**1. Introduction**

The investigation of what drives economic growth and development is thematic and will never cease to be relevant in academia. The nexus between economic growth and energy consumption has been a significantly explored subject in academia over the years; for example, in recent years, this nexus was investigated by several researchers [1–9]. These and other studies pointed to a relevant relationship between energy consumption and economic growth, and the results obtained are of paramount importance in the development of policies and strategies according to the behavior of economic growth in the face of energy consumption.

After observing an increase in carbon dioxide emissions, research began to find evidence that related this increase with an increase in economic activity; therefore, we began to investigate the gap in which energy consumption was inserted, as in, [10–12]. Ref. [13] conducted a bibliometric review on this topic and concluded that there is a relationship of bidirectional causality between economic growth and CO2 emissions; thus, stimulating a reduction in emissions will reduce economic growth [13].

The existence of difficulty in reconciling economic activity and energy consumption with the conservation of the environment is clear, as is the need to encourage sustainable economic growth. Having said this, the present paper proposes to build a bibliometric review that takes into account studies investigating the relationship between renewable energy, economic growth and economic development nexus in order to understand which direction this field of study is taking.

The present research accessed the WoS and Scopus database to search keywords, titles and abstracts related to the terms renewable energy, economic growth and economic

**Citation:** Oliveira, H.; Moutinho, V. Renewable Energy, Economic Growth and Economic Development Nexus: A Bibliometric Analysis. *Energies* **2021**, *14*, 4578. https://doi.org/ 10.3390/en14154578

Academic Editors: Periklis Gogas and Theophilos Papadimitriou

Received: 30 June 2021 Accepted: 27 July 2021 Published: 28 July 2021

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development between the years 2008 and May 2021. The selection of articles used in the research was made through the PRISMA methodology. This research was also proposed to quantify the impact of the papers and journals published on the subject in that period, using some descriptive information to identify which journal(s) and which author(s) is the most relevant within the sample collected. Finally, an analysis was made, with the help of VOSviewer software, to find clusters and links between the terms used and the researchers.

The remainder of this study is structured as follows. Section 2 presents a brief literature review. Section 3 discusses the research methodology of the paper; Section 4 presents results, findings and discussion of this paper based on the study aims. Section 5 provides some concluding remarks, limitations of this study and suggestions for future papers.

#### **2. Literature Review**

In this section, a brief literature review on bibliometric reviews and systemic reviews is made. The authors of [14,15] set out to study the footprints of degradation. While one focused on environmental degradation itself [14], the other focused on the carbon footprint [15]. Studies differ methodologically; ref. [14] published a bibliometric analysis, while [15] published a systematic review. Ref. [14] researched the keywords "water footprint", "carbon footprint", "land footprint", "biodiversity footprint", "chemical footprint", "nitrogen footprint", "phosphorus footprint", "PM2.5 foot-print", "PM10 footprint" and "ozone footprint" in the Web of Science (WoS) database for the period 1986–2019 after screening processes reached a sample of 4352 articles. The results indicate that the U.S. and China are the countries that have conducted the most research on the subject in the period aforementioned and are those with the highest cooperation among themselves. In addition, it was emphasized that "water footprint" and "carbon footprint" are the most studied terms in relation to the others used in the research. Finally, the authors concluded that the most recent research focuses on the carbon footprint related to supply production chains, greenhouse gas emissions, water consumption in agriculture and environmental issues related to construction [14]. In the study proposed by [15], we used the same database, except for the 1992–2019 interval, and only searched the keyword "carbon footprint", obtaining a sample of 7450 articles. The results indicate that research on the subject began to grow in 2008, and four topics were "international trade", "life cycle assessment", "ecological footprint", and "supply chain". There was also a significant interaction between the US and European Union (EU) research; however, in recent years, research from China has been increasing and standing out. The Journal of Cleaner Production is the most prominent. Finally, research in Economic and Political Economics seems to be the most recent ascending [15] theme. Ref. [16] developed a systematic review on carbon leakage with the following questions: What are the generation channels and the factors of the leakage? What methodologies are used to evaluate the leak? Which topics need more attention to formulate more effective climate policies? [16]. The research used the keywords "carbon leakage" and "emission transfer" in the WoS database for the period 2000–2020, with screening techniques reaching 407 articles for research. The researchers concluded that many studies have focused on the loss of competitiveness in the intense emission sectors, caused mainly by international trade, and there is not enough debate about the negative leak channel. In addition, the authors point out the absence of quantitative methodologies for carbon leaks [16].

