The Dilemma of the European Integration Principle—Ensuring Energy Independence of the European Union

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In this paper, the authors examine the current energy context and the impact of renewable energy sources on the transportation and domestic consumption sectors. The issues that need to be explained after the review of the paper are given below.

1- Please provide detailed information about the database used. Which parameters does it contain? What do the parameters characterize?

2- The purpose of using the OLS method should be clearly stated. 

3- Please give detailed information about the ARIMA model and other models used.

4- This study is not an empirical study. Instead, it is a research using data analysis and econometric methods. Therefore, the accuracy of the results obtained should be discussed.

5- When presenting the model results (Table 2) in the manuscript, please compare them with similar studies in the literature.

Comments on the Quality of English Language

There are minor grammatical errors in the English language.

Author Response

Dear Reviewer #1,

 

We extend our sincere appreciation for the constructive feedback you have provided. Your insightful comments have been instrumental in identifying areas for enhancement in our manuscript.

In light of your valuable suggestions, we are confident that our work can be significantly improved. Please find below our response:

 

Point 1: In this paper, the authors examine the current energy context and the impact of renewable energy sources on the transportation and domestic consumption sectors. The issues that need to be explained after the review of the paper are given below.

Please provide detailed information about the database used. Which parameters does it contain? What do the parameters characterize?

 

Response: LINES:  464-653

We added: “This research adopts a cascading methodology, employing a range of statistical and econometric tools to address the dilemma surrounding the European Union’s integration principle and the imperative for the member states to achieve energy dependence. The heightened significance of energy dependence, particularly in the context of recent geopolitical disruptions, has prompted the European Commission's proactive data collection on energy mix and import reliance. The database underpinning the study originates from the European Commission’s 2022 report on this critical subject [28]. Be-ginning with the central variable of import dependence, data collection extends to encompass gross available energy, elucidated through the lens of the energy mix.

Renewable energy sources in final energy consumption garnered particular attention, along with a close examination of electricity pricing across Europe. The pricing dynamics were explicated in relation to electricity production, energy flow, heating days, and the utilization of renewable energy. The selection of variables was steered by the formidable challenges the EU faces in the energy domain, including import dependence and the escalating trend of energy price volatility [29].

The database structure used in this study is organized to facilitate the analysis of energy-related parameters within the European Union. It encompasses several key tables, each containing specific attributes vital to the research objectives. These attributes include information on energy sources, consumption patterns, economic indicators, and other relevant variables. Its architecture allows for the systematic retrieval and manipulation of data to conduct comprehensive analyses. The central concern focuses on import dependence, serving as the primary endogenous variable of the study. This table includes entries related to net imports, gross available energy, and the derived indicator of energy dependence. Additionally, the dataset extends to incorporate detailed information on the energy mix, encompassing various fuel types such as gas, oil, coal, nuclear, and renewable sources. These components collectively contribute to the overall energy landscape within the EU.

Renewable energy sources, a critical aspect of the study, receive special attention. The database includes attributes pertaining to their utilization in both transportation and household electricity consumption. Furthermore, emphasis is placed on understanding the pricing dynamics of electricity in the European context. This involves variables related to electricity production, energy flow, days requiring heating, and the use of renewable energy sources in the energy production process.”

 

Point 2: The purpose of using the OLS method should be clearly stated.

Response: LINES:  723-728; 975-978

We added: ”The reason of deploying OLS was motivated by its suitability for the dataset, which exhibits linear relationships between the variables of interest. Additionally, OLS is a widely accepted and well-understood method for estimating linear models, making it an ap-propriate choice for research objectives. By utilizing OLS, the authors aim to provide robust and interpretable insights into the relationships between the independent and dependent variables. Thus, the linear model and the typical stochastic error term took the form:

And

“Furthermore, it is important to note that the assumptions of OLS, such as linearity, in-dependence of errors, and homoscedasticity, carefully assessed and found to be reasonably met in the dataset. This further justifies the choice of OLS as the preferred method for regression analysis in this context [52,53].”

