R E V I E W P A P E R
Prospecting technologies for photovoltaic solar energy:
Overview of its technical
‐commercial viability
Priscila Gonçalves Vasconcelos Sampaio
1| Mário Orestes Aguirre González
2|
Rafael Monteiro de Vasconcelos
2| Marllen Aylla Teixeira dos Santos
2|
Priscila da Cunha Jácome Vidal
1| Jonathan Paulo Pinheiro Pereira
3| Everton Santi
21Exact and Ground Science Center, Federal University of Rio Grande do Norte, Natal, Brazil
2Technology Center, Federal University of Rio Grande do Norte, Natal, Brazil 3
Electrical Department, Federal Institute of Rio Grande do Norte, Mossoró, Brazil
Correspondence
Priscila Gonçalves Vasconcelos Sampaio, Exact and Ground Science Center, Federal University of Rio Grande do Norte, Natal, Brazil.
Email: [email protected]
Funding information
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Grant/Award Number: 001
Summary
There are many technologies that may emerge and eventually disappear over the years. This fact makes the monitoring of technological trends as well as the anticipation of the direction of technological change paramount. This arti-cle aims to carry out the prospection of technologies, focusing on its technical‐ commercial viability, for solar photovoltaic energy. The research method had a qualititative‐quantitative approach with application of the Delphi technique. In the conduction of the Delphi technique, seven steps were followed, ranging from the selection of the specialists to the considerations of their opinions regarding the future of nine photovoltaic technologies. The results of the research indicate that in 2020, the cells monocrystalline, multicrystalline, and amorphous silicon; cadmium telluride; indium/copper selenide, indium, and gallium diselenide; and multicompound III‐V cells will have technical and commercial viability and that dye‐sensitized silicon nanowire and carbon nanostructure‐based cells will not be viable. For the year 2025, monocrystalline and multicrystalline silicon cells and those of multicompounds III‐V will still be technically and commercially viable. Silicon nanowire; amorphous silicon; cadmium telluride; indium/copper, selenium, and gallium diselenide dye‐ sensitized cells; and organic photovoltaic cells, including those based on carbon nanostructure, may be viable. This study is important, because the tech-nological prospecting of the photovoltaic cells determines the possible trajecto-ries of these cells, in a way that helps the companies of the sector to anticipate the strategic scenarios, thus facilitating the decision making process.
K E Y W O R D S
Delphi technique, photovoltaic solar energy, technical‐commercial viability, technological prospecting
1 | I N T R O D U C T I O N
Technological knowledge is indispensable and extremely important for the success of innovation management.
New and emerging technologies often appear on the edge of different technological fields.1 Analyses of emerging technologies and their implications are vital for the econ-omy, society, and business.2,3 Human society needs to
DOI: 10.1002/er.4957
consider, based on social planning and a global perspec-tive, the use of new technologies to achieve sustainable development.4,5
Similarly, companies or governments with the goal of allocating investments in product and process innova-tions, all of which seem attractive, may prefer to invest in those that are more likely to make faster progress. Investing in research and development for a product that employs new technologies is a challenging issue for busi-nesses and governments especially at the critical time of deciding the degree of resource allocation, if any.6-8
There is a consensus in the scientific community and business environment of the strategic importance of tech-nology in generating value for the companies and net-works in which they operate. Managing technology for the benefit of your business requires effective processes and operating systems to ensure that existing technology resources are aligned with your needs now and in the future. Moreover, the impact of changes in technology and markets needs to be assessed in terms of potential threats and opportunities.9-11
There are many technologies that may emerge and eventually disappear over the years.12 This fact makes the monitoring of technological trends as well as the anticipation of the direction of technological change par-amount.13 The high levels of uncertainty and risk are among the main obstacles to decision making in the cur-rent economic and political situation. Prospective studies are extremely effective tools for building long‐term strate-gies and policies to promote economic, political, and social sustainability. They also serve as a means of assessing the impact of technologies and markets in busi-ness. These studies seek to understand the forces that guide the future, as well as to promote transformations, negotiate spaces, and give direction and focus to changes.9,14-16 Prospective technology studies are devel-oped according to their objectives, and the results of these studies are translated into policy documents or academic publications.17
In view of the above, this article aims to present the prospecting of technologies for photovoltaic solar energy giving an overview of their technical‐commercial viability for the years 2015, 2020, and 2025. To this end, the Delphi technique was applied. In this sense, this study is impor-tant, because the technological prospecting of the photo-voltaic cells determines the possible trajectories of these cells, in a way that helps the companies of the sector to anticipate the strategic scenarios, thus facilitating the decision making process.