With the intention of providing an overview of the work performed on the Environmental Kuznets' Curve (EKC), ref. [17] proposed a bibliometric analysis. Using the WoS database, he analyzed the publications made in the period of 1999–2010, with the PRISMA approach, and reached a sample of 1775 articles to study. The results of the study indicate that research has grown exponentially in recent years and that China, the U.S., Turkey and Pakistan are the countries with the highest academic publication on the subject. In addition, the authors surveyed the journals that published the most in that period, which are Environmental Science and Pollution Research, Journal of Cleaner Production, Ecological Economics and Energy Policy. The author with the most publications is Muhammad Shahbaz [17]. Furthermore, on the topic of EKC, [18] used the WoS database to conduct a

study of publications on the subject in the last two decades (1999–2019). From a universe of 59,225 documents, 2384 were investigated in this research. The results found by the authors, based on co-citation, indicate that the most relevant journal on this topic is Ecological Economics; in addition, of the ten most relevant journals, Elsevier publishes seven. The countries with the highest number of citations are China, the USA and Turkey. The same order was obtained by [17]. The most influential researcher is Muhammad Shahbaz, with the same result obtained by [17]. It is no coincidence that the most relevant institution is the Beijing Institute of Technology, where Muhammad Shahbaz is a professor [18]. Moreover, [19] proposed a systemic and bibliographic review on industry 4.0. The study used two databases for the survey of Scopus as well as WoS articles published until 2020. The terms used for research were "Industry 4.0", "Industrie 4.0" and "Fourth Industrial Revolution", following PRISMA protocols, and a sample of 745 articles were obtained. The authors concluded that industry 4.0 is motivated by profit; the value of digital transformation is materialized as corporate profit. In addition, the authors highlighted factors that can determine success or failure, which depend on favorable conditions such as governmen<sup>t</sup> incentives and an abundance of resources for the digital transition in Industry 4.0 to be achieved [19].

With the objective of detailing the stage and the current research trends on Thermal Energies Storage (TES), [20] elaborated a bibliometric analysis on the subject. The Scopus database was used for the research that used all available coverage until 21 September 2020. The authors divided the results of the research into three categories, including buildings, districts, and roads and bridges [20]. As far as buildings are concerned, the results indicated that it is and the most studied category. The USA was the country to publish the first relevant studies on the subject, and the most researched line is the demand for cooling by optimized control techniques. While in Europe, of latent heat thermal energy storage through passive techniques and demand managemen<sup>t</sup> strategies, in China, there is a focus on material study, and economic analysis seems to be the trend of the most recent studies for buildings. Studies on TES applied to districts began to increase in 2013 and are led by Europe. TES at the district level was investigated at the system level, mainly applications of solar systems and cogeneration systems. The most recent studies have investigated economics and techno-economic. Finally, studies applied to roads and bridges do not attract many researchers. Norway, Japan and China are the countries with the most Publications [20]. Ref. [21] conducted a bibliometric study between 2000 and 2019 on TES in order to understand the trend and future of this field of research. The authors' analysis concludes that latent-heat TES has been the focus in recent years, but thermochemical TES and its hybrid TES technologies appear to be the next focus of researchers [21].

A bibliometric and systematic review was proposed by [22] to understand the standards of key performance indicators (KPI) and multicriteria decision-making models (MCDM/A) in the context of renewable energy technologies (RET). The following questions were raised: "Is there a pattern in the use of performance criteria to select and assess RET performance?"; "Is there a pattern in the use of multicriteria models for decision making to select and assess RET performance?". To find these answers, 142 articles from the WoS database were selected between 1998 and 2019. The authors concluded that there is a growing trend in this research, mainly from 2015. According to the authors, the results of this study demonstrated a preference in the use of synthesis models rather than overlap, the importance of considering political and technical indicators beyond those related to the Triple Bottom Line in decision-making and the importance of MCDM/A in achieving the sustainable development goals of the United Nations agenda [22].