 

Point 3: Please give detailed information about the ARIMA model and other models used.

Response: LINES:  959-970.

We added: “Therefore, by integrating the three components, the ARIMA model provided the flexi-bility needed to model time series patterns. This approach was particularly apt for the research outcomes. Additionally, the interpretability of the ARIMA model was invaluable in conveying the findings effectively, ensuring clarity for analysis. By deploying it, the authors captured autocorrelation patterns within the data, and its ability to handle non-stationarity through differencing proved crucial in achieving accurate predictions. The incorporation of moving average effects allowed to account for short-term fluctuations, leading to more robust forecasts. These results demonstrate the effectiveness of the ARIMA model in addressing the unique characteristics of time series data. However, it is important to acknowledge that the choice of ARIMA was contingent on the specific nature of the dataset, and researchers should consider alternative models in cases where complex nonlinear relationships or multiple interacting variables are present [51].”

 

Point 4: This study is not an empirical study. Instead, it is research using data analysis and econometric methods. Therefore, the accuracy of the results obtained should be discussed.

Response: LINES:  1067-1116

We appreciate your insightful feedback and acknowledge the distinction between an empirical study and research utilizing data analysis and econometric methods. We concur that our study falls within the latter category, employing rigorous econometric techniques to analyze the dataset. In light of this, we recognize the critical importance of discussing the accuracy of the results obtained. To address this concern, we have incorporated a thorough discussion in the revised manuscript regarding the robustness and validity of our findings. Please find them at the specified lines and below:

 

“Also, the accuracy of data can be a potential limitation even including research that employs data analysis and econometric methods. In many cases, data may be subject to measurement errors, missing values, or other sources of imperfection. These discrepancies can introduce uncertainties and affect the reliability of the results. Additionally, the assumptions underlying the econometric models used may not always align perfectly with the real-world data. This can potentially lead to discrepancies between the model's pre-dictions and actual outcomes. Therefore, it is crucial to acknowledge that while we have taken steps to ensure data quality and rigor in our analysis, there may still be inherent limitations related to data accuracy. These limitations should be considered when interpreting the findings, the study. Firstly, while efforts were made to ensure data accuracy and reliability, inherent limitations or errors within the dataset may affect the validity of findings. Secondly, econometric models rely on assumptions about the underlying data and relationships, potentially introducing uncertainty. Additionally, controlling for all possible variables that influence the outcome of interest is challenging, and omitted variables may introduce bias. Moreover, the sample used in the analysis may not fully represent the broader population, potentially limiting the generalizability of the conclusions. Finally, there is a risk of overfitting if models become overly complex, potentially leading to less reliable predictions for new data. However, one of the advantages of conducting research based on the methodology described is the ability to apply rigorous econometric techniques to analyze the data. This approach allows for a systematic and quantitative examination of relationships, providing a robust foundation for drawing meaningful conclusions. By employing established methods, the authors can uncover underlying patterns, test hypotheses, and generate empirical evidence with a high degree of precision. This methodology also facilitates the replication of the study, allowing for validation and further exploration of the research findings. Additionally, the use of econometric methods enabled to quantify the magnitude and significance of various factors, enhancing the depth and clarity of our insights. Overall, this approach ensures a structured and evidence-based approach to addressing the research objectives, contributing to a comprehensive and reliable body of knowledge in the field. In the case of this study, the utilization of econometrics presents a distinct advantage. This methodological approach empowered the authors to systematically analyze the intricate dynamics of European energy independence within the framework of European integration. By employing rigorous econometric models, we can quantitatively examine the various factors influencing this crucial principle, offering a comprehensive understanding of its complexities. This meticulous approach not only advances the understanding of the energy independence dilemma but also enriches the discourse on European integration policies and strategies. Ultimately, the paper endeavors to provide valuable insights that can inform policy decisions and shape the future trajectory of European energy independence."

 

Point 5: When presenting the model results (Table 2) in the manuscript, please compare them with similar studies in the literature.

