Renewable Energy for Sustainable Development in EU Countries: Status, Prospects, and Challenges

Abstract

This study aims to present the current status and forecasts related to the generation of energy from renewable sources, as well as the challenges and barriers resulting from the development of this energy in the European Union countries. The research procedure consists of three stages: bibliometric analysis of scientific publications conducted based on the Web of Science database, visualization of results using VOSViewer software (version 1.6.20), and in-depth analysis of the content of the publications. The study covered two periods. The first one covered the years 1990–2024, in which publications on sustainable development and renewable energy sources began to appear around the world. The second one included publications from 2002, because the first works on European Union countries were identified in that year. The final sample included 96 articles that identified key links between sustainable development and renewable energy. These topics accounted for 50% of all issues discussed in these articles. It turned out that one of the most important challenges of modern economies (21.9% of the articles examined) is finding a balance between sustainable economic growth and limiting environmental degradation. The literature review also shows that the renewable energy sector in the EU and its Member States is developing dynamically. This was confirmed by Eurostat data on both renewable energy production and consumption.

1. Introduction

Energy obtained from renewable sources (sun, wind, water, earth, biomass) is often called “clean” or “green” energy, because its production and consumption do not negatively affect the natural environment. Therefore, it is a significant alternative to energy produced from fossil energy sources (coal, natural gas, oil) and its development is a guarantee of increasingly better environmental quality in the future.

Taking care of the natural environment is part of the idea of sustainable development, according to which such development should “ensure that the needs of the present are met without compromising the ability of future generations to meet their own needs” [1]. This definition does not directly refer to environmental protection, but the explanation regarding the ability of future generations to meet their own needs clearly indicates that this refers to the ability of the environment. The connection between environmental protection and sustainable development was clearly emphasized at the United Nations Conference on Environment and Development (UNCED), which took place in Rio de Janeiro on 3–14 June 1992. In the Rio Declaration on Environment and Development, Principle 4 states that “in order to achieve sustainable development, environmental protection shall constitute an integral part of the development process and cannot be considered in isolation from it” [2].

The issues related to both sustainable development and the use of renewable energy were and are so important that they have been reflected in many publications around the world. The Web of Science database was the first to publish (since 1990) studies on sustainable development, and a year later publications related to renewable energy began to appear. In the years 1991–2024, in addition to works that treated the issues of sustainable development and renewable energy separately, studies appeared that considered these two issues together.

The multitude of publications on these issues prompted the authors of this study to conduct an in-depth analysis of their content—with particular emphasis on publications from European Union (EU) countries—in order to indicate the most important research problems in this area. The main emphasis was placed on the issues related to the generation of energy from renewable sources in the context of sustainable development in EU countries.

Referring to the general objective given above, two specific objectives were formulated as follows:

• To present the current status and development prospects for generation of energy from renewable sources in the EU countries;
• To identify barriers related to the production and consumption of energy from renewable sources in the EU countries and recommend solutions that can improve the energy transformation process.

In order to achieve the assumed general objective and specific objectives as reliably as possible, four research questions were formulated:

• How did the renewable energy sector develop in the EU and in the Member States?
• What are the main advantages of renewable energy and how does it affect sustainable development?
• What are the main barriers related to the process of implementing renewable energy and what should be done to improve this process?
• What topics related to renewable energy are most often discussed in the literature, and which appear the least often?

In order to answer the above questions, a research procedure consisting of three stages was used: bibliometric analysis of scientific publications conducted based on the Web of Science database, visualization of results using VOSViewer software, and in-depth analysis of the publication content. The study covered two periods. The first one covered the years 1990–2024, in which publications on sustainable development and renewable energy sources began to appear around the world. The second one included publications from 2002, because this was the year that works on European Union countries were identified.

This article complements the world literature by providing a comprehensive analysis of renewable energy in the context of sustainable development. It shows the barriers that limit the development of renewable energy in many countries, at the same time providing recommendations that can significantly improve the energy transformation process. Moreover, thanks to the applied research method, it highlights research gaps, among which, according to the authors, the first place is taken by the lack of publications on environmental education, which can significantly affect the acceptance of energy transformation by society. Both the comprehensive analysis of the studied phenomenon and the identification of barriers, recommendations and research gaps distinguish this article from others and constitute its added value.

The article consists of six sections. Section 1 is an introduction, which explains the authors’ most important motivations for conducting research on the use of renewable energy in the context of sustainable development, presents the research goals and questions, and indicates the method used in the study. Section 2 presents the description of the research procedure, while Section 3 presents the results of the bibliometric analysis. Section 4, based on a literature review, presents the status and development prospects for energy obtained from renewable sources, indicated barriers and solutions that can improve energy transformation were recommended. In Section 5—in the form of a discussion—the importance of the topic was emphasized, the advantages of renewable energy were highlighted, but also the weaknesses of these solutions were indicated, which translate into, among others, that the speed of energy transformation in EU countries is diversified and a clear division in this respect into “old” and “new” EU countries is visible. The last section presents final conclusions and directions for future research.

2. Research Methodology

In order to demonstrate the interdependencies between sustainable development and energy generation from renewable sources, a three-stage research procedure was carried out.

The first one includes bibliometric analysis. It is a method of exploration and quantitative analysis of the authors’ publications and may concern the publications of one or a group of authors. The analysis is carried out based on selected databases. In a broader context, bibliometric analysis also includes analysis of the relationships between the elements covered by the study. The analysis uses various databases and bibliometric indicators (e.g., number of publications, number of citations, Hirsch index). This paper reviews the literature based on the search results from the Web of Science database [3]. The study was conducted in two stages. The first one (preliminary stage) covered the period 1990–2024, in which publications on sustainable development and renewable energy sources began to appear in the world. The second one (proper stage) covered publications from 2002, because in that year works were identified that allowed for the presentation of the current state and forecasts related to the generation of electricity from renewable sources, as well as challenges and barriers resulting from the development of this energy in the European Union countries, which is in line with the aim of the study.

In the Web of Science Core Collection (WoS-CC) database [3], 44,794 publications (articles, proceeding papers, books, and book chapters) were indexed, in which the phrase “sustainable development” appeared among the keywords, and 49,143 publications with the phrase “renewable energy sources”. They were published in the years 1990–2024. Both of the above phrases appeared simultaneously in 1168 publications. Among these publications, only in 96 cases, records [4] of the WoS-CC database contained the phrase “EU”. Figure 1 presents a flow diagram for systematic reviews according to the PRISMA methodology [5].

In the second stage, VOSViewer software (version 1.6.20) [6] was used to visualize the results of the bibliometric analysis and create a keyword occurrence network. VOSViewer is a free software that is able to analyze a large amount of data and provide excellent mapping of network data. In addition, it offers the possibility of building a co-occurrence network of important terms extracted from the scientific literature using the text mining functionality [7,8]. The use of this method allowed us to indicate the frequency of terms and key research areas related to sustainable development and renewable energy in EU countries.