A mapping of a 21st-century problem, poverty energy, was proposed by [23]. Thus, a bibliometric analysis was made using the Web of Science database, and for the 1999–2019 temporal sample, they obtained 1018 articles in the sample. The results show that 2003 was the founding year of energy poverty research. Nine hundred eighty-two institutions developed research on the subject. In addition, the results indicate that the largest cooperation occurred between the UK, USA, Australia and Italy. Among the periods, Energy Policy

publishes on the subject for the longest period, while Renewable and Sustainable Energy Reviews publishes the studies with greater influence; Sovacool is the researcher with the highest number of publications and the most influential. Finally, the authors highlighted four areas that should be research trend in the coming years: energy poverty in developing countries, impacts of energy poverty on vulnerable groups, root causes of energy poverty and consequences of emission reduction policies [23].

#### **3. Materials and Methods**

In this section, we explain the database, period and methodology applied in the selection of the investigated articles and the techniques applied for analysis. There are several databases for scientific document searches, for instance, the Web of Science (WoS) and Scopus. This investigation chose to use the database provided by WoS and Scopus for the period 2008 to 21 May 2021. The year 2008 is the first year of commitment to reducing carbon emissions of the Kyoto protocol subscriber countries; this first cycle being finalized in 2012, the chosen period covers the years of the first cycle and the subsequent period.

The first step of this investigation was the choice of the sample, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology proposed by [24]. The PRISMA methodology is a guideline developed to deal with unsatisfactory systematic reviews, which focuses on making the research transparent; therefore, the researcher needs to be aware of the purpose of the review, what the procedure was, and finally, what the findings were [24].

According to [24], the PRISMA methodology was developed to be applied in systemic reviews that assess the effects of interventions in the health area. The PRISMA approach provides guidance that contributes to a methodological improvement to identify, evaluate and synthesize studies; this technique consists of applying a checklist with 27 items in order to have a more accurate screening. Although developed to be applied in the health area, the checklist is relevant and applicable for systematic reviews with mixed methodologies, which include quantitative and qualitative studies [24], a scenario faced by this research.

First, all the documents in the Web of Science (WoS) database related to the three terms of the research (Renewable Energy, Economic Growth and Economic Development) were researched for the period 2008 to 21 May 2021. Immediately, 3382 documents were identified. When applying the procedures, only open access documents were considered; this limited the search to 1.025, excluding 2357 documents. Then only the following areas of research, Environmental Science, Energy Fuels, Environmental Studies, Economics, Management and Business, thus eliminating 426 documents and having 599 documents. Then, the type of documents and language was limited, taking into account only scientific articles and in the English language, leaving 428 articles with the possibility of making the final sample. Finally, titles and abstracts were analyzed; in this stage, 317 articles were disregarded, thus leaving 111 to make up the Web of Science sample. Figure 1 summarizes the screening process.

Second, all the papers in the Scopus database relating to the words Renewable Energy, Economic Growth and Development Economic were identified. The search with these words was directed in keywords, title and abstract, resulting in 2836 identified documents. Following the identification was the screening stage where only open-source documents were chosen to be analyzed, resulting in 790, so there was a reduction of 2046 documents. The second stage of screening was to exclude the research areas that are not related to the focus of the investigation of this research, considering only the following fields of study: Environmental Science, Energy, Social Sciences, Economics, Econometrics and Finance, and Business, Management and Accounting. With this restriction, 377 documents were eliminated, leaving 413 with the possibility of entering the study. Then, we limited the types of documents. We took into account only articles, finding 300 articles. In addition, these were limited to the English language, which resulted in the exclusion of 9 articles, making 291 eligible. Finally, an analysis was made of the abstracts, titles and keywords of these 291 articles to determine which ones would be considered for the investigation of this

systematic review, based on the information found. Ninety-two articles were disregarded, so 199 articles were considered for analysis, as can be seen in Figure 2. The protocol applied to the Scopus database can be found in Appendix A of this research.

