Iryna Sotnyk

Households are responsible for more than one-third of global energy consumption and exert a significant environmental impact. Therefore, energy efficiency and renewable energy issues have been a top theme in the literature, with numerous studies examining different facets of residential power consumption, green energy transition, decarbonization, and energy conservation. Despite extensive attention, these research trends and frontiers remain largely uncharacterized and poorly understood. This study aims to provide clear insights into the evolution and latest trends of household energy efficiency and renewable energy studies, reveal significant contributing countries, institutions, and authors of published papers, as well as directions of international collaboration. The method of bibliometric analysis with two supporting instruments (the SciVal platform and Scopus “Analyze search results” tool) was used to investigate an array of 3,761 research items on renewable energy and 4,474 items on energy efficiency in homes formed from the Scopus database. The studied period includes papers published during 1978–2023. The systematic review indicated that the United States, the United Kingdom, and China are primarily contributing countries with strong international collaboration in this field. The top journals include Energy Policy, Energy Efficiency, Energies, and Sustainability, while highly cited researchers investigate environmental, economic, and social effects and management mechanisms for introducing innovative energy-efficient and renewable energy technologies in households like smart meters and grids or the Internet of Things. The research frontier might encompass emerging and pioneering studies on home decarbonization strategies, behavioral interventions, energy saving, prosumerism, and optimization of energy consumption.

Acknowledgment
The paper is prepared within the framework of the research project “Formation of economic mechanisms to increase energy efficiency and provide sustainable development of renewable energy in Ukraine’s households” (No. 0122U001233), funded by the National Research Foundation of Ukraine.

The recent surge in publications addressing household energy efficiency and renewable energy highlights their vital roles in managing national decarbonization and green power transition. The study aims to analyze the research trends in this field to comprehend their significance in shaping residential decarbonization changes. Bibliometric and visualization analyses are applied to bridge existing knowledge gaps by focusing on technology and managerial mechanisms for implementing energy efficiency and renewable energy concepts. Leveraging the Scopus database and VOSviewer 1.6.19 software, the study covers energy efficiency publications from 1978 to 2023 and renewable energy papers from 1984 to 2023. The study clusters academic articles in two ways: keyword co-occurrence and co-authorship analyses. The first one reveals the merging of renewable energy and energy efficiency studies, covering sustainable development, heating/cooling mechanisms, and emerging technology trends. While both topics share commonalities like smart grids and the Internet of Things, renewable energy clusters spotlight specific areas such as bioenergy and wind/solar power. Co-authorship analysis highlights a notable increase in countries considering research topics, reflecting growing international collaboration. Leading contributors include the United States, the United Kingdom, China, Germany, and India. This study equips scientists with a systematic understanding of the evolution and latest research trends in managing household energy efficiency and renewable energy transformations. It aids in identifying promising research directions, further advancing these crucial fields.

Acknowledgments
The publication was prepared in the framework of the research project “Formation of economic mechanisms to increase energy efficiency and provide sustainable development of renewable energy in Ukraine’s households” (No. 0122U001233), funded by the National Research Foundation of Ukraine.

Due to the full-scale war of Russia against Ukraine in 2022, extreme danger and vulnerability have caused changes in the social and economic stability of a person both on the individual and at the family level, in various social groups, as well as in territorial communities. Thus, the study aims to investigate the sources of social and economic resilience of Ukraine’s population during the war in the context of developing a social solidarity economy in Ukrainian society to maintain fragile stability. The paper investigates the main reasons for the displacement of Ukrainians, explores the living conditions in communities where they moved, and identifies the main socioeconomic factors for ensuring the resistance of the individual and the community in wartime. The paper applies the sociological survey involving 1,200 respondents. The results show that Ukrainians recognize the authority’s right to make authoritarian decisions. The analysis gives empirical evidence on the sources of social and economic resistance and sustainability in Ukraine. This includes quantifying the role of social and financial payments, examining the intensification of social and solidarity ties, and evaluating the importance of a social solidarity economy for resilience. The study revealed the directions of supporting stability within the social solidarity economy in Ukraine under war conditions. They include incentive programs for returning qualified personnel, powerful tools of social support, encouraging socially-oriented small businesses, remote employment, state and local programs to support public organizations, and financing local initiatives.

Acknowledgments
The publication was prepared within the project Jean Monnet Module “Social Solidarity Economy: implementing EU experience for Sustainable Development” (SSExpEU-101047518-GAP-101047518) (2022–2025), funded by the European Union.

The current green agenda, the climate change, and sustainability frameworks are closely linked to the successful transition to renewable energy. The study purpose is to estimate the influence of economic and environmental drivers of renewable energy promotion in the EU-27, using the 2013–2021 data for member states. Breusch and Pagan Lagrangian multiplier test and Hausman specification test were performed to determine the proper model specification. Using random-effects GLS regression for selected data, the study found that the rise in the magnitude of the Land-Ocean Temperature Index by one unit contributes to an increase in renewable energy sources by 10-16 percentage points. The rise in natural gas prices in the EU by USD 10 per MMBtu is associated with an average growth of renewable energy sources by 2.1-2.6 percentage points and three percentage points for growth in renewable electricity. An increase in GDP per capita of USD 1,000 led to an average increase in renewable electricity by 0.2 percentage points. An increase in CO2 per capita by one ton is associated with an average decrease in renewable electricity by 0.85 percentage points. This study proves that the critical point of GDP per capita within the “economic growth/renewable energy” nexus when economic stimulus starts to decline was estimated at USD 121,227-148,623. Thus, for countries that have reached the break-even point in GDP per capita, the incentives for introducing renewable energy sources are reduced when the effect of wealth prevails over the impact of environmental awareness and responsibility.