The article is structured in five sections. Section 1 looks at the introduction, and then Section 2 deals with the theoretical basis for prospective technology methods. Section 3 exposes the search method. The fourth section
describes the Delphi technique. In the last section, we conclude on the subject, its limitations, and suggestions for possible future studies.
2 | P R O S P E C T I V E
M E T H O D O L O G I E S
Systematic processes to analyze and produce judgments about emerging technology characteristics, development paths, and potential impacts in the future are covered in the technology future analysis (TFA), concept that brings together several methodologies of technological prospection.14,18 In this sense, TFA aims to integrate, among others, concepts of technology foresight predomi-nant in the public sector and technology forecasting, which is linked more to demands of the private sector.
Kupfer and Tigre19 and Mayerhoff20 define these methodologies as being
• Technology forecasting: realization of projections based on historical information and trend modeling and
• Technology foresight: anticipation of future possibili-ties based on unstructured interaction between spe-cialists, each of them based exclusively on their knowledge and subjectivities.
Forecasting is a more deterministic approach, in which the future is seen as the extrapolation of the past. The forecasting method provides a probabilistic prediction of the future development of current technologies by quanti-fying and extrapolating trends.21The technology forecast-ing is the process of describing the emergence, performance, characteristics, or impacts of a technology at some point in the future.2
Forecasting is important for understanding technical emergence and applying this knowledge to take preven-tive action in research and development and in strategic management of the company. Forecasting is most suc-cessful when there is the integration of diverse and effec-tive sources of information to produce a convincing and global view of possible futures.22,23
Foresight is based on a rational and explicit methodol-ogy of qualitative modeling, allowing to combine existing knowledge with expert opinion through its interaction. The overall objective of a foresight activity is to improve the relationships between scientific and socioeconomic development activities to develop visions for policy for-mulation and strategy coordination.24
However, foresight can present disadvantages; that is, it may not solve some social, economic, or environmental problems, nor can it impose consensus where there are
deep differences between stakeholders. It is not yet a fast remedy for urgent problems, because it requires long‐ term analyses and expert networks that do not produce immediate results.25
2.1 | Main prospecting techniques
There are several methods of analysis and techniques of technological prospecting that, due to possible fragilities arising from individual perceptions about an uncertain future, can be used more as complementary and less as alternatives.21 The quality of the results of prospective studies is strongly linked to the correct choice of the tech-nique to be used.10,14,26
Determining the technique that best reflects the char-acteristics of an organization is a complex and challeng-ing problem; therefore, Esmaelian et al27 proposed a methodology for evaluating technological prospection techniques that facilitates managers' decision making as to which technique best suits their organization.
It is common for a prospective study to involve the use of multiple methods or techniques, quantitative and qual-itative, in order to complement the different characteris-tics of each one, seeking to compensate for the possible deficiencies brought about by the use of isolated niques or methods. The choice of methods and tech-niques and their use depend intrinsically on each situation. Consideration should be given to specific aspects of the area of knowledge, application of the tech-nologies in the regional or local context, governmental or business, scope of the exercise, time horizon, cost, objec-tives, and underlying conditions.10,14,26
The methods and techniques of prospecting are classi-fied into families: creativity, descriptive methods and matrices, statistical methods, expert opinion, monitoring and intelligence systems, modeling and simulation, sce-narios, trend analysis, and decision evaluation systems,2 as shown in Table 1.
Most of these techniques are known while some were generated for other purposes and later used in prospective studies.14The authors add that creativity is imperative in prospective studies, since it is necessary to increase the ability to visualize alternative futures, to have new ideas and to encourage a new perception pattern, thus avoiding preconceived views of problems and situations.
