This study aimed to analyze the systematic risks of wind energy investments. Within this framework, E7 countries are included in the scope of the examination. A large literature review was carried out and 12 different systematic risk factors that could exist in wind energy investments were identified. The analysis process of the study consisted of two different stages. First, the specified risk criteria were weighted with the help of the interval type 2 (IT2) fuzzy decision-making trial and evaluation laboratory (DEMATEL) method. Second, E7 countries were ranked according to the risk management effectiveness in wind energy investments. In this process, the IT2 fuzzy Vlsekriterijumska Optimizacija I Kompromisno Resenje (VIKOR) approach was taken into consideration. The findings show that volatility in exchange rates and interest rates were the most important risks in wind energy investments. In addition, it was determined that China and Indonesia were the most successful countries in managing risks in wind energy investments. In contrast, India, Russia, and Turkey were determined to be the least successful. Additionally, the IT2 fuzzy technique for order preference by similarity to ideal solution (TOPSIS) method was applied as a robustness check of the extended VIKOR method. It was concluded that the ranking results of the IT2 fuzzy TOPSIS method were similar to the results of the IT2 fuzzy VIKOR. It can be understood that the proposed ranking method was consistent with the comparative analysis results. From this point of view, it was observed that countries should take measures regarding their exchange rate and interest rate risks in order to increase the efficiency in wind energy investments. In this context, companies should first ensure that they do not have a foreign exchange short position in their balance sheets by conducting an effective financial analysis. In addition, it is important to use financial derivatives to minimize the exchange rate and interest rate risks. Using these results, it will be possible to manage this risk by taking the reverse position for the existing foreign currency and interest risk. In this way, it will be possible to increase the efficiency of wind energy investments, which will contribute to the social and economic development of each respective country.

This study seeks to find the appropriate strategies necessary to make sustainable and effective hydrogen energy investments. Within this scope, nine different criteria are defined regarding social, managerial, and financial factors. A hesitant, interval-valued, intuitionistic fuzzy (IVIF) decision-making trial and evaluation laboratory (DEMATEL) methodology is considered to calculate the degree of importance of the criteria. Additionally, impact relation maps are also generated to visualize the causality relationship between the factors. The findings indicate that the technical dimension has the greatest importance in comparison to managerial and financial factors. Furthermore, it is also concluded that storage and logistics, research and development, and technological infrastructure are the most significant factors to be considered when defining hydrogen energy investment strategies. Hence, before investing in hydrogen energy, necessary actions should be taken to minimize the storage and logistic costs. Among them, building the production site close to the usage area will contribute significantly to this purpose. In this way, possible losses during the transportation of hydrogen can be minimized. Moreover, it is essential to identify the lowest-cost hydrogen storage method by carrying out the necessary research and development activities, thereby increasing the sustainability and effectiveness of hydrogen energy investment projects.

This study aims to analyze the factors that influence electricity prices. For this purpose, a hybrid multi-criteria decision-making (MCDM) model based on interval-valued intuitionistic hesitant fuzzy (IVIHF) sets is proposed. Firstly, a large literature review is carried out and 10 different factors that can affect electricity prices are determined. After that, IVIHF decision making trial and evaluation laboratory (DEMATEL) methodology is considered to find which factors are more significant in electricity prices. The finding shows that inflation rate and technological improvement are the most important criteria that affect electricity prices. Thus, the countries should consider expected future inflation rates to take necessary precautions to minimize volatility in electricity prices. Moreover, countries should follow current technologies regularly and make effective research and development to provide electricity with lower prices. In the second stage of the analysis, emerging 7 (E7) economies are ranked with respect to the performance related to the management of electricity price volatility. In this context, IVIHF VIšeKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) approach is considered. It is concluded that Russia and China are the most successful countries in keeping electricity prices away from volatility whereas India and Turkey get the latest order. Furthermore, a comparative evaluation is also implemented by considering IVIHF technique for order preference by similarity to ideal solution (TOPSIS) methodology to check the consistency of the analysis results. The results of both approaches are quite similar which gives information about the consistency of the ranking results. On the other hand, a sensitivity analysis is performed to ten different cases consecutively. It is determined that the ranking results are coherent by considering the changes in the criteria weights.

The aim of this study is to determine the factors affecting the renewable energy consumption in Turkey. In this context, firstly, similar studies in the literature have been examined. As a result of the investigation, 11 different variables have been identified that may affect the use of renewable energy. Annual data of the mentioned variables in the period of 1990-2018 are taken into consideration. On the other hand, MARS method is used in the analysis process of the study. As a result, it has been determined that renewable energy use increases when the population in the country goes up. As can be seen from here, with the increasing population, the demand for energy has also increased. As a result, renewable energy has started to be used more. In addition, it is also determined that the increase in natural gas prices leads to higher consumption of renewable energy. In the event that natural gas becomes more expensive, it is understood that people are turning to other alternatives. The loan amount in the country is another factor that has an impact on renewable energy consumption. In case the loan amount exceeds a certain rate, it is seen that these loans are concentrated on non-renewable energy sources. In addition, it has been determined that there is a negative relationship between carbon emissions in the country and renewable energy use. It can be understood that renewable energy usage can be increased mainly because of the obligatory reasons, such as higher demand for energy and natural gas prices increase. This indicates that no sufficient consciousness is formed in Turkey for renewable energy. Therefore, it is important to provide the necessary incentives such as tax advantage by the state to make renewable energy use more attractive.