The main objective of this work is to design an optimal—efficient economic power renewable energy system that feeds the required electric load of a small scale brackish reverse osmosis desalination unit and a tourism motel located in Hurghada, Egypt. Four renewable energy power systems are presented in this paper to select the most optimum one of them. These suggested renewable energy systems are PV-wind hybrid system, stand-alone wind system, stand-alone photovoltaic system and PV-wind-fuel cell hybrid system. The sizing, optimization and economic estimation of the proposed systems were performed using HOMER software. HOMER solves the optimization problem to minimize the global cost and provides the optimum wind turbine, PV, battery and fuel cell ratings. In addition, a comparison between the four different suggested power system configurations is illustrated in details. PV-wind hybrid system realized the lowest net present cost and levelized cost of energy. Also, this system was able to provide energy approximately all the day. The battery state of charge varies between 83% and 99% and it was found that, the PV-wind hybrid system is more suitable than the others for the selected site and the suggested electrical load
Low temperature geothermal resources are located in many areas and represent a high potential energy resource. One of the most common technologies, efficient and to exploit this type of resource is the binary cycle technology. Organic Rankine Cycle (ORC) is one of the main types of binary cycles. Electricity generation from low enthalpy geothermal energy using ORC is a talented technology. This paper addresses the design of binary cycle power plant utilizing one of the low temperature geothermal resource of temperature 92˚C using four alternative working fluids: Butane, Isobutane, Pentane and 1,1,1,3,3-Pentafluoropropan (R245fa). Bir Nabi is the well under consideration which located in the Eastern desert, Egypt. Three operation parameters: geothermal temperature, reinjection temperature and geothermal flow rate are taken into consideration to analyze the performance of the power plant for different fluids. A performance analysis is conducted on ORC binary power plant using MATLAB programming to study the variation of output power and efficiency with the operation parameters. Also, the effect of these parameters on the area of ORC binary cycle power plant components; preheater, evaporator and condenser is presented. The geothermal resources temperatures are in the range of 90˚C to130˚C, the mass flow rate of the geothermal fluid ranges between 10 kg/s and 50 kg/s and reinjection temperature ranges from 30˚C to 70˚C. The results indicate that, the highest output power and plant efficiency are obtained with Pentane.
Greenhouses are used for the main purpose of improving the environmental conditions in which plants are grown. There are many parameters can affect the growing of plants inside greenhouse, such as air temperature and relative humidity. The adjustment of these parameters is achieved by selecting appropriate control actions. This work proposes a controlling technique for greenhouse indoor temperature and relative humidity. The proposed greenhouse cooling system temperature controller is designed to adjust the air volume flow rate in pad-fan cooling system to fix the greenhouse indoor temperature at 20?C and 70% relative humidity. The designed control technique is realized to ensure the required and continuous operation of the greenhouse. Moreover, this work present, a complete mathematical modeling and simulation of cooling system is introduced. In addition, a computer model based on MATLAB SIMULINK software has been used to predict the temperature and relative humidity profiles inside the greenhouse. The results are realized the requirements of the greenhouse cooling system environment
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