Descriptive methods and matrices, in turn, can be used to increase creativity and allow the identification of alter-native futures. This family depends on experts, good data sets, and good structures and understanding of modeling and information and communication technologies.14,26
Statistical methods refer to models that seek to identify and measure the effect of one or more important
independent variables on the future behavior of a depen-dent variable. Among the techniques that involve statisti-cal methods is patent analysis, which is an agent that promotes innovation and assumes that the growing inter-est in emerging technologies will be reflected in increased research and development activities. This, in turn, will lead to increased patent filing. Thus, it is believed that emerging technologies can be identified by examining the patterns of patent applications in certain fields.14,26
The expert opinion method is based on what people perceive as feasible, according to their beliefs and limited imagination. Monitoring and intelligence systems are basic sources of relevant information and therefore are commonly used in prospective studies to observe, check, and update developments in an area of interest defined for a very specific purpose. Technological competitive intelligence, however, emerged in the 1990s as a new form of prospecting to replace classical monitoring thus expanding its scope and performance.14,26,28
Modeling and simulations allow one to perform tests and verify how the variables involved behave, thus allowing the analytical treatment of large amounts of data.14Scenarios, in turn, make it possible to systemati-cally order perceptions about alternative future environ-ments, based on combinations of conditionings and variables. It incorporates a wide range of quantitative and qualitative information that helps managers in deci-sion making. However, it may be difficult to obtain the desired information.21,26
Trend analysis builds a feasible scenario based on the assumption that past patterns will be conserved at future times, particularly in the short term, and, when there are variations in the data, provide a more vulnerable analysis in long‐term forecasts. Regarding the evaluation and deci-sion methods, they assist in setting priorities when there are a large number of variables to be analyzed.14,21,26
2.1.1 | Delphi technique
The Delphi technique was developed by the RAND Cor-poration in the 1950s by Olaf Helmer, Norman Dalkey, Ted Gordon, and associates under funding from the United States Air Force as a technique to apply expert input systematically using a series of questionnaires with results feedback after every round.12,29-34
The name of the technique originates from Greek mythology, where in the oracle of Delphi, which was ded-icated to the God Apollo, the ancient Greeks questioned the gods. In the oracle, it was possible to obtain answers and prophecies made by the priestesses of Apollo in trance state. All that was said by the priestesses was regarded as absolute truth.35
TABLE 1 Classification of methods and techniques for analysis of future technologies
Family Method/technique
Creativity Brainstorming (brainwriting; nominal group process [NGP])
Creativity workshops (future workshops) Science fiction analysis
TRIZ
Vision generation
Descriptive methods and matrices Analogies
Backcasting
Checklists for impact identification Innovation system modeling Institutional analysis Mitigation analyses Morphological analysis
Multicriteria decision analyses (data envelopment analysis [DEA]) Multiple perspectives assessment
Organizational analysis Relevance trees (futures wheel)
Requirements analysis (needs analysis attribute X technology matrix) Risk analysis
Roadmapping (product‐technology roadmapping)
Social impact assessment (socioeconomic impact assessment) Stakeholder analysis (policy capture assumptional analysis) State of the future index (SOFI)
Sustainability analysis (life cycle analysis) Technology assessment
Statistical methods Bibliometrics (research profiling; patent analysis, text mining) Correlation analysis
Cross‐impact analysis Demographics Risk analysis Trend impact analysis
Expert opinion Delphi (iterative survey)
Focus groups (panels; workshops) Interviews
Participatory techniques
Monitoring and intelligence systems Bibliometrics (research profiling; patent analysis, text mining) Monitoring (environmental scanning, technology watch)
Modeling and simulation Agent modeling
Causal models
Complex adaptive system modeling (CAS) (chaos) Cross‐impact analysis
Diffusion modeling
Economic base modeling (input‐output analysis) Scenario‐simulation (gaming; interactive scenarios) Sustainability analysis [life cycle analysis]
Systems simulation (system dynamics, KSIM) Technological substitution
Technology assessment
Scenarios Field anomaly relaxation method (FAR)
Scenarios (scenarios with consistency checks; scenario management) Scenario‐simulation (gaming; interactive scenarios)
Trends analysis Long wave analysis
Precursor analysis
Trend extrapolation (growth curve fitting and projection)
The Delphi technique is often adopted to conduct pro-spective technology activities in order to overcome vari-ous challenges in development and planning with science, technology and innovation.36 According to Linstone and Turoff,37 (p3)Delphi consists of a “method for structuring the process of group communication as long as this process is effective in allowing a group of individuals as a whole to share a complex problem.”
