Investigation on maximum power extraction for a partially shaded photovoltaic array

Abstract

Tamil Nadu faced an energy crisis of 4,000 MW in 2012 along with the transmission line losses of 18%. Because of the depletion and price of fossil fuel, the State needs to depend only on renewable sources such as wind and solar. Though the power generation from wind is about 39%, its conversion efficiency is not remarkable or possible throughout the year. Hence, the solar utility is the only optimal solution for Tamil Nadu to reduce the gap between the generation and the demand, and this is made possible by harvesting the abundant solar potential available throughout the state. The unclear economics remains the biggest obstacle for the expansion of PV system. A survey on energy consumption on hourly basis has been conducted among 150 urban and 150 rural residents of Madurai District in Tamil Nadu based on the questionnaire prepared with the details of electrical appliances. The survey analysis has reflected the income-based discrimination towards electric power usage by three types of residents. The 2.1 KWp Photovoltaic (PV) system has been designed and the corresponding payback period for the stand-alone and grid connected systems is calculated. Using the Hybrid Optimization Model for Electric Renewables (HOMER), the feasibility of grid-connected PV has system corroborated the utilization of solar energy of about 54%. The minimum Net Present Costs (NPC) and Cost of Energy (COE) of Rs. 834/unit and Rs. 11.7/unit ($13.9/unit and $0.195/unit), respectively have been considered economical and environmental friendly for the grid connected system with respect to low emissions of carbon dioxide, sulphur dioxide and nitrogen dioxide of 771, 2.13, and 1.04 kgs per year. In the study area, dust deposition is the major factor, which degrades the performance of the PV system. The dust particles attenuate the incoming solar radiation and reduce surface transmittance (and#964;). It leads to partial shading, which causes fluctuation in the output of the PV system and leads to grid instability. newline