Multi-criteria decision making (MCDM) methods are becoming increasingly popular in solving energy selection problems because these problems involve multiple and often conflicting criteria. This paper presents comparative analysis of ranking renewable energy sources (RES) for electricity generation in Taiwan using four MCDM methods – WSM, VIKOR, TOPSIS, and ELECTRE. The Shannon entropy weight method is used to assess the importance of each criterion for the ranking of RES. After that, four MCDM methods are utilized for quantitative evaluation to rank all available RE alternatives. From the weights estimation results, efficiency is the first priority in all evaluation criteria, followed by job creation, operation, and maintenance cost. The purpose of this study is to rank the priorities of various RES and propose recommendations for Taiwan’s RE development. The ranking results show that hydro is the best alternative in Taiwan, followed by solar, wind, biomass and geothermal. Furthermore, sensitivity analysis of the weights was conducted considering the ranking results heavily depend on the criteria weight. The results of sensitivity analysis indicated that when financial or technical aspects are focused upon, hydropower is the best RES because its technology is the most mature and the cost is the lowest in Taiwan. In addition, from an environmental perspective, wind energy is the best choice, and from the social perspective, solar PV is the best choice. The findings of this study can provide useful information to energy decision makers and serve as a reference for Taiwan’s energy policy.

Introduction

Energy plays an important role in a country’s economic development and it is a crucial factor in human life [1]. However, high consumption of fossil fuels leads to serious environmental problems, such as increasing greenhouse gas (GHG) emissions, which has led to global warming and climate change [2]. Most countries are actively developing renewable energy (RE) or sustainable energy to cope with environment crises [3–۶]. From the negotiation of the Kyoto Protocol in 1997 to the Paris Climate Change Conference in the end of 2015, many countries are strongly aware of the enormous threat of climate change and are devoted to carbon reduction and green economy development. Therefore, the transition from fossil sources to clean energy is an important issue for many countries. Taiwan has almost no energy sources of its own, with nearly 98% of its energy consumption depending on imports, and almost all fossil fuels coming from turbulent areas such as the Middle East [7]. In order to overcome the challenges of energy security and reduction of GHG emissions, expanding the supply and utilization of RE and accelerating the development of the RE industry have become important energy policies for Taiwan [8]. Taiwan government has clearly defined RE development goals and promoted various regulations, incentives, and technology R&D to improve the development of RE. According to the statistical report from REN21 (Renewable Energy Policy Network for the 21st Century) in 2015, the installed capacity of RE is 1849 GW and the total investment is nearly 300 billion US dollar globally. The proportion of RE supply has reached 23.7% [9] and the average annual growth rate is 5.9%. In addition, International Renewable Energy Agency (IRENA) estimated that global RE employment increased by 5% and reached 8.1 million in 2015 [10]. IRENA also forecasts that RE will account for almost 40% of global energy by 2030 due to reduction in technical costs. RE is clean and inexhaustible energy that offers many benefits such as being free and plentiful compared to conventional fossil fuel energy. However, RE suffers from production and capacity limitations due to the variability of solar sunshine and wind power. In particular, the electric cost of RE is higher than that of fossil fuels today. Moreover, infrastructure management (IM) is an important issue of the RE development. In many cases, IM decisions involve uncertainty, multiple and conflicting criteria.