One of the benefits of this method is the ability of indi-viduals to participate in a group communication process asynchronously at times in places convenient for them.29 It also presents as advantages the individual and collec-tive reflection on the topics discussed, favors the integra-tion and synergy of ideas and visions among specialists, and adds knowledge to the process. However, the tech-nique has some disadvantages, such as the difficulty in preparing the questionnaire, since it has to be clear and objective and requires in‐depth knowledge of the topic; difficulties in answers due to unanswered questionnaires and withdrawal during the rounds; and long deadlines for the execution of the technique, since time is required for the preparation of the questionnaire, its application, tabulation and analysis of the answers, reformulation and reapplication in the subsequent rounds, and prepara-tion of the conclusions and final report.38
The Delphi technique is based on the assumption that group decisions are more valid than individual judg-ments. Delphi provides the interconnection and agree-ment of opinions and predictions among experts on a given topic with the ability to evaluate complex issues during several rounds of application.33 In addition to seeking consensus, this technique also aims to obtain the, according to Oliveira et al,35(p10) “future forecast, based on a qualitative/quantitative method of collecting opinions/data based on the knowledge of a specific group of people specialized in the subject studied.”
Corroborating with this idea, Teixeira21(p20)shows that the Delphi technique “constructs a vision of the future
based on qualitative information, using the subjective logic and judgment of people with great knowledge and familiarity with the theme in question.” The author emphasizes that, in the search for consensus, throughout the application of the technique, there may be differences between specialists in the same area.
Characteristics of the technique are anonymity, itera-tion, controlled feedback, and statistical treatment of responses.29-32,39,40
Anonymity means that there is no persuasion and socio‐psychological–political–cultural pressure among the participating members in order to guarantee equality of expression and ideas, as well as guarding trends and avoiding distortions. Iterations coupled with controlled feedback allow each participant to learn from group responses in previous rounds and modify their own point of view after knowing what others think.31,35The statisti-cal treatment of the judgments, through descriptive statis-tics (mean, median, standard deviation, and interquartile range) as well as percentage calculations, is used to com-pile the answers and provide feedback to the experts on each round.31
The Delphi technique consists in applying the ques-tionnaire in successive rounds and as many as are neces-sary to obtain the consensus of the answers among the experts.31,41,42
With the Delphi technique, it is possible to collect data provided by the participating experts and to achieve con-vergence of opinions for a certain theme.43 Consensus is determined by measuring the variation in limb responses throughout the rounds. The reduction of the variation between the rounds is usually achieved due to the feed-back process between the iterations. The greater the reduction in the standard deviation or the increase in the percentage calculation indicates that a greater consen-sus was reached.41
The Delphi technique has already been used in the studies of Myllylä and Kaivo‐Oja,33 where the TABLE 1 (Continued)
Family Method/technique
Trend impact analysis Evaluation and decision systems Action (options) analysis
Analytical hierarchy process (AHP) Cost–benefit analysis (monetized and other) Decision analysis (utility analyses)
Economic base modeling (input‐output analysis) Relevance trees (futures wheel)
Requirements analysis (needs analysis, attribute X technology matrix) Stakeholder analysis (policy capture, assumptional analysis)
combination of the Boston Consulting Group (BCG) with the Delphi technique was used to analyze the future port-folio of products and services of the Finnish maritime industry. In Prokesch et al,44a market forecast was made in Obrecht and Denac43 for a prediction of sustainable energy development. In Gary and Von Der Gracht,45the Delphi technique was applied in the analysis of the future of prospective professionals. In Förster,46 it was used in identifying technologies and processes that may be rele-vant to sustainable production in the German automotive industry in the future.
In Adnan et al,47the Delphi technique was applied to joint venture projects. Hansen et al48 used two comple-mentary approaches, one of them the Delphi technique, to explore the challenges for successful recruitment of family caregivers through social media. Mili and Bouhaddane49 provided a forecast of global supply and demand for olive oil.
3 | R E S E A R C H M E T H O D
The research is characterized as applied.50 The type of logical argumentation is characterized as inductive,51 and according to its objective, it is exploratory and descriptive.52 The scientific approach is quantitative‐ qualitative,53 and a survey (Delphi) is technical procedure.52
The research was carried out in three stages, according to Figure 1.