Response: LINES:  959-970; 1008-1038

We added:

“Table 2 presents the competing models; the choice being based on the classic criteria for fitting the econometric models and the criteria Aikake and Schwartz. Therefore, by integrating the three components, the ARIMA model provided the flexibility needed to model time series patterns. This approach was particularly apt for the research outcomes. Additionally, the interpretability of the ARIMA model was invaluable in conveying the findings effectively, ensuring clarity for analysis. By deploying it, the authors captured autocorrelation patterns within the data, and its ability to handle non-stationarity through differencing proved crucial in achieving accurate predictions. The incorporation of moving average effects allowed to account for short-term fluctuations, leading to more robust forecasts. These results demonstrate the effectiveness of the ARIMA model in addressing the unique characteristics of time series data. However, it is important to acknowledge that the choice of ARIMA was contingent on the specific nature of the dataset, and researchers should consider alternative models in cases where complex nonlinear relationships or multiple interacting variables are present [51].”

Also, we added:

“The manuscript provides a comprehensive analysis of the complexities surrounding the energy transition within the European Union. It underscores the multifaceted nature of this transition, emphasizing that achieving a seamless shift to a zero-carbon economy is likely unattainable. The authors aptly assert that energy transition efforts should not only focus on production but also on altering energy consumption habits, recognizing the risk of energy shortages if the energy market is not adequately regulated. This highlights the intricate balance required for a successful transition [34]. While the EU's energy policy measures are acknowledged as effective, the authors astutely point out that they may not be entirely sufficient for a comprehensive shift towards renewable resources. They advocate for a holistic approach, emphasizing the need for changes in both production and consumption patterns. Furthermore, the study highlights the positive impact of green investments, economic openness, and efficient public governance on the green economic growth of nations. This reflects not only economic expansion but also a reduction in pollution and a move towards a carbon-neutral economy [36–38]. A critical aspect raised is the necessity of establishing an appropriate scale for implementing the EU's energy policy based on integration and transition. The authors aptly acknowledge that differing attitudes among EU member countries, stemming from economic development discrepancies, may pose challenges. This is particularly evident in regional electricity infrastructure, which plays a critical role in achieving EU targets cost-effectively. Additionally, concerns regarding energy security and access to renewable energy sources underscore the nuanced approach required for a unified energy policy [39–42]. The study’s examination of energy dependence among EU member states provides valuable insights. It identifies Croatia, Slovenia, Austria, and Greece as having the highest levels of energy dependence, while Estonia, France, Malta, Luxembourg, Ireland, Spain, Denmark, Sweden, Cyprus and Netherland exhibit the lowest. This geographic distribution underscores the need for tailored strategies to address specific challenges faced by individual member states [34].”

We genuinely appreciate your expertise and input, which have been immensely beneficial in refining our study. Your suggestions have prompted us to re-evaluate and enhance our approach, ultimately strengthening the robustness of our findings.

 

Thank you once again for your invaluable feedback.

 

Thank you for your contribution of this manuscript.

Sincerely yours,

Authors

 

 

 

 

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The research carried out by the authors addresses an important problem for the European Union. The method used in the research has several necessary steps that the authors explained well. The results of the analyses were carried out and answer the research question.

Although at the end of the manuscript, the authors highlight the practical implications of the research contribution, they should discuss the differences that the research brought in relation to previous research contributions.

Furthermore, in the introduction, fourth paragraph, be careful when calling renewable energies sustainable. This is because the sustainability of an energy system requires much more than just the potential for reducing greenhouse gases. Renewable energy may be clean and green but not automatically sustainable.

On page 8, in the first paragraph, they are referring to figure 2 and not figure 4.

On page 8, line 323, the beginning of the paragraph was confusing, as it is not known whether the authors are referring to renewable energy or solely to solar energy (of course, later in the text, the authors make it more explicit that it is of solar energy, but it could be apparent from the beginning of the paragraph).

Author Response

Dear Reviewer #2,

 

We extend our sincere appreciation for the constructive feedback you have provided. Your insightful comments have been instrumental in identifying areas for enhancement in our manuscript.