**Figure 1.** Identification of Studies Via Web of Science Database.

The eligibility of the articles used in this research was mirrored in the strategy applied by [13]. In the stage of determining the eligibility of the articles, the title, abstract and keywords of the individually selected articles were reviewed. In this final stage of screening, we identified the articles that could be part of the study sample. Having exposed this, the articles included in the research explore the link between economic growth, renewable energy consumption and economic development. It should be emphasized that at this stage, only scientific articles were taken into account, so documents such as thesis, dissertations, articles published in a non-English language, editorial notes, books, book chapters, among other types of documents, were disregarded. Finally, it was possible to obtain the 199 articles used in this research, which relate to the keywords in question, from a sample of 74 international journals between 2008 and 21 May 2021.

This research chose to work with the Scopus database due to its grea<sup>t</sup> coverage and multidisciplinary. In addition to being peer-reviewed, updated frequently and has resources that assist researchers in the development of work. According to [25], the biggest advantages of the Scopus database are the inclusion of open access articles, tools to find authors, a wide catalog of scientific and technological journals, automatic generation of h-index, more content published in Europe compared to WoS [25].

The screening criterion applied in the Web of Science (WoS) database, which final filter according to the Prisma technique, shows a sample of 111 documents; moreover, 50 articles that represent 45% of the searches found in the WoS database are also listed in the Scopus database.

**Figure 2.** Identification of Studies Via Scopus Database.

After defining the investigated studies, this research analyzes the information of the articles, considering some indicators: number of publications, h-index and citations, as was performed in [26]. However, it is important to emphasize that the literature does not ye<sup>t</sup> have an accurate and conclusive methodology to evaluate articles, journals, and so on, let alone be able to determine their value. This field of research, which tries to measure the value of an article, the researcher or even the institution, is criticized. A criticism pointed out by [26] assumes that an article published in a journal of greater relevance should have a higher value than one published in a median journal, but this is a challenge since each article, regardless of where it is published, will be assigned the same value [26]. The databases, trying to work around these difficulties (for example, the Scopus database), have three metrics that are based on the citations received to assign quantitative values, whether to the author, article, journal or institution, they are: CiteScore (CS), SCImago Journal Ranking (SJR) and the Source Normalized Impact per Paper (SNIP), while, in the WoS database the metrics are available in the Journal Citation Reports (JCR) from Clarivate Analytics

The CiteScore from Scopus is not similar to the impact factor calculated by JCR of the Web of Science (WoS). The difference occurs only in the period used to make the calculation. The CS considers the number of citations in the last 3 years and divides these by the number of publications in the same period, while the ones calculated by WoS are based on the interval of the last 2 years. Nevertheless, according to [26], these metrics are not 100% reliable since it is possible to circumvent them using self-citations [26]. Another Scopus metric used to rank journals is the SJR, which measures the weighted citations received by the journal; the weighting of the citations takes into account the subject field and the prestige (SJR) of the journal it cites.

As a certificate that auto citations are a problem for these metrics, the same problem should be taken into account when the absolute number of citations is considered as a metric. However, in this case, when dealing with already conceptualized studies, this problem tends to be less significant since it is expected that reputable articles are more cited. Intuitively, there is a number of citations that is much higher than the number of articles [26] since they are considered as references. Hereby, the number of citations can be taken into account with the purpose of measuring the influence of an institution, author or journal [26]. Nonetheless, there may be flaws, for example, a grea<sup>t</sup> article recently published and that has not ye<sup>t</sup> become popular or even research conducted in a very specific scientific field.

Finally, there is the h-index, proposed by [27], which combines the number of publications and citations. Taking this research as a reference, which has an h-index of 34, this tells us that at least 34 articles published in the period investigated received 34 or more citations. Just as the other metrics, it also has criticisms. For instance, an extreme case pointed out by [26]: if a researcher publishes more than 100 articles and three received more than 1000 citations, while the rest are not cited, the index of this researcher will only be three [26]. Instinctively, it is possible to conclude that this hypothetical researcher has an academic relevance significantly higher than three. Despite the criticisms, this index is useful and relevant in academia; therefore, it is appropriate to the scope of this research in the criterion of evaluating the relevance of research, researcher, journal or institution.

In addition, with the help of VOSviewer software, textual analysis is made in order to identify the relationships between articles, keywords and researchers in the Renewable Energy, Economic Growth and Economic Development theme. The VOSviewer software allows for a relationship network construction between the articles published in the specified period.