The first stage consisted of a literature review on methods and techniques of technological prospection and photovoltaic technologies for solar energy. Photovol-taic technologies for solar energy were identified through systematic literature review (RBS). The articles that com-prised RBS were captured through the Metabusca tool of the Periódicos CAPES portal (Coordination for the Improvement of Higher Education Personnel in Brazil)
using the following keywords: “solar energy,” “sun power,” “photovoltaic solar energy,” and “photovoltaic cells.” This portal brings together more than 102 bases such as Scopus, Web of Science, among others. In the construction of RBS, 118 articles, which contained in their title or summary these keywords, were used. No fil-ter was used to limit the years of the search, which was made among all texts published until 31 December 2014. To reinforce technology identification, a patent search on photovoltaic technologies was performed in Thomson Derwent's Derwent Innovations Index (DII) databases. This database was chosen because of the worldwide cov-erage features in patent documents. This patent search and analysis system present patent information extracted from 40 worldwide patent‐issuing agencies organized into three categories, or sections: chemical, engineering, and electrical and electronic. It also has cited references and citations received from six major patent‐issuing bodies (PCT Patent Cooperation Treaty, United States, Europe, Germany, Great Britain, and Japan) since 1973. The search strategy was based on the association of photovol-taic cell‐related keywords in the topical (TS) field, taking into consideration the World Intellectual Property Orga-nization (WIPO) International Patent Classification. The keywords were searched in the English language (base language), corresponding to TS = (photovoltaic module * or photovoltaic panel * or photovoltaic cell *). The sym-bol * was used as Wildcard for the purpose of retrieving radical variants of the word cell, and as an operator OR was used to retrieve summaries that had any of the words between this operator. The time interval of the retrieved documents was from 2004 to 2013. These documents were exported in a.txt file, with all fields provided by the DII database (inventor, title, abstract, patent number, interna-tional patent classification, etc).
As a result of the first step, the Delphi technique was selected for the prospective study, as it is considered the most relevant among the consensus‐based prospecting techniques and also because this method seeks a conso-nance among experts on technological development, since, for the conducting the research, time and resources were restricted not allowing structured methods of inter-action between those involved. Also as a result of the first stage, nine photovoltaic technologies were identified (Table 2).
It is important to note that perovskite is not only used as a sensitizer in the dye‐sensitized solar cell. Due to advances in research on the use of perovskite in the gen-eration of photovoltaic solar energy, recent studies indi-cate that perovskite can be used as semiconductor giving rise to photovoltaic solar cells of perovskite, which reached high levels of efficiency (around 22%). However, the toxicity of lead and the operational stability caused FIGURE 1 Search procedure
TABLE 2 Photovoltaic technologies for solar energy
Technology Description
Monocrystalline silicon They offer excellent conversion efficiency, as long as they have high manufacturing costs, higher energy requirements during their life cycle, longer energy return time, and require the use of very pure materials (solar grade silicon) and perfect crystal.54-60
Polycrystalline silicon The cost of production is lower, less efficient than monocrystalline, has a better aesthetic appearance, consumes less energy during its life cycle, shorter energy return time, less greenhouse gas emissions, requires less energy in the crystal structure need not be perfect.54-60
Silicon nanowires If compared with monocrystalline and multicrystalline cells, it needs less silicon to obtain the same amount of absorption. The energy losses that occur when light passes through a photovoltaic cell without being absorbed is less. They allow the use of silicon of inferior quality to solar grade silicon. They can be produced with excellent electrical characteristics. These advantages can substantially reduce the cost of producing solar cells based on silicon nanowires by keeping these cells competitive.61
Amorphous silicon It has low efficiency due to the initial degradation induced by light. This technology differs from crystalline silicon in that it has a larger gap (1.7 eV) while that of crystalline silicon is 1.1 eV.56,62,63
Cadmium telluride Known for having an ideal gap (1.45 eV) and high coefficient of absorption of the solar spectrum. However, it has the problem of cadmium toxicity and the scarcity of tellurium56,62,64-66. Copper indium diselenide or copper indium gallium/copper
indium–gallium diselenide or copper indium gallium selenide
It contains semiconductor elements of groups I, III, and VI of the periodic table, which are beneficial because of their high optical absorption coefficients and their electrical characteristics that allow device adjustment. It presents problems related to degradation under wet conditions and the scarcity of indium in nature56,57,65,67. Organic photovoltaic cells They are constructed from thin films of organic semiconductors, such as
polymers. They are composed of small molecules such as pentacene, polyphenylene vinylene, copper phthalocyanine (a blue or green organic pigment), and carbon‐based nanostructures (fullerenes, nanotubes, and graphene). The manufacturing process is less expensive compared with traditional silicon, since it uses low‐cost material and high production throughput. However, they have limited durability and low conversion efficiency due to the large energy gap.56,59,68-74
