OPTIMAL SIZING OF GRID-CONNECTED HYBRID POWER SYSTEM IN QESHM ISLAND IN PERSIAN GOLF OF IRAN S.Ghaemi , S.M.Moghaddas-Tafreshi K.N.Toosi University of Technology, Tehran, Iran
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[email protected] Abstract This paper presents an optimized design of grid-connected multi sources hybrid power system includes sources like, photovoltaic array, Electrolyzer, Fuel cell, H2-Tank and grid electricity based on Genetic Algorithm (GA). In this work, grid electricity has been used to cover demand loads when renewable sources couldn't produce enough energy. For this approach, economic aspects such as interest rate, inflation, capital recovery factor, sinking found factor have been expressed for each power sources, and then an objective function with aim to minimizing of all system costs, has been clarified. A genetic algorithm approach is employed to obtain the best cost value of hybrid power system construction. Simulation results show this method calculates the electrification costs (capital cost, replacement costs, operation and maintenance cost) over a period of 20 years for a residential part of QESHM located in Persian Golf of IRAN. Keywords: Hybrid Power Systems, Renewable Energy Sources, Optimization, PV array, Electrolyzer, Fuel Cell, H2-Tank
• 1. PROPOSED STRUCTURE OF HYBRID POWER SYSTEM In this research, two intelligent algorithms have been developed for a grid-connected multi sources hybrid power system evaluation and cost optimization. One for obtaining the optimal size of PV arrays, Fuel Cell and Electrolyzer and another for optimal operation and find the best size of Hydrogen storage tank. The costs include capital cost, replacement cost, operation and maintenance cost. Then two objective functions with aim to minimizing of total costs have been considered. The considered hybrid power system in this paper is a grid-connected system, includes PV, Fuel Cell, Electrolyzer and hydrogen storage tank, shows is Fige. 1. DC BUS PV Array
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Fig. 1: Proposed Grid-connected Hybrid Power System
• 2. SIMULATION AND RESAULTS The simulation results for a residential building in Qeshm Island in Persian Golf have been presented. 12 profile of hourly solar radiation and 12 profile of hourly load consumption are important input of this project. Fig. 2 and Fig. 3 shows one profile of solar radiation and load consumption respectively, which is used in this paper. 400 350 300 250 200 the150 main
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Two scenarios are described in this paper as case I and case II and these simulation results shows that until using subsidy Electricity and according to the high cost of renewable units in IRAN, it is not economical to installed renewable power plant. Reducing the cost of renewable units to 60%, causes the cost of produced hydrogen is decreased and using described hybrid power system is much more economical than grid electricity. Fig. 4 shows the operation result when the price of stored hydrogen is less than grid electricity. Note that, The unit of stored hydrogen is represented in Kg.
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Hour Fig. 4: Scenario II, hybrid power system's operation results in September
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