In light of your valuable suggestions, we are confident that our work can be significantly improved. Please find below our response:

 

Point 1: The research carried out by the authors addresses an important problem for the European Union. The method used in the research has several necessary steps that the authors explained well. The results of the analyses were carried out and answer the research question.

Although at the end of the manuscript, the authors highlight the practical implications of the research contribution, they should discuss the differences that the research brought in relation to previous research contributions.

Response: LINES:  1008-1038

We added:

“The manuscript provides a comprehensive analysis of the complexities surrounding the energy transition within the European Union. It underscores the multifaceted nature of this transition, emphasizing that achieving a seamless shift to a zero-carbon economy is likely unattainable. The authors aptly assert that energy transition efforts should not only focus on production but also on altering energy consumption habits, recognizing the risk of energy shortages if the energy market is not adequately regulated. This highlights the intricate balance required for a successful transition [34]. While the EU's energy policy measures are acknowledged as effective, the authors astutely point out that they may not be entirely sufficient for a comprehensive shift towards renewable resources. They advocate for a holistic approach, emphasizing the need for changes in both production and consumption patterns. Furthermore, the study highlights the positive impact of green investments, economic openness, and efficient public governance on the green economic growth of nations. This reflects not only economic expansion but also a reduction in pollution and a move towards a carbon-neutral economy [36–38]. A critical aspect raised is the necessity of establishing an appropriate scale for implementing the EU's energy policy based on integration and transition. The authors aptly acknowledge that differing attitudes among EU member countries, stemming from economic development discrepancies, may pose challenges. This is particularly evident in regional electricity infrastructure, which plays a critical role in achieving EU targets cost-effectively. Additionally, concerns regarding energy security and access to renewable energy sources underscore the nuanced approach required for a unified energy policy [39–42]. The study’s examination of energy dependence among EU member states provides valuable insights. It identifies Croatia, Slovenia, Austria, and Greece as having the highest levels of energy dependence, while Estonia, France, Malta, Luxembourg, Ireland, Spain, Denmark, Sweden, Cyprus and Netherland exhibit the lowest. This geographic distribution underscores the need for tailored strategies to address specific challenges faced by individual member states [34].”

 

Point 2: Furthermore, in the introduction, fourth paragraph, be careful when calling renewable energies sustainable. This is because the sustainability of an energy system requires much more than just the potential for reducing greenhouse gases. Renewable energy may be clean and green but not automatically sustainable.

Response: LINES:  250-258.

Your insightful caution regarding the terminology of 'sustainability' in relation to renewable energies has been thoughtfully considered. This serves as a pertinent reminder that while renewable sources exhibit environmental friendliness, their true sustainability encompasses a broader spectrum beyond solely reducing greenhouse gas emissions. Hence, we reformulated the aim of the study: “The objective of this study was to scrutinize the energy landscape through an ex-amination of member states' dependence on energy imports within the European Union (EU). This investigation encompassed the utilization of renewable energy sources, considering their application in both transportation and household electricity supply. Employing a combination of statistical and econometric methodologies, we conducted a comprehensive analysis of the EU's energy composition, evaluating its impact on micro and macroeconomic dimensions. In other words, the contribution of this research lies in explaining the macro and micro implications of the EU energy market and the opportunities for development (solar energy in transport and household consumption).”

Also, we reformulated the fourth paragraph:

“However, the transition to new sustainable energy sources encounters barriers that can hinder and delay this process. Energies deemed sustainable, including solar and wind technologies, possess a drawback due to their reliance on atmospheric conditions, which limits their capacity to fully address the shift towards renewable energies [5]. The intermittent nature of these sources introduces volatility and, to a certain extent, un-predictable when it comes to forecasting [6]. Although energy from any source is vital in a modern society, and although access to it has considerably improved in recent decades, there are still about 3 billion people who have access to electricity (an essential form of energy) in a very small proportion compared to developed countries and more than 750 million people have no access to electricity at all [7]. Additionally, green energy sources like wind and solar necessitate exponentially larger land areas for the same capacity generation when compared to fossil fuels. [8]. This places substantial pressure on land use, impacting agriculture, biodiversity conservation, residential zoning, topographical considerations, visual aesthetics, and more [9]. Another challenge raised by the transition to green energy sources consists in the raw materials used and the recycling of waste in the fields associated with it. Manufacturers of wind turbines, photovoltaic panels, electric batteries, etc., rely on inputs from natural resources, rather than those from waste recycling. The management of waste from renewable resources is also not sufficiently developed [10].”