Dye‐sensitized solar cell They are formed by organic and inorganic materials. The cost of manufacturing compared with other technologies is reduced due to the use of impure raw materials and simple cell processing. It has stability over time. They use low‐cost titanium dioxide (TiO2) in their manufacture compared with silicon that is used in conventional solar cells. Cells based on organometallic dyes, such as ruthenium and porphyrins (zinc complexes), have shown excellent conversion efficiency from solar to electric. Difficulty of synthesis and purification of ruthenium and porphyrins. Limited ruthenium availability. Semiconductors of the perovskite (CH3NH3) PbX3organometallic trialkyl class, where X may be iodine, bromine or chlorine) may be used as light collecting components in dye‐sensitized solar cells to give perovskite solar cells. Because they are very thin, these cells are highly flexible and transparent.59,62,72,73,75-78
III‐V compound Cells based on these compounds, such as GaAs, InP (indium phosphide), and GaSb (gallium antimonide), have direct energy bandgaps, exhibit
by the chemical and structural instability of the perov-skite materials are still cause for concern and need to be studied; ie, to develop a photovoltaic solar cell of perov-skite without lead and with high efficiency is still seen as a challenge for researchers, although they are optimis-tic. Further advances can be achieved by combining perovskite cells with silicon or CIGS (perovskite‐based tandem solar cells).83-88
Studies point out that solar cells of organic and inor-ganic hybrid halogens perovskite are feasible if compara-ble with other photovoltaic methods, due to the abundance of this material in the earth, almost perfect crystallinity at low temperature, low cost, and easy to fab-rication. In this way, they may be a potential competitor for crystalline silicon solar cells.88-90
The second stage consisted of the identification of the specialists, the elaboration of the research questionnaire, the application planning, the operation of the Delphi technique, and feedback. The third stage contemplated the analysis and structuring of results.
4 | T E C H N O L O G I C A L
P R O S P E C T I N G O F P H O T O V O L T A I C
C E L L S W I T H E M P H A S I S O N T H E I R
T E C H N I C A L
‐COMMERCIAL
V I A B I L I T Y
This topic presents the application description of the Del-phi technique performed in the year 2015 in the techno-logical prospection of photovoltaic cells for solar energy. The current and future map (for the years 2020 and 2025) of photovoltaic cell technologies, which have been identified through article and patent analysis, is also based on technical and commercial viability.
The application of the Delphi technique occurred as described in Figure 2.
The development of the Delphi query was performed in seven steps, which are detailed in subsection 4.1. The stages included selection of specialists; invitation by e‐ mail; submission of the first round questionnaire, statisti-cal analysis of data from the first round; feedback and submission of the second round questionnaire; and
statistical analysis of the second round and consider-ations. The latter is the development of this topic.
4.1 | Description of the Delphi technique
application
As shown in Figure 2, initially, the selection and contact with academics/researchers and companies of various nationalities, acting in the photovoltaic technology area, was made. Thirty experts were contacted via e‐mail/ telephone to find out if they were interested and willing to participate in the research. Only 18 experts answered the email/answered the calls and mentioned interest and availability to participate in the survey. Accordingly, a formal invitation and acceptance form were sent via e‐mail to the 18 specialists, 12 of whom were academics/researchers and six business representa-tives. However, for reasons unknown to us, only the Bra-zilian specialists (eleven) answered the e‐mail returning the agreement to participate in the survey. Of these 11 TABLE 2 (Continued)
Technology Description
high optical absorption coefficients, high production cost, better resistance to irradiation, and better weight/power ratio in space applications. These solar cells were initially developed to power satellites in space and are now beginning to explore the market for terrestrial energy through the use of photovoltaic energy concentrator systems.55,79-82
Source: Compiled from authors referenced in the table.
Brazilian guests, five were members of companies and six academics.
RBS allowed us to identify researchers on photovoltaic technologies and some companies that manufacture pho-tovoltaic modules. Regarding the specialists who work in companies, those who are part of the technical depart-ment were selected. Experts have been found to be inde-pendent. Table 3 gives a brief description of the experts who agreed to participate in the survey.
The specialists 3, 5, 7, 9, and 11 work in companies, and the others are teachers of Federal Teaching Universities.
The process of obtaining expert opinions was carried out through a structured questionnaire sent by e‐mail. The questionnaire used in the expert consultation was composed of four objective questions for each of the nine technologies put under trial and a subjective question, besides including a field for justifications and comments.
The first question to be answered in the first round questionnaire was about the respondent's level of knowl-edge about each of the nine technologies in question, whose response options were as follows:
• Expert: if you are dedicating yourself to the subject and know it in depth.
• Connoisseurs:
a. If you are becoming an expert, but you feel that you lack some experience to master the topic;
b. If you have been an expert on the topic for some time, but you are not currently updated.
