Electric Energy Advantages And Disadvantages

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1.1 OVERVIEW OF THE PROJECT Since fossil fuels are non-renewable and cause harm to the environment, there is a need of clean, non-polluting and renewable energy. Therefore an extensive method for generating electric energy has to be employed. One of such interesting method is by using photovoltaics which are noiseless, nonpolluting and requires very less maintenance. Even though there are many advantages of generating electric energy through photovoltaics, there are also problems associated with it. One of such problem is the low voltage of PV modules, which is not suitable for high voltage dc applications. Therefore to meet the application requirements number of PV modules should be connected in series. But the partial shading of PV modules…show more content…
The general V-I curve and power of PV cell is shown in Fig.2. Fig.2. Solar panel V-I characteristic and Power curve Due to the nonlinearity of the V-I curve; there is difficulty in extracting the maximum possible power from solar panel. The fig above shows two curves, one is the variation of current with respect to voltage and other is the power voltage curve. From the power curve one can locate the maximum power at which the solar panel operates. But due to the changing environmental conditions like temperature and irradiation, the point at which the maximum power is obtained will be deviated. So a system is required to continuously track the power curve and keep the operating point close to maxima. 1.3 PARTIAL SHADING PROBLEM The generation of electricity through photovoltaics is in demand as it is free from pollution and it is renewable energy source. However the problems associated with photovoltaics cannot be neglected. The environmental conditions such as temperature, dust, shadow caused by birds and buildings affects the electrical characteristics of solar panel. One of the main problems associated with solar panels is partial shading of PV modules which leads to the reduction of PV output power. If one or more PV modules are under partial shading, some of the PV module’s series strings are less illuminated. It means that partial shading of one module affect the rest of the module and the current of the less illuminated module flows across whole string. So the bypass diodes are connected across the PV module to shunt the current around
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