The last stage is an in-depth analysis of the content of publications, allowing for the identification of the most important research problems related to renewable energy production in the context of sustainable development in EU countries. It allowed for the presentation of both the state of research, development prospects, as well as key barriers and challenges in this area.

3. Results of Bibliometric Analysis

In the years 1991–2024, 1168 publications indexed in WoS appeared worldwide, which included in the same time phrases “sustainable development” and “renewable energy” among the keywords (see Figure 1). The evolution of the number of publications and citations of these works in this period is presented in Figure 2. As can be seen at the beginning of the period under review, eight publications appeared, and their number systematically increased year by year, reaching 198 publications in 2024. The number of citations of these works also increased, especially since 2018. In 2023, their number amounted to almost 4000, after which a decrease was noted to 827 in 2024.

The analysis of the authors’ country of origin (Figure 3) shows that the relationship between renewable energy and sustainable development was studied by researchers from all over the world, with the majority coming from Asia (44%) and Europe (35.8%).

Then, for these publications, the number of articles in each country was analyzed and the first “global” five were included China (196 authors), Poland (106 authors), India (91 authors), Great Britain (90) and the USA (85 authors). Among the other countries belonging to the European Union, it is also worth mentioning Italy (65 authors), Germany (41 authors), Spain (38 authors), and Romania (37 authors).

Of the 1168 publications discussed, only 96 concerned EU countries. As can be seen in Figure 4, the first article in this field was published in 2002. Their number began to increase from 2018, with the highest number appearing in 2023. The published works were cited almost 2000 times, with the highest number of citations appearing in 2019 (448 citations), after which their number dropped to 45 in 2024.

The issue of the relationship between renewable energy and sustainable development, with particular emphasis on EU countries, was dealt with primarily by researchers from Europe, most of whom came from Poland (35 authors), Ukraine (11 authors) and Greece (10 authors) (Figure 5). It is worth noting, however, that the analyzed issue was also of interest to authors from other continents, including Asia (eight authors), North America (four authors) and Africa (four authors).

Articles in this field have been published in journals such as: Energies, Biomass & Bioenergy, Journal of Cleaner Production, Sustainability, Expert Systems with Applications, Renewable Energy, Sustainable Development, Energy, Environmental Research, Journal of Ecological Engineering, Economics and Environment, and Renewable & Sustainable Energy Reviews. Figure 6 presents information on the five journals with the highest total number of citations.

The highest total number of citations of works on the relationship between renewable energy and sustainable development in EU countries was recorded for the Energies journal—747 out of 28 articles. In the case of Biomass & Bioenergy, Journal of Cleaner Production, and Expert Systems with Applications, the values presented in Figure 6 were achieved by individual publications. In turn, the number of citations for the Sustainability journal was achieved by six articles. Despite the large disproportion between the values obtained for journals from the MDPI publishing house (Energies, Sustainability), their average number of citations per article was similar and amounted to 26.7 and 22.2, respectively.

Table 1. Ten publications with the highest number of citations in the Web of Science Core Collection database.

Author	Title	Journal	Year	Citations
McCormick, K; Kåberger, T	Key barriers for bioenergy in Europe: Economic conditions, know-how and institutional capacity, and supply chain coordination [9]	Biomass & Bioenergy	2007	159
Bórawski, P; Beldycka-Bórawska, A; Szymanska, EJ; Jankowski, KJ; Dubis, B; Dunn, JW	Development of renewable energy sources market and biofuels in The European Union [10]	Journal Of Cleaner Production	2019	156
Lyeonov, S; Pimonenko, T; Bilan, Y; Streimikiene, D; Mentel, G	Assessment of Green Investments’ Impact on Sustainable Development: Linking Gross Domestic Product Per Capita, Greenhouse Gas Emissions and Renewable Energy [11]	Energies	2019	137
Vasylieva, T; Lyulyov, O; Bilan, Y; Streimikiene, D	Sustainable Economic Development and Greenhouse Gas Emissions: The Dynamic Impact of Renewable Energy Consumption, GDP, and Corruption [12]	Energies	2019	134
Doukas, H; Karakosta, C; Psarras, J	Computing with words to assess the sustainability of renewable energy options [13]	Expert Systems With Applications	2010	124
Swain, RB; Karimu, A	Renewable electricity and sustainable development goals in the EU [14]	World Development	2020	108
Cirstea, SD; Moldovan-Teselios, C; Cîrstea, A; Turcu, AC; Darab, CP	Evaluating Renewable Energy Sustainability by Composite Index [15]	Sustainability	2018	59
Guzovic, Z; Duic, N; Piacentino, A; Markovska, N; Mathiesen, BV; Lund, H	Recent advances in methods, policies and technologies at sustainable energy systems development [16]	Energy	2022	59
Fotis, P; Polemis, M	Sustainable development, environmental policy and renewable energy use: A dynamic panel data approach [17]	Sustainable Development	2018	53
Wuebben, D; Romero-Luis, J; Gertrudix, M	Citizen Science and Citizen Energy Communities: A Systematic Review and Potential Alliances for SDGs [18]	Sustainability	2020	52

Source: own study based on WoS-CC.

presents information on the most frequently cited publications concerning the studied phenomenon.

The following issues were discussed in the articles presented in Table 1:

• Identification of barriers to bioenergy in the EU [9];
• Development of the renewable energy market with a special focus on biofuels in the EU [10];
• Assessment of the impact of green investments on sustainable development, linking gross domestic product per capita, greenhouse gas emissions, and renewable energy [11,12];
• Relationships between sustainable development and renewable energy sources [13,14,15,16];
• Relationship between environmental sustainability policy and the use of renewable energy [17];
• Citizen science and citizen energy communities [18].

The identified 96 publications were subjected to a detailed examination using VOSviewer software version 1.6.20. Analysis of these publications, taking into account the co-occurrence of at least four keywords, allowed for the identification of five clusters (Figure 7):

• CO₂ emissions, consumption, economic growth, electricity, energy consumption, energy transition, power, renewable energy sources, sustainable development goals, transition (red links);
• Biomass, design, efficiency, emissions, energy policy, EU, generation, model, sustainability (green links);
• Climate change, energy, innovation, management, performance, renewable energy, sustainable development (blue links);
• Market, technology, wind energy (yellow links);
• Green economy, impact (purple links).

The selected keywords (energy sources and sustainable development) appear only in the first and third cluster and are related to, among others, economic growth and energy transformation (cluster 1) and climate changes and innovation in renewable energy production (cluster 3). The second cluster refers to, among others, issues related to energy policy, energy generation, climate change, and sustainable development. The fourth cluster primarily concerns technology, market, and wind energy. In the fifth cluster, there are keywords such as green economy and impact.

Despite the fact that the two key words did not appear simultaneously in the second, fourth, and fifth clusters, there are words that are inextricably linked to both renewable energy and sustainable development. In the second cluster, the word energy appears together with climate change and sustainable development. In the fourth cluster, wind power refers to renewable energy, while in the fifth cluster there is the concept of green economy, which in its broad sense can include sustainable development and renewable energy.