• Familiarized: most aspects related to the topic are known, but have not worked and do not work in the topic area, or if you work in the next or related area. • Unfamiliar: if you know some of the aspects related to
the topic or read about it or have any opinion about it. This self‐assessment of the respondents allowed the responses to be separated according to the level of exper-tise of the respondent, allowing for analysis in the inves-tigation of their influence during the Delphi consultation. The second issue was about the technical‐commercial viability of each technology today. If the respondents felt that the technology is not viable these days, they should answer the next question that asked whether the technol-ogy could become technically feasible in 2020. Some experts, even thinking that a particular technology is not viable these days, have stopped responding to the viability of such technology in 2020. If the respondent thought that the technology was not viable in 2020, they should answer TABLE 3 Delphi technique application synthesis
Expert Level of education Company/educational institution
1 Doctorate: Photovoltaic conversion of solar energy by the higher technical School of Ingenieros de Telecomunicación—Universidad Politécnica de Madrid
Federal University of Rio Grande do Sul (UFRGS)
2 Doctorate in engineering from the Polytechnic University of Madrid
Pontifical Catholic University of Rio Grande do Sul (PUCRS)
3 Master's degree in electrical engineering from UFRJ Research and Development Center Leopoldo Américo Miguez de Mello—CENPES/PETROBRÁS
4 Doctorate in Materials from Penn State University Federal University of Minas Gerais (UFMG) 5 Master's degree: Electrical engineering, Federal
University of Pernambuco.
Research and Development Center Leopoldo Américo Miguez de Mello—CENPES/PETROBRÁS
6 Doctorate in electrical, electronics, photonics and systems engineering from Université Paul Cézanne —Aix‐Marseille
Federal University of Paraíba (UFPB)
7 Graduate in production engineering and bioenergetics
Minasol photovoltaic panels 8 Doctorate in engineering from the Polytechnic
University of Madrid
Pontifical Catholic University of Rio Grande do Sul (PUCRS)
9 Project specialist—Energy coordination Brazilian Agency for Industrial Development (ABDI) 10 Doctorate in electrical engineering from the Federal
University of Paraíba
Federal University of Rio Grande do Norte (UFRN) 11 Graduate in mechanical engineering from the
Federal University of Ceará
Gas technologies and renewable energy center (CTGAS‐ER)
the third question that asked whether the technology could become technically and commercially viable in 2025.
Of the 11 questionnaires sent, eight were answered. The three specialists (experts 9, 10, and 11 from Table 3) who did not respond to the questionnaire and who had initially confirmed their participation reported that they were no longer able to participate in the study for reasons beyond their control. After the questionnaire was applied, the statistical analysis and tabulation of the answers were done by means of the percentage calculation of the answers, yes, no, and maybe, to verify the consensus among the specialists. The integer analysis was performed with the help of Microsoft Excel software.
Normalization of expert opinion was made by calculat-ing the percentage of responses:
• For monocrystalline and multicrystalline silicon cells, there were eight respondents. Thus, the response of each specialist to monocrystalline and multicrystalline silicon cells corresponded to 12.5% (1/8).
• For the remaining cells, there were seven respondents, as specialist number 7 chose to abstain, remain neu-tral, and not answer about other technologies because they considered themselves unfamiliar with them. Thus, the response of each specialist to the other cells corresponded to 14.28% (1/7).
It was established that the quiz round process would end when stability or consensus response levels were reached. As there are no well‐defined rules for the estab-lishment of these criteria in the literature, it was decided to consider that when 2/3 of respondents had the same opinion, convergence would be established. Stability was considered achieved when minus 2/3 did not change their responses between rounds.
In the analysis of the first round, the answers were divided into two groups. The first group was the one with more specialized respondents, made up of those who answered in the first question that they were “experts” and“connoisseurs” in the technological topic in question. The second group was formed by the “familiar” and “unfamiliar.” The division into groups aimed to investi-gate if the responses of the less specialized group would converge towards the more specialized group when apply-ing the first to the second round.
Already in the first round, there was a consensus among the participants, regardless of their specialty, in relation to the current scenario of all the technologies analyzed, but the same did not happen in relation to the scenarios of 2020 and 2025. It could be noticed that for the questions that presented divergence of opinions, it occurred within the same group; that is, in the more spe-cialized group, some experts pointed out to have a
different understanding of the other participants of this group. In order to resolve doubts that emerged during the application of the first round and to seek the consen-sus of the issues that presented divergence, the question-naire was restructured, reopening the issues, whose opinions were controversial.