 

Point 3: On page 8, in the first paragraph, they are referring to figure 2 and not figure 4.

Response: LINE: 824

Thank you very much for your observation. We changed to Figure 2.

 

Point 4: On page 8, line 323, the beginning of the paragraph was confusing, as it is not known whether the authors are referring to renewable energy or solely to solar energy (of course, later in the text, the authors make it more explicit that it is of solar energy, but it could be apparent from the beginning of the paragraph).

Response: LINE:  841.

We changed tis or energy to be more explicit. Thank you for the suggestion!

 

We genuinely appreciate your expertise and input, which have been immensely beneficial in refining our study. Your suggestions have prompted us to re-evaluate and enhance our approach, ultimately strengthening the robustness of our findings.

 

Thank you once again for your invaluable feedback.

 

Thank you for your contribution of this manuscript.

Sincerely yours,

Authors

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The aim of the paper was to approach the energy context from the perspective of the dependence on energy imports of the member states of the European Union (hereinafter referred to as the EU), by focusing on renewable energy sources used both in the field of transport and from the point of view of the electricity needed by household consumers. The article has an interesting approach, with interesting and important results, however there are some issues that authors must correct:

 - The abstract needs to be better structured and make the objective of the article clearer.

- The introduction is a weakness of the article and needs to provide a more adequate presentation of the themes and concepts worked on in the research. Furthermore, for the future of energy there are other works that can be cited as: https://doi.org/10.1016/j.renene.2019.08.092 , https://doi.org/10.1002/er.8094 , https://doi.org/10.1016/j.rser.2010.01.020

- Another important point to be improved in the introduction is the presentation of the contributions of the research.

- The literature review section needs to be expanded. Furthermore, the authors made a collection of references that are not connected and require work to make the text a more pleasant reading sequence for the reader.

- What is the existing data structure in the database used? What attributes were considered and what is the modeling of the data and variables?

- The authors present a series of equations throughout the methodology. What does each of them mean? What variables make up each equation? What were they used for? Follow the example of how equation 14 was explained.

- When discussing results, it is necessary to highlight a comparison with previous studies on similar topics.

Author Response

Dear Reviewer #3,

 

We extend our sincere appreciation for the constructive feedback you have provided. Your insightful comments have been instrumental in identifying areas for enhancement in our manuscript.

In light of your valuable suggestions, we are confident that our work can be significantly improved. Please find below our response:

 

Point 1: The aim of the paper was to approach the energy context from the perspective of the dependence on energy imports of the member states of the European Union (hereinafter referred to as the EU), by focusing on renewable energy sources used both in the field of transport and from the point of view of the electricity needed by household consumers. The article has an interesting approach, with interesting and important results, however there are some issues that authors must correct:

The abstract needs to be better structured and make the objective of the article clearer.

 

Response: LINES:  10-24.

We reformulated the entire abstract to highlight the objective of the paper in a better manner. Thank you for suggestion!

“The European Union’s energy policy confronts the intricate challenge of achieving energy independence through integration and transition, necessitating a careful calibration of its implementation scale. Recognizing the heightened energy dependence represents a threat to the economic convergence and cohesion of the member states, the authors adopted a comprehensive approach to scrutinize the energy landscape. The study examines the orientation towards renewable energy sources, encompassing their utilization in both transportation and household electricity supply. Leveraging a combination of statistical and econometric methodologies, the researchers analyzed the EU’s energy composition, evaluating its far-reaching impact on both micro and macroeconomic dimensions. Beginning with the central endogenous variable of the study, dependence on imports, the research extends to the assessment of gross available energy. Through rigorous ex-amination, the authors underscored the pivotal role of renewable fuels in final energy consumption and demonstrated the influence of green energy sources on household consumption. This investigation, complemented by the section of the ARIMA model for electricity price modelling, not only elucidated dilemma but also presents renewable energy sources as a viable solution to cur-tail the European Union’s dependence on energy imports, even in their current underutilized state.

