PUBLICATIONS

• Impact of solar tracker and energy storage system on sizing of hybrid energy systems: A comparison between diesel/PV/PHS and diesel/PV/ FC

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Energy 

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Abstract 

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Design of renewable energy-based hybrid systems has become a challenging task especially for electrification to off-grid regions. In the design problem, it is important to economically investigate utilization of energy storage systems (ESSs) and solar tracker. This paper focuses on optimal size of hybrid energy systems which make use of different types of tracking systems. For this aim, two hybrid energy systems, diesel enerator/photovoltaic/pumped hydro storage (diesel/PV/PHS) and diesel generator/ photovoltaic/fuel cell (diesel/PV/FC), have been designed with respect to different tracking systems (fixed, single-axis and double axis). In order to find optimum design of the hybrid systems, two important objectives, total net present cost (TNPC) and reliability index expressed by loss of power supply probability (LPSP) are minimized in a multi-objective framework. With respect to complexity of this optimization problem, a multi-objective efficient approach is used to solve the problem. Simulation results show that compared to FC when PHS is employed as energy storage system, TNPC of the hybrid system decreases. Moreover, using a solar tracker in diesel/PV/PHS is not cost-effective in comparison with fixed PV panels.

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• Daily performance optimization of a grid-connected hybrid system composed of photovoltaic and pumped hydro storage (PV/PHS)

 

Renewable Energy

 

Abstract

 

This paper presents a new methodology for minimizing daily operation cost of a grid-connected hybrid energy system composed of photovoltaic (PV) and pumped hydro storage (PHS) and evaluates the impact of water level on the system operation cost. For this aim, daily operation cost is defined as objective function and the value of power purchased from the grid at each hour is considered as decision variable (here 24 decision variables). The value of objective function is minimized subject to balance equation and reservoir water level. Owing to complexity of this optimization problem, a new variant of crow search algorithm (CSA), named differential CSA (CSAdif), has been developed to optimally utilize the hybrid system. Simulated results show that optimal combination of the components leads to considerable reduction of daily operation cost. Moreover, search capability of the proposed approach is more promising than that of the other studied techniques.

 

 

 

• Optimizing operation of a photovoltaic/diesel generator hybrid energy system with pumped hydro storage by a modified crow search algorithm

 

Journal of energy storage

 

Abstract

 

In a hybrid energy system composed of photovoltaic (PV), diesel generator and pumped hydro storage (PHS), to attain minimum fuel consumption, system operation should be optimized. This paper focuses on optimizing operation of a PV/diesel/PHS hybrid energy system by a modified crow search algorithm (CSA). For this aim, fuel consumption during the considered period is defined as the objective function. At deficit conditions (when PV generation is less than load demand), percent of deficit power which should be supplied by PHS is considered as decision variable. To effectively solve this difficult optimization problem, CSA with an adaptive chaotic awareness probability (CSAAc-AP) has been proposed. Simulated results reveal that the proposed CSAAc-AP produces more accurate and robust results than genetic algorithm (GA), particle swarm optimization (PSO) and original CSA. Moreover, optimal sharing of deficit power between diesel generator and PHS leads to having minimum operation cost.

 

 

 

• Optimizing operation of a photovoltaic/diesel generator/ Pumped Hydro Storage stand-alone hybrid energy system based on optimal fuel consumption

 

6th International Conference on Energy Technology and Management 2020.

 

Abstract

 

A Stand-alone hybrid system including photovoltaic cells, pumped hydro storage and diesel generator is optimally operated to reduce fossil fuel consumption. In this paper, when the energy produced by photovoltaic cells is greater than the demanded load, the excess energy is used to pump water from the well to the tank. On the other hand, when the power produced by photovoltaic cells is less than the demanded power, the deficit power is supplied either by the diesel generator or by releasing water from tank to hydro turbine. In fact, the percentage of load shortage power supplied by the turbine is considered as the decision variables of the problem, while the objective function is to minimize the amount of fossil fuel consumption by the diesel generator. For optimization, two methodologies: particle swarm optimization (PSO) and crow search (CSA) algorithms are used and the results of the two algorithms are compared.

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• A multi-objective approach for design of standalone PV/ Diesel Generator/ Pumped Hydro Storage hybrid system

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7th Annual Clean Energy Conference (ACEC 2021)

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Abstract

In this paper, the optimal sizing of hybrid energy system including photovoltaic cells, pumped hydro storage system and diesel generator is investigated to reduce Levelized cost of energy and fossil fuel pollution. For this aim, a two-axis solar cell tracking system is used and the results are compared with photovoltaic panels installed at a standard angle. The system operates in such a way that when the energy produced by the photovoltaic cells exceeds the demand for electricity, the excess energy produced is used to pump water from the well to the tank, and when the energy produced by the photovoltaic cells is less than the demand for electricity, the demanded load is supplied by Diesel generator or by releasing water from the tank to the water turbine. The number of system components including photovoltaic panels, diesel generators and pumped hydro storage are considered as problem decision variables, while the objective functions are minimized Levelized cost of energy and pollution. Multi-objective Crow Search Algorithm has been used to perform the optimization. The results show the importance of paying attention to the optimal measurement problem in hybrid systems.

 

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