Detailed analysis shows that in individual clusters, in terms of the number of occurrences and total link strength values, the following keywords dominate:

• In cluster one: renewable energy sources (31 occurrences, total link strength: 90);
• In cluster two: EU (11 occurrences, total link strength: 39);
• In cluster three: sustainable development (88 occurrences, total link strength: 239) and renewable energy (60 occurrences, total link strength: 177);
• In cluster four: all three keywords occurred four times, but they differed in the value of the total link strength parameter: market (21), technology (17), wind energy (18);
• in cluster five: impact (8 occurrences, total link strength: 39).

An in-depth analysis of the selected 96 works, taking into account the co-occurrence of at least ten phrases in the abstracts, allowed for the identification of two clusters (Figure 8):

• Climate change, context, data, emission, greenhouse gas emission, increase, order paper, Poland, reduction, renewable energy source, share, use (red links);
• Challenge, economic growth, impact, process, research, solution, study, sustainability, sustainable development goal, time (green links).

The first cluster refers directly to renewable energy sources and their level, share, and impact on the level of greenhouse gas emissions. The case of Poland has been analyzed particularly often in this context. The second cluster refers directly to issues related to sustainable development and the impact on the economy and economic growth.

A detailed analysis of the links between the map elements presented in Figure 8 shows the following:

• In the first cluster, the highest number of occurrences was characteristic of the following keywords: data (27 occurrences); paper (31 occurrences) and renewable energy source (27 occurrences). This also resulted in their highest total link strength, which was 133, 130, and 124, respectively;
• In the second cluster, the dominant keywords in terms of the number of occurrences were as follows: study (43 occurrences), impact (34 occurrences), research (31 occurrences), challenge (24 occurrences). In their case, the total link strength was 191, 151, 148, and 116, respectively.

The analysis of 96 papers selected for the study also allowed for the identification of relationships between variables from the category of sustainable development and renewable energy sources (Figure 9). The most frequently discussed topics in the articles were related to the assessment of the level of development of renewable energy sources in the member states (28.1%) and the relationship between the use of renewable energy sources and sustainable development (21.9%). In third place, with a slightly smaller share (15.6%), were papers showing the relationships between energy policy and sustainable development. Energy policy plays a key role in promoting sustainable development by directing the transition from fossil fuels to renewable energy sources. Unfortunately, a number of regulatory policies, and technical and economic barriers hinder the widespread use of renewable energy sources (8.3% of papers). It is also worth paying attention to papers on the impact of renewable energy on the quality of the natural environment, energy transformation, and the impact of “green investments” on “green” economic growth. The share of each of them exceeded 5% of all the works examined.

Based on the above bibliometric analysis, certain research gaps can be noticed, as the distinguished clusters did not include words such as ecological education, social acceptance, energy poverty, and specific types of renewable energy sources (except wind energy).

4. In-Depth Content Analysis

4.1. Current Status of Renewable Energy and Prospects for Its Development

The key moment of intensification of research and development works in the field of renewable energy sources and energy systems was the oil crisis in the early 1970s [19]. These studies showed a number of benefits that energy transformation can bring. The most important factors driving energy transformation turned out to be mitigating climate change, strengthening energy security, ensuring economic competitiveness, ensuring social justice, reducing energy poverty, and stimulating technological innovations [20]. Hence, the conclusion that the pursuit of obtaining energy with minimal costs and environmental pollution is still developing and will continue in the future [21]. It is worth noting that a revolution in the energy sector is already underway all over the world, which aims to switch to the greatest possible extent to energy from renewable sources.

The literature review shows that energy transformation has become a necessity in countries with different levels of development, as renewable energy sources are the only alternative to traditional sources. A review of the development prospects for renewable energy on an international scale was conducted by, among others, L. Li et al. [22]. In their research, they analyzed the energy transformation in the European Union, India, Australia, Brazil, and the United States. The analysis shows that in the EU, the consumption of energy from renewable sources is systematically growing, the renewable energy industry is developing faster and faster, and greenhouse gas emissions are decreasing. This trend is also noticeable in the other economies studied, where the expansion of renewable energy over the past few decades and the rapid development of renewable energy technologies for energy production show that the transformation of the energy structure can achieve ambitious goals in the field of climate change mitigation.

The acceleration of the energy transition has created new phenomena that economies have to cope with, including: the complex interaction of multiple technologies, the collapse of established business models and technologies, the intensification of economic and political struggles between key actors such as utilities and industry associations, and serious challenges to the overall functioning and efficiency of the electricity sector (for example, when integrating renewable energy sources) [23]. Financial markets that support green initiatives also have a significant impact on the energy transition [24].

For the European Union, sustainable development and green policy are of key importance [25]. Of the proposed definitions of sustainable development, the most common seems to be the one that assumes that it is development that meets the needs of the present without compromising the ability of future generations to meet their own needs [1]. According to Kumar and Majid [26], sustainable development is possible thanks to the use of sustainable energy and providing citizens with access to affordable, reliable, sustainable, and modern energy. This thesis is confirmed by S. Sen and S. Ganguly et al. [27,28], who claim that sustainable socio-economic development requires secure energy supplies at affordable prices, with a low impact on the environment and low greenhouse gas emissions. After reviewing the research on renewable energy in the context of sustainable development, Dincer [19] concluded that the use of renewable energy sources is an essential element of sustainable development for three important reasons: they have a smaller impact on the environment compared to other energy sources, they cannot be exhausted (compared to fossil fuels), and they support the decentralization of the electricity system. Therefore, in order to achieve sustainable development without harming the climate, a significant change in energy forms is necessary [21,29,30,31,32]. The results of many analyses [33,34,35,36] confirm that the role of renewable energy in the sustainable development of the electricity sector is important, mainly due to environmental protection, improving the sources used for electricity generation and creating new business opportunities for companies and individuals.

An interesting review of works on renewable energy was made by Osman et al. [37], addressing such issues as: costs, climate impacts on renewable energy, impacts of renewable energy on the environment, economy, and decarbonization in different countries of the world, including European countries. The authors focused on solar, wind, biomass, hydro and geothermal energy. This review also examined the impacts of different renewable energy sources on the environment.

The European Commission documents assume that in 2050 over 80% of electricity will come from renewable energy sources [38]. At the beginning of 2021, countries that are responsible for over 65% of global CO₂ emissions, together with 70% of the world’s economies, made commitments to become carbon neutral countries. In line with these commitments, the European Union, Japan, South Korea, and over 110 other countries declared that they would become zero-emission economies by 2050. China and the United States have also shown such intention, with China declaring that their country will have a zero-emission economy by 2060 [39]. Such a distant deadline for the implementation of this commitment is a consequence of the fact that the transformation of the energy economy to zero-emission is a difficult undertaking, both from a social and technical point of view. Therefore, the transition to a climate-neutral economy by 2050 seems to be a particularly big challenge for developing European countries. This is primarily due to their economic conditions, as these economies were primarily based on traditional energy sources. Although in these countries the use of fossil fuels is still dominant in energy production, as the change of technology is time-consuming, it is assumed that new (renewable) energy sources must be implemented on a scale comparable to the industrial revolution [40].

