Application of fuzzy decision-making based on INSGA-II to designing
PV–wind hybrid system
H. Shayeghi a,b,n, Y. Hashemi a a Department of Electrical Engineering, University of Mohaghegh Ardabili, Ardabil, Iran b Centre of Excellence for Power System Automation and Operation, Department of Electrical Engineering, Iran University of Science and Technology, Tehran,
Iran a r t i c l e i n f o
Received 18 December 2014
Received in revised form 19 April 2015
Accepted 21 April 2015
Hybrid generation system
Improved non-dominated sorting genetic algorithm-II
Fuzzy decision-making a b s t r a c t
This paper addresses the attuned design of wind and photovoltaic (PV) hybrid generation system to supply office buildings. The main target of this design is to minimize the annualized cost of the hybrid system, environmental cost related to pollutant gas emissions avoided due to the use of the hybrid generation system, and index of loss of power supply probability. System costs consist of investment, replacement, operation, and maintenance cost of each component. The problem of design is formulated as a multi-objective optimization issue and solved by improved non-dominated sorting genetic algorithm-II (INSGA-II). The presented technique intends to offer the optimal number of system devices such that the economic and environmental profits achieved during the systems operational lifetime period are maximized. Optimizations of decision variables are the optimal number of photovoltaic modules, wind turbines, inverters, charge controllers, and storage batteries. A decision-making methodology based on fuzzy decision-making (FDM) is applied for finding the best compromise solution from the set of Pareto-optimal solutions obtained by INSGA-II technique. Two frameworks are considered for the design procedure of hybrid generation system. In the first framework, a twoobjective optimization problem is developed based on system cost and environmental cost. The second framework is formulated based on three objective functions: system cost; environmental cost; and reliability index. The proposed method has been conducted on four office buildings in city of Ardabil. The comparative analysis shows the efficiency of the proposed method. & 2015 Elsevier Ltd. All rights reserved. 1. Introduction
Considerable levels of demand for energy have become an increasing source of concern during the last few decades. This issue is because energy is necessary for both economic development and improving quality of life in all countries. Significant use of fossil fuels and other natural resources, on which humanity relies for their own survival and welfare, is the associated consequence of effects upon the environment, especially through damage to air, climate, water, land, and wildfire. The global climate destabilization underway is primarily due to human combustion of fossil fuels for energy and the resultant greenhouse gas (GHG) emissions. There is a large consensus among scientists that, if current behaviors continue in climate destabilization, the earth will reach a point of no return. The challenge of reducing atmospheric GHG like carbon dioxide emissions is significant for stabilizing the global climate. Because of the seriousness of the potential threat posed by global environmental change, there is an increasing stress upon traditional sources of energy against the backdrop of increasing global demand, which has caused the emergence of renewable sources of energy generation. Sustainable and renewable energy technologies such as solar PV and wind energy conversion systems are a solution to overcome the energy demands of societies while reducing the adverse anthropogenic effects of fossil fuels. Many of the governments have produced policies intended to procure and improve the cost-effectiveness of renewable energy target (RET) projects by suggesting financial incentives. To reach sustainable development, hybridizing energy becomes a crucial solution. Due to the problems related to transporting electricity in remote zones and its increasing cost, it would be more judicious to consider the use of PV–wind turbine hybrid systems in the areas where solar irradiation and wind are available. The hybrid system is composed of two parts: wind turbine and solar panels; it is considered to be an excellent solution compared to stand-alone single source photovoltaic or wind systems (Nikhil and Subhakar, 2013). To extract maximum energy, it is required to know the contribution of each source,
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Engineering Applications of Artificial Intelligence http://dx.doi.org/10.1016/j.engappai.2015.04.013 0952-1976/& 2015 Elsevier Ltd. All rights reserved. n Correspondence to: Department of Electrical Engineering, University of
Mohaghegh Ardabili, Daneshgah Street, P.O. Box 179, Ardabil, Iran.
Tel.: þ98 451 5517374; fax: þ98 451 5512904.
E-mail address: email@example.com (H. Shayeghi).
Engineering Applications of Artificial Intelligence 45 (2015) 1–17 since they change according to daytime, season, and year. Standalone hybrid systems can be implemented in rural or urban areas for many uses such as pumping, water desalination, lightening, and communications. Wind and solar systems are essentially intermittent and quite variable in their output. Also, they require high capital costs. Thus, power changes may be incurred, since both power sources are highly dependent on weather situation. To mitigate or even cancel out the fluctuations in hybrid systems, energy storage systems, such as storage batteries (SBs), can be implemented. SBs absorb the extra power and supply the deficit power in different operating conditions. On the other hand, there are various uncertainties in the operations of such hybrid systems; for example, equipment failures and stochastic/load variations.
Thus, because of the intermittent behavior of wind speed, solar irradiation, and some other issues, the most important challenge is design of such hybrid systems in the reliable supply of demand under varying weather states, considering operation and investment costs of the components.