. The solar water heater gained popularity at this time in Florida, California, and the Southwest. Due to the nature of solar energy, two components are required to have a functional solar energy generator. To harvest the solar energy, the most common way is to use solar panels. The main advantage of the thin films is the lower price they could achieve once set into a mass production scheme. Only a small part of the radiant energy produced by the Sun strikes the Earth. Unfortunately, at this scale, the production of solar energy would have some unpredictable negative environmental effects. A thorough literature review with regard to shadowing and the function of the bypass diodes is available in [56]. Solar energy also is absorbed by plants, the land, and the oceans. For p doped silicon boron is added and for n doped silicon phosphorus is added. From the equivalent circuit it is evident that the current produced by the solar cell is equal to that produced by the current source, minus that which flows through the diode, minus that which flows through the shunt resistor: The current through these elements is governed by the voltage across them: By the Shockley diode equation, the current diverted through the diode is: By Ohm’s law, the current diverted through the shunt resistor is: Substituting these into the first equation produces the characteristic equation of a solar cell, which relates solar cell parameters to the output current and voltage: An alternative derivation produces an equation similar in appearance, but with V on the left-hand side. It is a form of photoelectric cell, defined as a device whose electrical characteristics, such as current, voltage, or resistance, vary when exposed to light. He melted selenium into a thin sheet of on a metal substrate and pressed gold-leaf film as the top contact. It may seem strange, but one of the most common uses of solar energy today is cooling. As of 2005, for example, China accounted for almost 30% of global growth where the European community accounted for just 5%. These bands are separated by an energy gap. V p increases logarithmically with I s and thus illumination. The net effect is that of a pump moving heat from one area into another, and the first is accordingly cooled. When this material is used to make solar cells, so little of this material is required that a foreign material is needed to physically support the cells. Everything from changes in local rain conditions to another Ice Age has been predicted as a result of producing solar energy on this scale. The Power Division made recommendation such as ceasing gas supply to gas-fired power plants after 2012 to conserve gas reserves for domestic use. Due to this absorbed energy, the phenomena of photovoltaic occurs and electrons are liberated and produce the external DC current. The collector simply collects the radiation that falls on it and converts a fraction of it to other forms of energy (either electricity and heat or heat alone). The efficiency of polycrystalline solar Sub: Solar Engineering Assignment No: 01 Name: Sri Dipanka Saikia (ENE17026) Topic: Different Solar Cell Properties and Characteristics. The smallest entity within a PV system is a solar cell. With swimming pools, the desired result is a warm pool. MPP stands for maximum power point and indicates the point on the I-U curve where the generated power reaches its maximum. Solar cars depend on PV cells to convert sunlight into electricity to drive electric motors. Also shown, on the right, is the schematic representation of a solar cell for use in circuit diagrams. Hope for bulk solar electricity should not be abandoned, however, for recent scientific advances have created a solar cell with an efficiency of 28.2% efficiency in the laboratory. Therefore, thicker wafers have to be made when working with crystalline technologies and, because of the size, higher quality material has to be used because of the longer paths the high-energy electrons have to travel before reaching the external circuit. In standard modules, the back side is usually covered by the aluminium- Tedler layer. The wafers are sawn out of single or multicrystalline silicon ingots by means of wire saws. Solar energy is quite simply the energy produced directly by the sun and collected elsewhere, normally the Earth. Solar energy can be harnessed using Solar Cells. Figure 11.24 shows graph for V p versus light intensity.. 11.8.2 Photovoltaic (PV) Cell/Solar Cells. Energy is the source of growth and the mover for economic and social development of a nation and its people. Among the renewable resources the solar power has the capacity of more potential. Only a small portion of the energy radiated by the sun into space strikes the earth, one part in two billion. Solar cell, any device that directly converts the energy of light into electrical energy through the photovoltaic effect. Frameless modules are called laminates. Solar energy’s uses are limited only by human ingenuity. comes from the electron’s negative charge. People use energy for many things, but a few general tasks consume most of the energy. Solar heating requires almost no energy transformation, so it has a very high efficiency. In today’s climate of growing energy needs and increasing environmental concern, alternatives to the use of non-renewable and polluting fossil fuels have to be investigated. As soon as the solar cell is exposed to sunlight, the solar energy which is present in the form of light photons is absorbed by semi conductor materials. Within a year they had produced a 6% efficient silicon p-n junction solar cell. A solar cell (also known as a photovoltaic cell or PV cell) is defined as an electrical device that converts light energy into electrical energy through the photovoltaic effect. The solar cells are generally made up of semiconductor materials which behave in a special way on exposure to sun light and give off electrons which is used for the flow of electricity. Solar cells are classified into three generations indicating the order of which each became important. Of the main types of energy usage, the least suited to solar power is transportation. the valence band. The interconnected cells are embedded between EVA (ethyl vinyl acetate) sheets or in cast resin in order to protect them from mechanical stress. 