Assessing the efficiency of renewable energy policies: A DEA, machine learning, and panel data approach

This bibliometric study seeks to analyze the intellectual structure and development of green finance research over a nearly 30-year period. Using Scopus data, a comprehensive analysis of 1,487 English-language publications on green finance was conducted. The scope of the analysis spans the years from 1997 to 2024. The analysis investigates numerous facets of green finance scholarship, such as publication and citation trends, influential works, authorship networks, geographic concentrations, conceptual links, and developmental phases. Since 2015, the number of publications and citations has increased significantly, indicating a significant rise in academic and industry interest. China is the leader in terms of research output and influence, demonstrating its dominance in the field. However, it is essential to note that other Asia-Pacific countries, such as Japan and Malaysia, have also made significant contributions to the field. Public policies, government initiatives, and the participation of the private sector are crucial to accelerating green investments and promoting sustainability, as evidenced by numerous citations to scholarly works on the subject. The study investigates a number of prospective future research avenues, including green bonds, green credit policies, green investment, green financial regulation, and green financial technology applications. Despite its heavy reliance on English-language Scopus sources, this quantitative longitudinal mapping provides valuable insights into the emergence and evolution of green finance as a significant multidisciplinary research field.

Acknowledgment
It is essential to express gratitude to all those who contributed to the success of this study, particularly those at the Ho Chi Minh University of Banking, Vietnam.

In an environment where public funding is insufficient to meet international climate and energy goals, feed-in tariffs serve as an essential mechanism to mitigate investment risk and foster the participation of insurance companies as institutional investors in the renewable energy sector. This study aims to investigate whether feed-in tariff policies enhance the evolving effect of insurance sector development on renewable energy consumption across countries and over time. Given that both financial sector capacity and renewable energy transitions are dynamic processes, the analysis explicitly applies econometric techniques designed to capture temporal changes and investment inertia. Using panel data econometric techniques, including fixed effects models with cluster-robust standard errors and dynamic panel estimation (Arellano-Bond GMM), the analysis covers 64 countries from 2000 to 2020. The results reveal that greater insurance sector assets positively correlate with higher renewable energy consumption, with a coefficient of 0.143 (p < 0.01) in the fixed effects model. Still, the strength and significance of this relationship are notably enhanced when feed-in tariffs are in place, as shown by a positive and statistically significant interaction term (coefficient 0.051, p < 0.05) after adding time-fixed effects. The empirical results show that insurance companies can serve as critical institutional investors in the renewable energy sector. Still, their active participation critically depends on supportive policy frameworks, with the positive association between insurance company assets and renewable energy consumption becoming significant, particularly in countries with feed-in tariff schemes.

Acknowledgment
This study was prepared as part of the project IZURZ1_224119/1 (Swiss National Science Foundation) and the National Scholarship Programme of the Slovak Republic.
The publication was funded by the European Union grant “NextGenerationEU through the Recovery and Resilience Plan for Slovakia” (No. 09I03-03-V01-00130) and project VEGA – 1/0392/23 “Changes in the approach to the creation of companies’ distribution management concepts influenced by the effects of social and economic crises caused by the global pandemic and increased security risks.”

Providing people with access to sustainable energy and overcoming energy poverty are essential tasks of the energy transition to a climate-neutral economy. The paper aims to examine the financial measures to alleviate energy poverty in Ukraine, such as the provision of energy subsidies and the financing of local programs to improve the energy efficiency of buildings through the Energy Efficiency Fund. Using statistical data of the International Energy Agency, Eurostat, the Ministry of Energy of Ukraine, and the State Statistics Service of Ukraine, the paper analyzes the state of energy poverty in Ukraine compared to EU countries. In the context of Ukraine’s intensifying energy and economic crises, the assessment of the fiscal cost of energy subsidies reflects a significant increase in an additional burden on the state budget. The fiscal cost of subsidies was assessed using the price-gap approach. The paper presents the results of energy modernization of buildings in Ukraine through the Energy Efficiency Fund. Implementation of energy modernization projects for buildings reduces energy costs and СО2 emissions, increases housing energy efficiency, and expands the possibilities of overcoming energy poverty. The application of the cost-benefit analysis method to sustainable housing renovation projects is demonstrated to more accurately assess energy and carbon impacts and to obtain financial support. The formulated proposals aim to raise awareness of power structures and support informed decision-making to overcome energy poverty and build a sustainable energy future for Ukraine.

Acknowledgment
This article presents the results of a study conducted as part of the scientific project “Formation of the foundations of nationally rooted stability and security of the economic development of Ukraine in the conditions of the hybrid “peace-war” system” (state registration number 0123U100965).