 

Point 2: - The introduction is a weakness of the article and needs to provide a more adequate presentation of the themes and concepts worked on in the research. Furthermore, for the future of energy there are other works that can be cited as: https://doi.org/10.1016/j.renene.2019.08.092 , https://doi.org/10.1002/er.8094 , https://doi.org/10.1016/j.rser.2010.01.020

Response: LINES:  243-274.

Your insightful caution regarding the introduction weakness led us to inserting new references.

We added:

“For instance, Smart Grid enabling technologies and applications that ”will provide, on long term, an economic benefits for authorities” [5] , or “cloud-based environments” Energy Cloud which is offering more flexibility and autonomy to users [6], but an efficient dis-semination program is needed beside R&D on energy sources [7].”

 

“However, the transition to new sustainable energy sources encounters barriers that can hinder and delay this process. Energies deemed to be sustainable, including solar and wind technologies, possess a drawback due to their reliance on atmospheric conditions, which limits their capacity to fully address the shift towards renewable energies [8]. The intermittent nature of these sources introduces volatility and, to a certain extent, unpredictability when it comes to forecasting [9]. Although energy from any source is vital in a modern society, and although access to it has considerably improved in recent decades, there are still about 3 billion people who have access to electricity (an essential form of energy) in a very small proportion compared to developed countries and more than 750 million people have no access to electricity at all [10].  Additionally, green energy sources like wind and solar necessitate exponentially larger land areas for the same capacity generation when compared to fossil fuels. [11]. This places substantial pressure on land use, impacting agriculture, biodiversity conservation, residential zoning, topographical considerations, visual aesthetics, and more [12]. Another challenge raised by the transition to green energy sources consists in the raw materials used and the recycling of waste in the fields associated with it. Manufacturers of wind turbines, photovoltaic panels, electric batteries, etc., rely on inputs from natural resources, rather than those from waste recycling. The management of waste from renewable resources is also not sufficiently developed [13].”

 

Point 3: - Another important point to be improved in the introduction is the presentation of the contributions of the research.

Response: LINES:  266-274.

Thank you very much for your observation. We reformulated the objective of the paper:

The objective of this study was to scrutinize the energy landscape through an ex-amination of member states' dependence on energy imports within the European Union (EU). This investigation encompassed the utilization of renewable energy sources, considering their application in both transportation and household electricity supply. Employing a combination of statistical and econometric methodologies, we conducted a comprehensive analysis of the EU's energy composition, evaluating its impact on micro and macroeconomic dimensions. In other words, the contribution of this research lies in explaining the macro and micro implications of the EU energy market and the opportunities for development (solar energy in transport and household consumption).”

Also, please see the conclusions.

 

Point 4: - The literature review section needs to be expanded. Furthermore, the authors made a collection of references that are not connected and require work to make the text a more pleasant reading sequence for the reader.

Response: LINES:  280-283; 364-366; 374-379; 389-395; 432-435; 438-459.

Thank you very much!

We expanded the literature review by adding:

“Energy markets have “an oligopolistic structure based on global geographic conditions, which necessitates the import of energy products.” The European Union is vulnerable from the point of view of energy, due to its dependence on imports (such as from the Russian Federation) [14].”

 

“A specialized analysis shows that the EU's response to the COVID-19 crisis has created a powerful financial and political leverage to accelerate the green transition. However, “the EU's energy transition is falling short in fully integrating biodiversity” [17].”

 

“The specialized literature shows that replacing imports with internal sources of renewable energy produces additional positive effects in terms of energy independence and security, but also in sustainable development [22].