The current state of renewable energy in the European Union and the analysis of changes in this sector in the years 2008–2018 were assessed by J. Brodny et al. [41]. In their research, they used a set of 11 indicators characterizing renewable energy in individual countries. Principal component analysis (PCA) was used to assess the state of renewable energy, and the TOPSIS method was used to analyze the pace of its development in EU countries. Based on the conducted research, it was found that the European energy transformation is progressing at a rapid pace, and the undisputed leaders in terms of renewable energy production are Sweden, Austria, Finland, and Latvia.

Also A. Shivakumar et al. [42] conducted an analysis of the current state (which enabled identification of factors and barriers enabling the implementation of RES in the past) and a review of forecasts regarding the use of RES in the EU. According to the authors, a comparison of different studies and scenarios can help to better understand the factors influencing the forecasts of future implementation of RES. As it results from their research, the impact of a given factor on the investment climate is different in each Member State. A specific barrier or factor of RES development in one country may be of key importance, while being insignificant in another country. On the other hand, a key factor enabling the successful implementation of RES technologies is policy certainty.

D. Čeryová et al. [43] also studied renewable energy in the EU. The main objective of their study was to assess the European Union countries in terms of achieving above-average, average, and below-average values of selected renewable energy indicators in the years 2009–2016. The analysis shows that most countries do not have a clearly defined goal and in most cases they are in the range of average and below-average values in the period under review. An example of a country with a clearly defined policy aimed at the development of renewable energy sources was Finland, which maintained above-average values of electricity production throughout the monitored period, especially in the hydropower and biomass sectors.

The analysis of sustainable development of renewable energy in selected 18 European countries in the years 2007–2016 was conducted by Q. Wang and L. Zhan [44]. It turned out that the consumption of renewable energy in these countries constitutes about 95% of the consumption of renewable energy in the EU. Moreover, the conducted studies show that the sustainable development of renewable energy in Germany, Great Britain, France and Italy is faster than in other countries. On the other hand, S. Akadiri et al. [45], based on panel data from 28 European Union countries in the years 1995–2015, assume that achieving the sustainable development goals by 2030 through the use of renewable energy and reducing carbon dioxide emissions is to a large extent achievable in the EU countries and should be adopted by all countries as an effective global policy.

D. Armeanu et al. [46] conducted research in the countries of Central and Eastern Europe in order to identify the cause-and-effect relationship between energy consumption, environmental pollution and economic growth. Their research shows that investments in the development of the renewable energy sector are necessary in this area of Europe, because the infrastructure there is old and outdated. Thus, energy policies aimed at increasing the production and use of renewable energy will reduce the current energy dependence of the countries of Central and Eastern Europe on countries supplying fossil fuels (gas, oil, coal).

The previous considerations concerned the state and development prospects of renewable energy in general, i.e., without division into energy carriers. Below is a review of publications in which research concerned basic sources of renewable energy such as solar, wind, water, geothermal and biomass. The first observation resulting from the research of Singh et al. [47] is that the dominant source of energy in renewable energy is water energy, constituting about 70% of the total renewable energy.

In turn, J. Brodny et al. [48] adopted eight diagnostic variables to analyze the situation in the field of renewable energy in EU countries, which characterized the values of energy produced in a given country using selected renewable energy carriers (water, geothermal, wind, sun, primary solid biofuels, biogases, renewable municipal waste, liquid biofuels). The study was conducted on the basis of data from 2017 using the k-means method in four variants. It was shown that wind energy played the greatest role in adding EU countries to individual clusters, followed by energy produced from biogases. Geothermal energy was the least important factor influencing the addition of EU countries based on the adopted criterion.

P. Bórawski et al. [10] also dealt with the development of the clean energy market with particular emphasis on biofuels in the EU. In their research, they used descriptive and statistical methods to characterize changes in the development of bioenergy in the European Union based on data from 2004 to 2016. It turned out that the largest share of biofuels and renewable waste was recorded in Latvia (31.2%), Finland (26.7%), and Sweden (24.8%).

The state of renewable energy in developing European countries was studied by T. Pakulska [49], focusing on the countries of Central and Eastern Europe (CEE) and classifying them based on taxonomic methods from the point of view of green energy transformation. According to T. Pakulska’s research and data from the International Renewable Energy Agency (IRENA) [50], the greatest potential of electricity obtained from RES is characteristic of Romania, Poland, and Bulgaria. Among the countries of Central and Eastern Europe, there is a certain specialization in the structure of electricity generated from RES. In Latvia, Slovenia, Slovakia, Romania, and Bulgaria, hydropower is of great importance. In the case of wind energy, Lithuania and Poland are leaders. On the other hand, Hungary and the Czech Republic stand out in terms of power generated from solar energy.

According to Eurostat data [51], in 2005, the share of electricity obtained from renewable energy sources in total electricity production in the EU was 2.5%, and in 2023 it was already at the level of 25.8%. Electricity production from renewable sources in 2005 was 3847.5 GWh, and in 2023 it was 45,853.4 GWh. The share of final energy consumption from renewable sources in total energy consumption in the EU was 6.7% in 2005, and in 2023 it was 12.5%. The increase in electricity generated from renewable energy sources between 2013 and 2023 largely reflects the expansion of two renewable energy sources across the EU, namely wind and solar energy. In 2023, renewable energy sources accounted for 45.3% of gross electricity consumption in the EU, which is more than 4 percentage points more than in the previous year (41.2% in 2022). Wind and hydropower accounted for more than two-thirds of total electricity generated from renewable sources (38.5% and 28.2%, respectively). The remaining third of electricity generated came from solar energy (20.5%), solid biofuels (6.2%) and other renewable sources (6.6%). Eurostat data also shows that the fastest growing renewable energy source was solar energy, which in 2008 accounted for only 1% of energy obtained from renewable energy sources. This means that the increase in electricity production from solar energy increased from 7.4 TWh in 2008 to 252.1 TWh in 2023.

It should be noted that biomass is primarily used as an energy source in heating. Traditional biomass remains the dominant fuel source for cooking and heating in low-income households in rural and urban areas [27,47]. According to research by the International Renewable Energy Agency (IRENA) conducted together with the European Commission [52], it is assumed that after 2030, biomass (together with solar and wind energy) will play an important role in the transition to renewable energy in electricity generation.

Although geothermal energy is not a major energy source in any of the EU countries, Dalla Longa et al. [53] predict that in 2050 energy production using geothermal technology may constitute 4% to 7% of total energy production in Europe.

Table 2. Main sources of renewable energy in selected European countries.