1. Every day enough energy strikes the United States to supply the nation’s energy needs for one and a half years! The parameter efficiency mainly shows the state of the art of different cell production technologies and serves as a benchmark for the achieved progress in solar-cell research. 1. Solar power has two big advantages over fossil fuels. Glass is applied when the back side of the modules is desired to be transparent at the cost of reduced cooling of the solar cells and higher weight of the module. This voltage is measured in units of electron volts (eV), thus in a material with 1eV band gap the voltage delivered by a single cell is around 0.7V. Explain what depletion region is and build in electric field? Rated values of current, voltage and power are generally given at the MPP under STC. Thin-film modules for power applications are not yet considerably cheaper than crystalline modules. Solar energy can be applied to all four of these tasks with different levels of success. N and p doped silicons are both created by adding something to the preproduction phase of a solar cell. are completely used or economically depleted. The additional energy they take in due to the correction of facing more than compensates for the energy needed to drive the extra machinery. At first glance this might seem surprising since neither Germany or Japan have a large amount of  sunlight, but their lack of fossil fuel sources combined with a national government committed to sustainable energy programs have enabled solar power to thrive. If it maintains its efficiency in the uncontrolled environment of the outside world, and if it does not have a tendency to break down, it will be economical for power companies to build solar power facilities after all. In order to yield the required DC voltage, modules are first connected in series into strings of modules. As its name implies, photovoltaic is a technology that converts light (photo) directly into electricity (voltaic). While large, relatively slow vehicles like ships could power themselves with large onboard solar panels, small constantly turning vehicles like cars could not. The heat remains in the sun and is instrumental in maintaining the thermonuclear reaction. The efficiency under STC is defined as the ratio of peak power to cell area times irradiance under STC. 1. The temperature of a gas is related to the pressure containing it, and all other things being held equal, the same gas under a lower pressure will have a lower temperature. The name “n-type”. The year 1973 was very important for PV technological advancement. The exceptions are geothermal energy, and nuclear fission and fusion. Even fossil fuels owe their origins to the sun; they were once living plants and animals whose life was dependent upon the sun. [2] Solar Night Light: Solar night lamp uses the solar energy to power up the night lamp. The only possible way a car could be completely solar powered would be through the use of battery that was charged by solar power at some stationary point and then later loaded into the car. Another major form of passive collector is thermos phonin walls and/or roof. When sun rays hit the silicon cell, electrons begin to move, creating a flow of electric current. This solar energy can be used for the other things beyond the heating method. In this process some “impurities” (e.g. Voltage is generated between both surface contacts and a connected load draws a current fig (23). ● P-type: Boron or gallium is added. A solar cell is simply a large photodiode operated in its photovoltaic mode. Glass-glass modules are mainly applied in building-integrated PV. View MME201002 RET Review assignment.pdf from MECHANICAL 3613 at Capital University of Science and Technology, Islamabad. In organic solar cells, the thin organic semiconducting layer is responsible for light absorption. Crystalline wafer-type silicon cells are expected to dominate the world market at least for the current data. The solar collectors that convert radiation into electricity can be either flat-plane collectors or focusing collectors, and the silicon components of these collectors are photovoltaic cells. The storage unit can hold the excess energy produced during the periods of maximum productivity, and release it when the productivity drops. Some matter is lost during nuclear fusion. The course provides an insight into the theory behind organic solar cells and describes the three main research areas within the field i.e. By adding several atoms of arsenic or phosphorous, enough electrons will be able to move, allowing an electrical current to flow through the material. The goal of the course is to give students awareness of the largest alternative form of energy and how organic / polymer solar cells can harvest this energy. The assignment may need a lot of understanding of the discipline, along with a great deal of your time, which you may not have, as you must study a lot for your exams too. Fraunhofer-Institute fur Solar Energiessysteme (FhG-ISE), Photovoltaic Systems, March, 1995 2. It can be tapped later by allowing the chemical to revert to its solid form. During this event a group of PV researchers and heads of US government scientific organizations met to evaluate the scientific merit and potential of photovoltaics. Incident lights free electrons. About 15 percent of the sun’s energy that hits the earth is reflected back into space. When the layer absorbs light, an excited state is created. Often these collector panels have automated machinery that keeps them facing the sun. C, N, As, B) are added to the material [48]. By the year 1960, several documents were written showing different solar cells built using different materials for the p-n junction, some key documents written by Prince, Loferski, Rappaport and Wysoski, Shockley and Queisser developed the fundamentals of p-n junction cell operation including the theoretical relationship between band gap, incident spectrum, temperature, thermodynamics and efficiency [46]. The course is an introduction to the photovoltaic (PV) applications in the general mix energetic context dominated by climate warming mitigation. They are about 0.3mm thick. When photons strike a PV cell, they may be reflected or absorbed (transmitted through the cell). At the same time the fossil fuel industry was experiencing problems with supply and cost, China’s economy was developing at incredible rates. These are currently used only in a few scattered areas. The civilization is dependent on electric power. 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