At the same time, energy organizations also face a series of drastic environmental problems, heavily affected by the COVID-19 pandemic. The results of a study show that the key factors that help a sustainable organizational performance of energy companies are: “implementation of knowledge management practices, policy changes” and de-centralization [23].”

 

“The energy transition is a necessity, and this must be based on the use of renewable energy sources in the energy production process. However, to implement appropriate strategies, a series of analyzes is needed. At first glance, in the EU, we are talking about a great diversity of countries (for example: countries have:  different levels of economic development, different number of inhabitants with major differences between populations; various cultures and customs; geographical location) [26]. A general policy is likely to become very difficult to be applied by all EU countries.”

 

“Efforts towards energy transition aim at preventing the energy poverty among the citizens of the EU and inside the economy, but there is still the risk of energy shortages in the case of an inadequate restraint on the energy market, with negative consequences for societies, economies and the environment [34].”

 

“The development of the energy transition requires actions not only on production, but also on energy consumption habits [36]. Along with the green investments, economic openness and the efficiency of public governance proved to have a positive impact on the green economic growth of countries, which reflects the economic growth along the reduction of pollution and a carbon-neutral economy [37]. The green transition to an environmentally friendly economy also includes implementing policies and practices that reduce green-house gas emissions, promote energy efficiency, increase the use of renewable energy sources, and reduce waste and pollution [38]. The EU's energy policy based on integration and transition also requires establishing an appropriate scale for its implementation [39], all the more as there are differences in attitude between EU member countries, due to problems related to economic development (some regional electricity system infrastructures appear to be critical in achieving EU targets with low costs) [40],  energy security [41] , or simply in the access to some forms of renewable energy sources (countries in Southern Europe, such as Spain, Italy, and Greece, have a significant advantage having abundant sunlight most of the year, making solar photovoltaic installations productive and efficient; compared to the Central Western Europe countries, the capacity of wind and solar PV productivity is lower; on the other side, the more developed countries are more likely to invest in renewable energy infrastructure [42]). The need to limit gas consumption after the beginning of the war in the Ukraine forced countries to rethink their transition paths, but this did not always happen by investing in various new energy sources, but by returning to the previous ones, proven to be more polluting [43].”

 

Point 4: -What is the existing data structure in the database used? What attributes were considered and what is the modelling of the data and variables?

Response: LINES:  461-646

We added: “This research adopts a cascading methodology, employing a range of statistical and econometric tools to address the dilemma surrounding the European Union’s integration principle and the imperative for the member states to achieve energy dependence. The heightened significance of energy dependence, particularly in the context of recent geopolitical disruptions, has prompted the European Commission's proactive data collection on energy mix and import reliance. The database underpinning the study originates from the European Commission’s 2022 report on this critical subject [28]. Be-ginning with the central variable of import dependence, data collection extends to encompass gross available energy, elucidated through the lens of the energy mix.

Renewable energy sources in final energy consumption garnered particular attention, along with a close examination of electricity pricing across Europe. The pricing dynamics were explicated in relation to electricity production, energy flow, heating days, and the utilization of renewable energy. The selection of variables was steered by the formidable challenges the EU faces in the energy domain, including import dependence and the escalating trend of energy price volatility [29].

The database structure used in this study is organized to facilitate the analysis of energy-related parameters within the European Union. It encompasses several key tables, each containing specific attributes vital to the research objectives. These attributes include information on energy sources, consumption patterns, economic indicators, and other relevant variables. Its architecture allows for the systematic retrieval and manipulation of data to conduct comprehensive analyses. The central concern focuses on import dependence, serving as the primary endogenous variable of the study. This table includes entries related to net imports, gross available energy, and the derived indicator of energy dependence. Additionally, the dataset extends to incorporate detailed information on the energy mix, encompassing various fuel types such as gas, oil, coal, nuclear, and renewable sources. These components collectively contribute to the overall energy landscape within the EU.

Renewable energy sources, a critical aspect of the study, receive special attention. The database includes attributes pertaining to their utilization in both transportation and household electricity consumption. Furthermore, emphasis is placed on understanding the pricing dynamics of electricity in the European context. This involves variables related to electricity production, energy flow, days requiring heating, and the use of renewable energy sources in the energy production process.”