The Main Source of Renewable Energy	Countries
Solar energy	Hungary, Czech Republic, Germany, Spain
Biomass	Albania, Croatia, North Macedonia, Serbia, Montenegro, Greece, Germany, Finland
Geothermal energy	It is not the main source of energy in EU countries.
Wind energy	Lithuania, Poland, Germany, Spain, Ireland, Portugal
Hydro energy	Albania, North Macedonia, Bosnia and Herzegovina, Latvia, Slovenia, Romania, Bulgaria, Slovakia, Finland

Source: own study based on: [41,42,43,49,54,55,56].

lists selected European countries in terms of their main sources of renewable energy.

Table 3. Publications on the current status and forecasts related to the use of renewable energy sources in the EU.

Examination of the Current State	Forecasts
D. Lalic et al. [54], L. Li et al. [22], J. Brodny et al. [24], Brodny et al. [41], E. Soares-Ramos et al. [57], Q. Wang, L. Zhan [44], D. Čeryová et al. [43], A. Shivakumar et al. [42]	T. Pakulska [49] D. Lalic et al. [54], S. Potrč et al. [58], E. Soares-Ramos et al. [57], A. Shivakumar et al. [42], R. Bointner et al. [59]

Source: own study.

presents selected literature items divided into authors examining the current state of renewable energy and authors forecasting its future results.

Table 3 shows that there are slightly more publications presenting research on the current state of renewable energy than its forecast, with most of these publications addressing both issues. Among the publications on forecasts, interesting conclusions come from the research by S. Potrč et al. [58]. According to authors, the forecasts for the use of energy from renewable sources in the EU are as follows: wind turbines will remain a key transformation technology in the first years, the use of photovoltaic panels will increase after 2030, and in 2050 photovoltaics will generate 43% of all electricity from RES. It is also worth noting the difficulties of countries in obtaining energy from renewable sources resulting from their limited surface area, hence the development of offshore wind farms seems to be important. Analyses of the current state and development trends of large-scale offshore wind farms were conducted by E. Soares-Ramos et al. [57]. As it results from these studies, the world leaders in operating high-capacity offshore wind farms are Germany and Great Britain. It is also emphasized that offshore wind energy is the largest renewable energy technology in terms of the possible range of application [60]. This is confirmed by the research conducted by D. Atstāj [61], according to which the countries of the Baltic Sea region are intensifying their efforts to develop renewable energy, in particular wind energy (both onshore and offshore) and solar energy, which may lead to energy self-sufficiency in this part of Europe.

To conclude the considerations in this subchapter, it should be emphasized that countries where the use of energy from renewable sources is at a moderate level, estimate their potential and strive to develop investments related to specific renewable energy carriers, because the source of renewable energy and its potential are influenced by the location of the country/region, i.e., radiation, wind speed, topography, terrain slope, etc. It should be noted that EU countries have very good access to all renewable energy sources. However, there are significant differences in this respect in individual countries. Natural conditions (geographic, geological, ecological) are undoubtedly of great importance. The availability of geothermal waters has a significant impact on the development of geothermal energy, while the size of watercourses and the potential of falling water within the country have a significant impact on the development of hydropower. In the production of energy from biomass, the size of the country’s area and the degree of its forestation play a key role. In turn, wind energy is based on the size of the country’s area (it should be remembered about areas excluded from the possibility of locating RES installations) and wind conditions, and in the case of photovoltaics—the number of sunny days per year and the degree of insolation [41].

When considering renewable energy generation in Europe, as already mentioned, the specificity of individual areas is noticeable. The Baltic Sea has significant potential for both onshore and offshore wind energy, and its competitiveness varies depending on wind conditions, connection costs, and market value. The southern Baltic offers areas of high value for wind energy generation [61]. On the other hand, the Nordic countries are leading in the overall efforts to build a cleaner economy, with Sweden and Denmark being leaders in both 2005 and 2015. Sweden had the best combination of inputs and outputs, leading in the development of renewable energy sources, which benefited from the energy intensity of the economy and greenhouse gas emissions. Denmark contributed to the best environmental taxation and gained from the energy intensity of the economy and energy independence. The Danish renewable energy system is mainly based on wind power and is the leader in terms of installed wind capacity per capita. Sources such as biomass, solar power, hydropower, geothermal energy, and biofuels also contribute significantly to electricity generation [41,62].

It is assumed that the choice of the best energy mix depends mainly on the country’s equipment and geographical conditions for RES, there is no doubt that progress in the field of clean energy is limited mainly by the national energy and environmental policy [62].

4.2. Barriers and Recommendations

According to the latest research, in 2023 the world will see an unprecedented 14% increase in renewable energy generation capacity, making renewable energy the fastest growing source of electricity. However, the record progress is far from tripling the target in this regard, to which countries committed at the UN climate change conference held in 2023 in Dubai COP28 [63]. The inability to achieve this goal and the varied degree of use of energy from renewable sources in the EU countries is a consequence of numerous barriers that can be considered in the following categories: financial and economic, regulatory and institutional, technical, infrastructural and innovative, social, environmental [63,64]. Similar categories of barriers hindering the implementation of RES projects were indicated by S. A. Qadir et al., where they distinguished economic, institutional, technological and social barriers [65]. These barriers were also confirmed in scientific papers presented at the Sustainable Energy and Environmental Protection (SE-EP) conference, which took place at the University of the West of Scotland in Great Britain in 2018. These works show that the lack of appropriate regulatory policies, as well as technical and economic barriers, hinder the widespread use of renewable energy sources.

Identification of these barriers provides the basis for making recommendations that can improve the energy transformation process.

4.2.1. Barriers to Renewable Energy Development

Economic Barriers

Economic barriers are among the most frequently mentioned barriers encountered when implementing work on renewable energy sources [54,66]. Studies conducted by many authors confirm that the development of RES in European countries requires, above all, huge financial outlays [48,67,68]. The initial investment costs related to the launch of energy production from renewable sources are particularly high. Therefore, the capital intensity of the renewable energy sector is higher than in the case of energy from fossil fuels [69]. Therefore, in order to encourage investment in RES and, thus, to reduce energy production from traditional sources, an appropriate financial support system should be created. S. A. Qadir et al. [65] presented the possibilities of supporting the implementation of RES, among others, by involving financial institutions in providing assistance to the society that wants to invest in renewable energy sources, e.g., in the form of preferential loans or creating and facilitating crowdfunding and crowdsourcing platforms. In addition, the authors recommend the need to present various aspects of renewable energy technologies in order to provide an opportunity to choose the best solution with the available resources.