Acknowledgments
This paper is supported by a grant “Formation of Economic Mechanisms to Increase Energy Efficiency and Provide Sustainable Development of Renewable Energy in Ukraine’s Households” (No. 0122U001233), funded by the National Research Foundation of Ukraine.

Type of the article: Research Article

Abstract
The paper aims to develop and adapt an econometric model for assessing and forecasting the impact of household energy efficiency and renewable energy deployment on reducing energy poverty in Ukraine. Due to the lack of updated statistical data after 2022 caused by the war, the adapted model was tested using pre-war data from the State Statistics Service of Ukraine and the World Bank for 2002–2021. As access to some pre-war datasets was also restricted for security reasons in Ukraine, proxy indicators were applied, allowing adaptation to limited information conditions. The modeling results showed that a 1,000 USD increase in GDP per capita reduces the share of the population living below the national poverty line and, accordingly, the energy-poor population, by 3%. Conversely, a 1% increase in gross capital formation raises the energy poverty level by 0.5%, indicating no direct impact of investment in physical capital, including expenses on energy-efficiency measures, on household welfare. Household expenditures on utilities and the share of renewable energy in total energy consumption were found to be statistically insignificant. The study confirms that household income remains the dominant determinant of energy poverty, while improvements in energy efficiency and renewable energy development play supportive but not yet decisive roles. These findings highlight the need to integrate social and energy policies to raise household incomes, improve access to renewable technologies, and promote energy efficiency measures. The developed model offers a tool for enhancing state policies to alleviate energy poverty under wartime constraints and in post-war recovery.

Acknowledgments
This study was funded by the National Research Foundation of Ukraine within the project “Formation of economic mechanisms to increase energy efficiency and provide sustainable development of renewable energy in Ukraine’s households” (No. 0122U001233).

This paper elaborates on the theoretical and methodological fundamentals of a tradable green certificates system to foster renewable energy development in Ukraine. It proposes a management mechanism premised on the classical market model of tradable green certificates aiming at increasing the share of electricity from renewable energy sources in the country’s energy mix. Organizational stages of the mechanism formation at the national level and a methodological approach to assess green electricity generation cost are developed. The modeling has shown that the annual increase in the cap for green electricity consumption by 1% will raise the electricity tariff by 3%, which is not a significant financial burden for consumers. The proposed changes in the tradable green certificates system can be an effective management tool to achieve the required amount of electricity from renewable energy sources in the country’s total electricity consumption and to foster the development of the Ukrainian renewable energy sector.

Type of the article: Research Article

Abstract
The study examines regional convergence and divergence in the development of household solar energy in Ukraine during 2016–2022 and explores implications for adaptive energy management and policy coordination. Using β- and σ-convergence models, the analysis investigates whether regional household solar electricity generation demonstrates tendencies toward structural alignment or, conversely, follows autonomous trajectories that indicate the absence of a common attractor. The results reveal a lack of both beta- and sigma-convergence, implying that initial regional conditions exerted little influence on subsequent development and that disparities across regions have persisted or even deepened over time. These findings suggest a divergent and spatially fragmented pattern of solar energy expansion, where regional dynamics are determined not only by differences in economic and institutional capacity but also by disruptions linked to the onset of the full-scale Russian invasion in 2022. The study emphasizes the need for a more adaptive and integrated energy policy that recognizes regional heterogeneity, supports decentralized renewable energy deployment, and strengthens coordination between national and local authorities. Such an approach would enhance the effectiveness of planning and implementation of household renewable energy programs, contributing to a more balanced and resilient low-carbon transition in Ukraine.

Acknowledgments
The publication was prepared in the framework of the research project “Formation of economic mechanisms to increase energy efficiency and provide sustainable development of renewable energy in Ukraine’s households” (No. 0122U001233), funded by the National Research Foundation of Ukraine.

Type of the article: Research Article

Abstract
This study aims to assess a macroeconomic methodological approach for evaluating the impact of investment activity, energy efficiency, energy costs, and renewable energy development on CO₂ emissions in Ukraine, using the model’s insights for a conceptual extrapolation to the residential sector with subsequent policy scaling to the municipal building stock. The methodological basis is a top-down approach using econometric modeling (OLS) for 2002–2021, which represents the pre-war period in Ukraine. All estimations are based on aggregated macroeconomic proxy indicators and not on direct residential or municipal emissions measurement data due to a lack of reliable information. The results demonstrate that macroeconomic energy efficiency is the most powerful driver of decarbonization. An analysis of the residential sector indicates that higher household financial burdens associated with higher utility expenditures are statistically connected with lower CO₂ emissions, which may reflect demand-side adjustments in energy consumption, including price-driven savings. However, other factors, such as energy inefficiency or energy poverty, may also add to this relationship. In contrast, traditional investment activity still contributes to growing carbon footprints, with CO₂ emissions rising by 136 kg per 1% increase in gross capital formation as a share of GDP. At the same time, the estimated coefficients for global oil prices and the share of renewable energy exhibit the expected negative signs, suggesting economically meaningful long-term decarbonization tendencies. However, these relationships do not reach conventional statistical significance and should therefore be interpreted as directional trends rather than statistically confirmed effects.

Acknowledgments
This paper is funded by the Ministry of Education and Science of Ukraine within the projects “Comprehensive vertically integrated intelligent system for monitoring and regulating energy supply in municipal sector buildings” (No. 0126U000867) and “Drivers and barriers to human capital transformation for a circular and green economy” (No. 0126U001080).