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In this paper, a method to review the role of renewable energy as an energy producer in scheduling a problem unit commitment is presented. Today, renewable energy sources, due to the lack of environmental pollution, and consequently a very low marginal cost, have been receiving considerable attention in power systems. The correct management of the unit commitment (UC) is a controversial and important issue in the power production unit, which requires suitable scheduled hours to obtain a minimum cost. This study was conducted to investigate the presence of electric vehicles and photovoltaic sources in UC and their impact to reduce production costs and improve load profiles. To achieve the optimum solution, a meta-heuristic Cuckoo search algorithm with high convergence speed is used to solve the UC problem. An IEEE 10-unit test system is employed to investigate the impacts of PEVs and PV on generation scheduling. Since the PV system is associated with uncertainty, in this study, the Uncertainty problem has been modeled using an iterative algorithm randomly with the allocation of density functions that fits the solar radiation. So, the used stochastic Monte Carlo optimization algorithm is capable of handling uncertain outputs of solar power. The simulation results show the effectiveness of the proposed method in reducing production costs and improving load profiles. [ABSTRACT FROM AUTHOR]

An energy storage system (ESS) is a promising tool for improving the power system's technical and economical functionalities. This device possesses diverse applications in terms of system operation and planning. One of the main applications of the ESS in the power system operation, specially a large scale unit, is defined as load leveling. To this end, in the literature, various ESS models are integrated into two main power system operation frameworks, i.e., optimal power flow (OPF) and unit commitment (UC). But the question is that in which framework the obtained benefit from the load leveling by ESS is maximum and why. In other words, should ESS units schedule before generating unit commitment (UC) or after OPF and how. In this context, this paper performs three works. First, it proposes OPF and UC frameworks integrated with large scale ESS units. Second, the proposed models are implemented with identical parameters. Third, the obtained results are considered with respect to various outcomes, especially operation cost. This study is implemented on an IEEE 24 bus RTS system. The simulation results are analyzed and compared with respect to various parameters and relevant conclusions are drawn based on the results. [ABSTRACT FROM AUTHOR]