R. Bointner et al. [59,70] in their studies on financing of renewable energy innovations state that investments in renewable energy R&D are likely to increase in the future, largely driven by the climate goals of the European Union, and that renewable energy sources will become increasingly important for the EU Member States and the European Commission, generating expected investments in renewable energy R&D of EUR 12–21 billion in 2030. The authors developed predictive scenarios of public investment in renewable energy R&D in Europe based on a data set and current trends. These scenarios show the current shift in priorities in favor of public support for renewable energy technologies. The authors suggest that they could be used for further research on the knowledge base of renewable energy sources. The importance of R&D for the implementation of renewable energy sources is confirmed by S. Bose et al. [71]. The authors note that governments must not only more aggressively fund research and early development of renewable energy sources directly but also be more innovative in designing policies and regulations that encourage investment and, thus, more actively cooperate with the private sector in developing new financing solutions. They emphasize that it is necessary to strengthen financing by business angels, VC funds, and public markets. These theses are confirmed by W. Eichhammer et al. [72], who conclude that the task at the political level is to establish an effective framework based on a combination of private and public funds that reduce the risk for companies, are adapted to technological needs and trigger synergistic policies aimed at removing non-economic barriers. Also L. Elie et al. [73], based on a bibliometric analysis of various methods of financing renewable energy sources in the years 1992–2018, noted that most studies focus on market policy instruments used to support RES, and private investments are a new topic that creates a number of opportunities for the development of the RES market and constitutes a significant research gap.

Technological Barriers (Technical, Infrastructural, and Innovation)

According to numerous studies [63,66,74,75,76,77,78], in order to implement and develop RES, it is necessary to improve and modernize the existing network infrastructure, by accelerating the expansion of the network, storage capacity, digitalization and intelligent solutions. On the other hand, innovations in the field of renewable energy are widely considered to be the key to maintaining and improving the quality of life of current and future generations.

Problems with infrastructure have also been noticed by the International Renewable Energy Agency (IRENA). According to the Agency, the condition for the efficient implementation of renewable energy in many countries is the need to accelerate investments in system infrastructure (e.g., power grids, storage) [79].

N. Bamati and A. Raoofi [80], examining the level of advancement and the impact of the technological factor on the production of energy from renewable sources, found that the popularization of RES depends on technical and infrastructural factors to the same extent as on economic, social, or institutional factors. They believe that the export of advanced technologies is of significant importance in solving technical problems.

It should be noted that since the emergence of the carbon footprint concept, there has been ecological pressure on countries that have high carbon dioxide emissions, which is the effect of using energy from non-renewable sources. Therefore, environmental support has a large impact on the factors driving technological support and, thus, on the development of RES projects. This is confirmed by M. Aguirre and G. Ibikunle [81] who examine the determinants of renewable energy growth and conclude that environmental protection drives investments in renewable energy sources.

Institutional (Regulatory) Barriers

The renewable energy sector faces serious obstacles, which very often result from legal regulations in a given country or its specific market conditions. The lack of comprehensive policies and regulatory frameworks limits the adoption of renewable technologies. The renewable energy market requires clear and transparent policies, as well as legal procedures, in order to attract investors. Due to the lack of clear policies in this area, private investments in the renewable energy sector are delayed and suspended in many countries [82]. These observations are confirmed in the research of Y. Liu and C. Feng [83], who claim that energy regulations play an important role in promoting renewable energy.

According to M. Simionescu et al. [56,84], the application of appropriate policies promoting renewable energy sources has a positive impact on their development. They cite countries such as Sweden, Finland, Latvia, Romania, and Portugal as examples, where a subsidy system, quota system, and specific tax regulation mechanisms are intensively used in relation to biofuels and other renewable energy sources.

D. Lalic et al. [54], based on the analysis of the renewable energy market for the Balkan countries, found that in these countries, one of the significant barriers hindering the development of energy from renewable sources is the lack of appropriate legal regulations concerning RES, which in their opinion is a consequence of the fact that renewable energy is not treated as an energy resource that can have a serious impact on the national, regional or local energy balance.

The International Renewable Energy Agency (IRENA) also believes that an important factor that may significantly affect the development of RES is the update of policies and regulations in this area (e.g., energy market regulation, streamlining the permitting process) [66]. Appropriate energy policy was included among the key conditions for the development of renewable energy sources in the EU by M. Papież et al. [85], who analyzed the development of renewable energy sources over a 20-year period, from 1995 to 2014.

N. Bamati and A. Raoofi [80] state that supporting the dissemination of RES depends not only on energy policy and regulations but also on a wide range of economic policies and strategies.

Social Barriers

Studies by many authors (e.g., [48,67,68]) confirm that the development of RES in European countries requires—in addition to huge financial outlays and organizational and economic changes—social acceptance for the energy transformation.

Existing studies lack comprehensive assessments of the acceptance of entire local energy systems, not just their components. This gap is filled by W. Azarova et al. [86], who study local energy communities using renewable energy in order to increase social acceptance. The aim of the study, with the participation of 2000 respondents conducted in four countries (Austria, Germany, Italy, and Switzerland), was to determine which configuration of an energy community based on renewable energy can increase its acceptance by the local community. On the other hand, the results of the research by J. Curtin et al. [87] suggest that building social support for the transition to low-emission technologies can be helped by mobilizing a greater level of private financing through local civic investments in low-emission technologies, which at the same time reduces the shortage of capital to achieve climate goals. It is important that government institutions, decision makers, energy suppliers, and power system operators find a way to jointly offer and promote these services. In their opinion, successful diffusion is conditioned by a significant change in consumer attitudes and behaviors towards renewable energy sources. This results from the fact that consumers must be convinced that they have an impact on the efficiency and sustainability of the power system (education and advertising can play an important role) and must be certain that adopting renewable energy sources brings them benefits (financial gains/savings, satisfaction), and not only costs and difficulties (change in habits, discomfort of use) [27,88,89,90]. On the other hand, the lack of comprehensive studies assessing the level of awareness of households about renewable energy in EU countries is considered a gap in the area of empirical research on renewable energy [91,92,93].

4.2.2. Recommendations

In order to eliminate the barriers to renewable energy development discussed above, it is worth recommending solutions that can contribute to effective energy transformation. These recommendations apply to all types of barriers and are presented in the publications selected below.

A. Carfora et al. [94], analyzing the complementarity of renewable energy development and green public policies in developed and developing countries, showed that in developing countries a multi-policy approach is required, where, for example, public capital subsidies are complemented by regulatory energy policies. In contrast, in developed countries a wide range of policies supporting renewable energy has already been implemented and, therefore, the adoption of additional green energy policies does not bring any other benefits. Therefore, the same policies do not fit different types of countries, as they are characterized by different levels of institutional and socio-economic development.

In turn, studies conducted in China, the Persian Gulf countries, as well as in continental Europe show that targeted incentives and strategies have proven to be constructive in encouraging the implementation of RES projects, with the most significant impact being R&D incentives, tax incentives, grid connection and tariff incentives, and market development incentives [27,95,96,97].

The research results of W. Przychodzeń and J. Przychodzeń [98] suggest that the factors stimulating the development of renewable energy sources (since the global crisis in 2007) were the strengthening of competition in the energy market and additional public financing.

