الفهرس 
System Component
Storage size calculationsOnly 14 pages are availabe for public view
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Abstract
This thesis considers the optimum design of a stand-alone photovoltaic (PV) system to drive a refrigerator. The optimality criterion is to obtain a design that results in minimum cost of generated kWh. The two parameters affecting the cost are, the PV array size and the battery storage size.
The main task of this thesis is to determine the relation between system reliability and system cost. The PV array and storage batteries. The cost of PV array during 24 years is relatively load while the battery cost is the main cost of the PV system. This is because the life time of PV array is 24 years. So, PV array cost speed only once. On the other hands, the batteries have life time of only three years. This means that the batteries cost are paid 8 times during the PV array life time. Since the major cost of PV stand-alone system is the cost of batteries so the reduction in system cost comes from the concept of reducing the storage size. However, reducing the battery size while decrease the system reliability. The optimum design of the system is compress between system cost and system reliability. In this thesis the relation between system cost and system reliability is studied in details. It is found that reliability of 99.3% is obtained at cost reduction of 34%.
It is shown that as PV array size increases, the battery size decreases to certain limit. The optimum design should satisfy the condition that, the State Of charge (SOC) of the battery on 1st of January is the same as that at the end of 31st of December. This means that the battery stored charge remains constant at the end of the year, i.e. the load energy is supplied by PV system. This research concentrates on the effect of battery storage system on both system reliability and system cost. This thesis showed how reliability and cost is affected by storage size. The results obtained in this research (based on detailed simulation program) showed that the cost of Kwh generated remains low till 99.3% reliability. The model considers solar irradiance in Cairo city (30o N) assuming 3 consecutive cloudy days during both December and January. Any increase of reliability over 99.3% increases the cost significantly. The model considered in this thesis is based on driving standard refrigerator consuming about 2 kwh/day. The effect of battery storage size on both system reliability and system cost is studied in details. The results obtained showed that a system with 99% reliability is significantly lower in cost than a system with 100% reliability i.e. sacrificing 0.2% reliability results in cost reduction 10%. And sacrificing 0.7% in reliability (i.e. 99.3% reliability) reduces the cost of generated kwh by 34%.