 

Point 4: - The authors present a series of equations throughout the methodology. What does each of them mean? What variables make up each equation? What were they used for? Follow the example of how equation 14 was explained.

Response: LINES:  667-674; 679-695; 784-792.

We added explanations for equations, where relevant:

 

“Equation (1) plays a crucial role in assessing the extent to which the European Union relies on energy imports. It computes the energy dependence on imports by considering the total energy imports (Imports), subtracting the energy exports (Exports), and then dividing the result by the gross available energy (Gross available energy). This calculation yields a percentage that indicates the proportion of energy needs met through imports. This equation serves as a foundational metric for understanding the EU's reliance on external energy sources, a pivotal factor in shaping energy policies and strategies.”

 

“Equation (2) introduces it, a fundamental tool for evaluating economic disparities in the context of energy dependence. The Gini coefficient measures the inequality among values in a given dataset, which in this case pertains to energy dependence. It considers observed values, calculates the absolute differences between them, and normalizes the result based on the mean value. The Gini coefficient thus provides valuable insights into the distribution of energy dependence across EU member states, shedding light on potential disparities that may warrant further examination.”

 

“Equation (14) is employed to investigate autocorrelation within the dataset. Specifically, it computes the k-order correlation coefficient (ρ_k), a statistical measure that assesses the relationship between variables at different time points. In this context, it helps discern any patterns or dependencies in the energy-related data over time. The equation involves calculating the product of differences between values at specific time intervals and then normalizing the result based on the number of observations (n) and the mean of the series. By employing this equation, researchers can gain valuable insights into the temporal dynamics of energy-related variables, which is crucial for making informed policy recommendations.”

 

Point 4: - When discussing results, it is necessary to highlight a comparison with previous studies on similar topics.

Response: LINES: 1001-1031.

Also, we added:

“The manuscript provides a comprehensive analysis of the complexities surrounding the energy transition within the European Union. It underscores the multifaceted nature of this transition, emphasizing that achieving a seamless shift to a zero-carbon economy is likely unattainable. The authors aptly assert that energy transition efforts should not only focus on production but also on altering energy consumption habits, recognizing the risk of energy shortages if the energy market is not adequately regulated. This highlights the intricate balance required for a successful transition [34]. While the EU's energy policy measures are acknowledged as effective, the authors astutely point out that they may not be entirely sufficient for a comprehensive shift towards renewable resources. They advocate for a holistic approach, emphasizing the need for changes in both production and consumption patterns. Furthermore, the study highlights the positive impact of green investments, economic openness, and efficient public governance on the green economic growth of nations. This reflects not only economic expansion but also a reduction in pollution and a move towards a carbon-neutral economy [36–38]. A critical aspect raised is the necessity of establishing an appropriate scale for implementing the EU's energy policy based on integration and transition. The authors aptly acknowledge that differing attitudes among EU member countries, stemming from economic development discrepancies, may pose challenges. This is particularly evident in regional electricity infrastructure, which plays a critical role in achieving EU targets cost-effectively. Additionally, concerns regarding energy security and access to renewable energy sources underscore the nuanced approach required for a unified energy policy [39–42]. The study’s examination of energy dependence among EU member states provides valuable insights. It identifies Croatia, Slovenia, Austria, and Greece as having the highest levels of energy dependence, while Estonia, France, Malta, Luxembourg, Ireland, Spain, Denmark, Sweden, Cyprus and Netherland exhibit the lowest. This geographic distribution underscores the need for tailored strategies to address specific challenges faced by individual member states [34].”

 

We genuinely appreciate your expertise and input, which have been immensely beneficial in refining our study. Your suggestions have prompted us to re-evaluate and enhance our approach, ultimately strengthening the robustness of our findings.

 

Thank you once again for your invaluable feedback.

 

Thank you for your contribution of this manuscript.

Sincerely yours,

Authors

 

 

 

 

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The authors satisfactorily addressed the suggestions of this reviewer.