Also Z. Abdmouleh et al. [99], in their research, focus on the factors that led to the successful implementation of renewable energy. However, it should be noted that not all of them will be applicable in every country. The authors noted that it is up to the policy makers to determine which barriers are the priority to be eliminated in a given country. Analyzing specific implementations of renewable energy in different countries, they provide examples of barriers that were faced and ways to overcome them. Thus, this review study provides information that aims to support better policymaking related to the development of renewable energy. Moreover, it presents how to collect and disseminate information on best practices that can help entities find better solutions for the development of renewable energy projects. These results are confirmed by A. Pitelis et al. [100], who claim that policy makers should focus on implementing those policy instruments that will prove to be the most effective for each type of technology. Their results suggest that demand-pull policies are likely to be more effective in supporting innovation in renewable energy technologies compared to other alternatives.

A review of motivational policies for the development of energy production from renewable sources was made by N. Kilinc-Ata [101] and G. Aquila et al. [102], who, using the examples of EU countries, the USA, and Brazil, identified a number of incentives for the development of RES. In the motivational policy for RES, the government’s participation is important by strengthening existing initiatives with short-term policies such as tax exemptions and tax reductions, especially taxes related to imports. In the case of Brazil, this results from the fact that RES projects in Brazil are largely dependent on technology developed abroad, which exposes investors to fluctuations in technology costs and exchange rates.

The effectiveness of renewable energy policies was also studied by G. Bersalli et al. [69]. Their analysis compared European policies (30 countries) with Latin American policies (20 countries) over a period of 20 years. As the research shows, the overall impact of promotional policies on renewable energy investments in both regions is similar and can be described as positive and statistically significant. Therefore, promotional policies are the main determining factor in both regions. However, tax incentives alone are insufficient to ensure the implementation of renewable energy technologies. The research showed that instruments such as feed-in tariffs or auction systems are essential for reducing the risk associated with renewable energy investments, even if some technologies, such as wind and photovoltaic energy, are already cost-competitive in several markets. A detailed analysis of specific structural elements of feed-in tariffs, auctions, and renewable energy portfolio standards conducted by F. Polzin et al. [103] shows that these instruments are most effective when they are designed to reduce the risk of RES projects while increasing the return on investment. K.S. Rogge and K. Reichardt [104] pointed out that in the energy transformation towards sustainable development, a combination of policies, understood as a combination of components, processes and features, i.e., a political strategy with its goals and main plans to achieve them, and a set of instruments with interacting policy instruments, plays an important role, which was confirmed by U. Bhattarai et al. [105]. The results of the analysis of 118 countries conducted by F. Hao, W. Shao [106] suggest that countries become more favorable to renewable energy when there are appropriate policies providing incentives to use renewable energy sources.

According to M. Mihaylov’s research [107], feed-in tariffs and net metering, which have contributed to the development of RES, do not take into account the issue of grid stability in the long term and do not provide adequate incentives for the production and consumption of green energy. Net metering guarantees that energy by prosumers is compensated until it does not exceed their own annual consumption. In turn, feed-in tariffs compensate the electricity introduced by prosumers at a fixed rate for a given period. As renewable energy generation is reaching a critical mass, they note the need to replace these widely used policies before they have a negative impact on stakeholders and the grid. As a way to improve these two policies, they propose making the remuneration of suppliers dependent not only on the (net) contribution of end users, but on the overall energy balance of the entire district. In their work, they also reviewed the state-of-the-art incentive mechanisms for renewable energy deployment, namely two auction mechanisms and PowerMatcher, a negotiation-based, digital currency-based approach for energy. They note that each of these approaches offers different revenues for the energy supplier and prosumers, a different unit cost of energy for consumers, and different overall support for green energy consumption.

The International Energy Agency in its report on net-zero emissions by 2050 [108] recommends that in order to move towards a zero-emission economy, governments should cooperate in a coordinated manner. The cooperation must take into account the differences in the levels of development of individual countries, because without international cooperation, achieving net-zero emissions will be more difficult and expensive for many rich countries, and it may prove impossible for developing countries. The necessity of international cooperation in the field of a zero-emission economy has been confirmed in the research by K. Hansen et al. [109].

4.2.3. Summary

Table 4. Barriers and challenges related to the implementation of renewable energy.

Barriers	Challenges
Economic: lack of financing possibilities for RES implementations lack of incentives for private investors	accelerated investments in system infrastructure increasing the scale of investments, including public funds—using incentives in the form of subsidies and tax regulation mechanisms (preferences for RES import duty/excise tax relief, VAT relief, tax relief/accelerated depreciation, production tax relief, tax holidays on income from production) imposing taxes on carbon dioxide emissions or energy on conventional energy sources instruments attracting demand —tax reliefs and rebates for consumers of new technologies, taxes on competitive technologies
Institutional: lack of comprehensive policies and regulatory frameworks	clear and transparent legal policies and procedures to attract investors updating policies and regulations through energy market regulations, streamlining the permitting process developing economic strategies for implementing renewable energy sources
Infrastructural/technical: lack of innovative infrastructure low expenditure on research and development of renewable energy	import of advanced technologies modernization of existing network infrastructure research and development on renewable energy sources (increase in financing from public sources, financing through VC, business angels)
Social: lack of acceptance by local communities	dissemination of information on the benefits of renewable energy sources (environmental, economic)

Source: own study based on [10,41,42,43,44,48,56,57,59,60,63,64,65,66,67,69,70,71,72,73,80,85,86,87,88,89,90,94,95,96,98,99,100,101,102,103,107,110].

summarizes the barriers and challenges related to the implementation of renewable energy identified in the literature, as well as the challenges that can be used to overcome these limitations.

5. Discussion

The research results presented in this paper clearly indicate that the subject of renewable energy in the context of sustainable development was and is a very important issue, as evidenced by numerous publications that emphasize the mutual relationship between these concepts—in other words, there is no sustainable development without energy obtained from renewable sources, and in turn, striving for sustainable development “enforces” the production and consumption of renewable energy. It follows that the production and consumption of energy from renewable sources is a necessity, as it has a positive impact on both the environment [19,21,27,28,30,31,32,111] and the economy [34,112,113,114], which in turn translates into the quality of life of society. An important advantage of renewable energy is also that it contributes to reducing the dependence of a given country on external (foreign) energy sources. This is particularly important for the “new” EU countries, i.e., those that joined in 2014 and later, because for many years they were largely dependent on fossil energy sources (gas, oil, coal) from Russia. When Russia attacked Ukraine, energy obtained from renewable sources became an important, if not the only, alternative to traditional energy sources. An example of countries that have focused on renewable energy are the three Baltic countries (Latvia, Lithuania, Estonia) [61]. It should be noted here that on 8 February 2025 Lithuania, Latvia and Estonia disconnected from the post-Soviet power system, and a day later, on 9 February 2025, they joined the Continental Europe Synchronous Area (CESA).

The research conducted also shows that despite the numerous advantages associated with the use of renewable energy, its development encounters a number of barriers, among which are most often divided into economic, institutional, technological and social barriers [65]. These barriers were confirmed, among others, in scientific papers presented at the Sustainable Energy and Environmental Protection (SEEP) conference, which took place at the University of Western Scotland in Great Britain in 2018 [82].

