Transient simulation and 4E Analyses of a hybrid renewable energy system for an educational building

Document Type : Research Paper


1 Faculty of Mechanical Engineering, Semnan University, 35131-19111 Semnan, Iran

2 School of Mechanical Engineering, College of Engineering, University of Tehran, 11155-4563 Tehran, Iran



In this research, an integrated fossil-solar energy system has been designed, modeled, and optimized to supply the required loads of a six-story educational building in Tehran. The three heating, cooling, and electrical loads of the building are extracted in an hourly dynamic pattern for one year. System modeling was performed using a developed code in MATLAB software, and the genetic algorithm was used for two and three objective optimizations. The results show that with the two objectives of exergy efficiency and pollution, 68 rows of PVT panels and a solar collector with an area of ​​6.25m2 should be used. In this case, the maximum use of solar energy to supply 1945.9MWh heat and 484.5MWh electricity occurred during a year. Also, the highest amount of purchased electricity from the grid is 501.9MWh when the exergy efficiency and cost rate are considered as objective functions. In the three-objective optimization, the best system has an exergy efficiency of 50.21%. The CO2 emission and total cost rate are 7.1$/h and 301g/kWh, respectively. In this case, about 583.06 kWh of the heating load is supplied annually by 20 rows of PVT and a solar collector which has an area of 5.27m2. Photovoltaic panels generate 144.1MWh of the system's required electricity. The electricity sold to the grid in this scenario is 55.05MWh. Also, the system has purchased 204.2MWh of electricity from the grid annually. This means that the system should buy electricity from the grid most of the time each year.


Main Subjects

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