Optimal site selection of wind power plants using geographic information systems and best worst method: A case study in İzmir

Abstract

As the world and technology evolve, energy has become an integral part of everyday life in both private and public sense. To sustain this need for energy two types of energy generation are being used; non-renewable and renewable. Non-renewable energy uses such as fossils, coal and natural gas. These types of fuels in essence are finite, causing global warming and pollution and therefore destructive to the environment. Alternative resources called renewables are taking over as energy sources. They are environmentally friendly and sustainable energy sources. Out of all the renewable energy sources such as solar, hydropower and geothermal, this study focuses on wind power. Wind energy is harvested by wind turbines which are part of wind power plants (WPP). The location selection for wind power plants is important in order to maximize the efficiency and keep environmental impact at a minimum. Study area was chosen as İzmir, Turkey's third most populous city which uses a large amount of electrical energy. Geographic Information Systems (GIS) emerged in the 1980s as a new information processing system offering unique capabilities of automating, managing and analyzing spatial data. Many criteria play a role in determining these locations as they affect how well and efficiently a WPP will perform and generate energy. In order to utilize GIS to solve site selection problem these certain criteria has been determined which are split into two models; exclusion and evaluation model. Literature is reviewed in order to accurately and correctly determine these criteria. The exclusion model includes criteria and locations that WPP cannot be built upon. The evaluation model includes criteria that affect the efficiency and cost of building the WPP. The evaluation model includes the following criteria; wind speed, elevation, slope, distance to roads and distance to power transmission lines. Multi-Criteria Decision Making is utilized to determine the best locations in İzmir. The general objective of Multi-Criteria Decision-Making (MCDM) is to assist the decision-maker (DM) in selecting the "best" alternative from the number of feasible choice alternatives under the presence of multiple choice criteria and diverse criterion alternatives. After reviewing the literature, the method for MCDM is determined to be Best Worst Method (BWM). Best Worst Method uses pairwise comparison in order to achieve results. It has more consistent results as a result of its well-structured pairwise comparison system. Then the optimal weights of the criteria for accurately determining the suitable locations for wind power plants were determined. Moreover, in order to test the sensitivity and robustness of the model developed, a sensitivity analysis is done based on the combination of the criterion weights by using GIS. With these analyses performed, it is focused on creating the model that supports decision-makers in decision-making for finding the optimal locations of wind power plants. The steps that are taken in order to achieve these results in this study are as follows: Definition of the problem / objective (determining the most suitable locations for wind power plants). Determining the method for suitability analysis and wind energy standards by literature review. Selecting the criteria for determining the optimal locations for wind power plants. Data collection, preparation and processing in the GIS environment. Determining which criteria fall into either the evaluation model orthe exclusion model. Preparing the exclusion map by processing the criteria within the exclusion model. Preparing best-to-others and others-to-worst matrices with the help of experts' opinions. Determining the criteria weights with their consistency ratios by expert valuation and input using BWM (Best Worst Method). Determining final criteria weights by taking the average of the calculated weights of experts' opinions. Using the Weighted Sum tool within the GIS software and generating the suitability map. Determining the suggested locations for wind power plants with respect to the results of the suitability analysis and representing it in the final suitability map. Conducting sensitivity analysis in GIS environment in order to test the sensitivity and integrity of the developed model. Evaluating the system that supports decision-makers in determining the optimal locations of wind power plants. Giving out opinions on results and suggestions with respect to the results of this study. GIS when combined with a powerful multi-criteria-decision-making method such as BWM in this study, it offers excellent visualization and analyzing capabilities. This improves decision-making process and the renewable energy sector when selecting suitable sites for wind power plants. This study offers a new perspective on site selection for WPP by using BWM as the MCDM method. With the help of this study and GIS, more effective utilization of resources and time can be achieved, impact and damage to the environment can be lessened.