Both barriers and disadvantages of renewable energy, such as high initial costs, limited storage possibilities, geographical limitations, cause the level of use of renewable energy sources in individual countries to be very diverse. The impact of the level of barriers on the disproportions in the development of renewable energy between the “old” and “new” EU countries is discussed in [115]. The authors observed that in the “old” EU countries (e.g., Denmark, Sweden, Finland, Germany) the share of renewable energy in the energy balance is high, while in the “new” countries (e.g., Poland, the Czech Republic, Hungary), this share is much lower. Similar conclusions were drawn based on research conducted by Bąk et al. [116], which analyzed the impact of the use of energy from renewable sources on energy poverty. Both studies concluded that highly developed countries with a high level of GDP per capita are better prepared for energy transformation than countries with lower economic development.

The level of economic development, which translates into the quality of life of society, is an important premise for eliminating a very significant barrier related to the introduction of renewable energy, which is social acceptance. In rich countries, the costs related to the development of renewable energy are easier to accept than in countries where GDP per capita is at a lower level. This is primarily due to the fact that in poorer countries, the costs of living in relation to earnings are high and it is difficult to save money that could be invested, for example, in a heat pump or photovoltaics. This regularity is confirmed by the results of the research by Ropuszyńska-Surma and Węglarz [117], which, using the example of households in Poland, showed that most households do not want to install RES primarily due to the too high cost of installation (economic barrier) and the lack of technical possibilities of installing RES (technological barrier). In turn, Piekut [118] studied 28 EU countries in the years 2004–2019 in terms of the use of RES in households and it turned out that in relative terms, poorer European countries (e.g., Croatia, Romania, Bulgaria) have a higher use of RES in households than richer countries (e.g., Luxembourg, Belgium, the Netherlands). However, the economic barrier means that in poorer countries, cheaper solutions are used primarily (solid biofuels), while in richer countries—more expensive ones (heat pumps, solar technologies, biogases). In order to eliminate the economic barrier, it is necessary for individual countries to pursue appropriate pro-ecological policies, in which appropriately prepared programs supporting the financing of RES installations should play a significant role.

There is a possibility of using the integrated education for sustainable development in the promotion of renewable energy sources and, thus, increasing the level of its acceptance, which was widely discussed in [61].

6. Conclusions

The bibliometric analysis conducted in this article proved to be a valuable tool in scientific research. It allowed for a comprehensive assessment of the scope and progress of work on sustainable development in the context of renewable energy sources. Using the Web of Science database, key bibliometric indicators were identified, including the number of publications, the number of citations, the author’s country of origin and the journals in which works on the studied issues were published. It turned out that the majority of publications (21.9%) deal with the subject of finding a balance between sustainable economic growth and limiting environmental degradation. On the other hand, the least frequently analyzed issue was the implementation of climate goals in the context of sustainable development. This may be due to the fact that the implementation of this topic requires a review of many EU directives on environmental protection, which contain both target values and required directions of changes for indicators related to the protection of air, water, soil, or waste management. Moreover, the authors of the publications, when addressing issues related to sustainable development and renewable energy sources, in most cases indirectly refer to climate change. Therefore, it is difficult to indicate publications that directly concern only this issue.

The bibliographic analysis, together with an in-depth analysis of the content of the publications, also provided a basis for indicating research gaps concerning, among others, ecological education, energy poverty, or social acceptance of renewable energy. There is also a lack of comprehensive studies assessing the level of awareness of households about renewable energy in EU countries. Moreover, it was noted that in most of the analyzed publications, the research concerns energy from renewable sources in general, while there are significantly fewer articles focusing exclusively on a specific renewable energy carrier. There are also more articles in which the research concerned EU countries as a whole than publications addressing the topic of renewable energy in individual EU countries.

The research conducted by the authors allowed for obtaining answers to the research questions formulated at the beginning, and thus for achieving the specific objectives and the main objective. It was shown that the renewable energy sector in the EU and the Member States is developing dynamically, and the leaders in its development are the Scandinavian countries (Finland, Sweden), Austria, and Latvia. On the other hand, in the countries of Central and Eastern Europe, the pace of development of electricity from renewable sources depends on the source of this energy. In the years 2013–2023, almost 40% of electricity generated from renewable sources in the EU came from wind energy, almost 30% from hydropower, and 20% from solar energy, with solar energy being the fastest growing source of renewable energy. The development of renewable energy in EU countries is a consequence of its numerous advantages, which include primarily environmental benefits, i.e., reduction in greenhouse gas emissions, improvement of air quality, and reduction in dependence on limited fossil fuel resources, which in turn translates into minimization of the destructive impact of fossil fuels on the environment. An important advantage of renewable energy is certainly also the possibility of independence from external traditional energy sources and at the time of Russia’s invasion of Ukraine, the governments of many EU countries appreciated this advantage. However, despite the above-mentioned advantages, the development of renewable energy encounters a number of barriers, which are discussed in detail in this study, and at the same time recommending solutions that can improve the energy transformation process, especially in those EU countries where the pace of development of RES, is too slow (see Table 4).

The considerations contained in this article constitute a comprehensive analysis of renewable energy in the context of sustainable development in EU countries, thus, complementing the world literature in this field. The originality of the study is expressed in the fact that it allowed for the identification of barriers to the development of renewable energy together with recommending solutions that can improve the energy transformation process in many countries. Moreover, the added value of the article is to indicate the most popular research topics in this field, as well as to identify research gaps, the most important of which was the lack of publications in the field of ecological education, which, according to the authors of this study, is necessary to increase the level of social acceptance for renewable energy sources. An aspect of the presented work worth emphasizing is the broad review of literature defining the current state of obtaining energy from renewable sources, as well as a collection of opinions of different authors regarding the future direction of their development.

Renewable energy sources, alongside ICT and AI, are a symbol of the first two decades of the 21st century. Their dynamic development affects society and the economy on a local and international scale. The broad issues of renewable energy sources and sustainable development offer many opportunities for future research directions. They can focus on, for example, in-depth regional analyses, the relationship between renewable energy and the sustainable development goals (SDGs), or the impact of renewable energy sources on the environment. This article provides important knowledge to political, industrial, and academic stakeholders who are directly or indirectly involved in issues related to sustainable development and renewable energy sources. A detailed literature review has shown the dynamics of the presented works and their topics.

Our research also has some limitations. The first one is the knowledge base used in this study, limited to WoS. Future research should also include other publication databases, including Scopus. The literature analyzed by the authors is written in English, which is a significant limitation due to the fact that in many regions of the world, publications on this topic are written in French or Chinese, for example. Therefore, in future studies it would be worth considering a review of works in other languages. Furthermore, future studies could use, in addition to bibliometric tools, other methods, such as multidimensional data analysis or social network analysis, to reveal current research trends by analyzing newer publications, in addition to taking into account other important databases.