With this, the second round was started, which besides the restructured questionnaire, the feedback was included with the guarantee of the anonymity of the respondents. In this way, the specialist could either keep his response or change it due to a new reading or reflection on the issue. The questionnaire also included a field for the spe-cialist to justify and/or comment on his/her response if he/she felt it necessary.
Of the eight questionnaires sent in the second round, all were answered. After receiving the questionnaires, to check whether there was an increase or not of the consen-sus among the experts on the issues that presented diver-gence of opinions, the statistical tabulation and analysis of the answers were done by comparing the percentage value of the answers of the second round in relation to the former.
There was no divergence from the first to the second round between the responses from the least specialized group to the most specialized group. That is, although they considered themselves only“unfamiliar” and “unfa-miliar,” the respondents in this group, both in the first and second rounds, indicated that they had the same viewpoint as most “experts” and “connoisseurs” regard-ing to the issues addressed.
It was verified, within the most specialized group, that there was a convergence of opinions and consequently the consensus for the technologies (monocrystalline and polycrystalline silicon cells; silicon nanowires; indium/copper selenide, indium, and gallium diselenide; multijunction—compounds III‐V; and carbon nanostruc-ture [graphene, carbon nanotube, and fullerene]) in which consensus was not obtained in the first round.
For amorphous silicon, cadmium telluride cells, organic photovoltaic cells, and dye‐sensitized cells, the stability criterion prevailed, since even without reaching the intended consensus in the second round, the experts did not change their opinion regarding the technical‐ commercial viability of these technologies.
4.2 | Analysis of responses at the end of
the Delphi technique
This topic deals with the analysis of the answers, regard-ing the questions about the technical‐commercial viabil-ity for the year 2015 and within the horizon of 5 (2020) and 10 years (2025) for the nine photovoltaic technologies
identified through the analysis of articles and patents. The experts had the following response options: Yes, technol-ogy is feasible; no, technoltechnol-ogy is not feasible; maybe, maybe the technology is viable.
The technical‐commercial feasibility, questioned in this research, depends on the use of these technologies, that is, whether it will be used in isolated generation, plants, minigeneration, and distributed microgeneration, since these cases are completely different from the com-mercial point of view, even though they use essentially the same equipment.
Figures 3–5 summarize the responses obtained with the Delphi query for 2015, 2020, and 2015, respectively. In order to maintain the anonymity of the experts, they were numbered from 1 to 8. The expert number 7 only answered the questions regarding monocrystalline and multicrystalline silicon cells, that is, chose to abstain, to remain neutral, and not to respond on the other technol-ogies because he/she considered to be unfamiliar with them.
For the monocrystalline silicon cell, 100% of the respondents answered that this technology is technically viable nowadays and will continue to be in 2020. In the opinion of the experts, corroborating with the research of other studies,54-60 this is one of the technologies that dominates the current market, is mature, the raw mate-rial used in its manufacture is abundant, has high conver-sion efficiency, great penetration power in the current market, and numerous manufacturers worldwide. How-ever, it requires energy‐intensive and costly productive processes, and therefore, 12.5% believe that it will not continue to be technically and commercially viable in 2025. Those who believe that this technology will con-tinue to be viable in 2020 justify the view, given that in such a short time, a radical change is unlikely to make this technology disappear and that it is solid, consistent, and constantly evolving. There may even be other tech-nologies, but this will continue in the market due to a maintenance of production caused by the spread of tech-nology around the world, which will cause other coun-tries to start producing it leading to a reduction in the cost of the final product.
As well as for the monocrystalline silicon cell, the expert opinion was unanimous regarding the multicrystalline silicon cell of the same to be commer-cially viable today and will continue to be in 2020. The reasons given for this view are that this technology is commercially mature and that dominates the current market, abundant raw material, high conversion effi-ciency, greater penetration power in the current market, and many manufacturers around the world. However, although less restrictive, because it is more simplified than monocrystalline, it requires energy‐intensive and costly productive processes, and therefore, 12.5% do not believe that this technology will continue to be viable in 2025. The reasons why those who believe that this tech-nology will continue to be viable are the same as those presented for monocrystalline silicon cells.
The experts' view of today's crystalline silicon cells cor-roborates with the reports of the previous studies,91,92 which state that crystalline silicon dominates the current market for photovoltaic solar energy, occupying a parcel of about 90%. However, it is believed that the potential for cost reduction and the potential for increased effi-ciency are limited, a fact that justifies the opinion of 12.5% of the experts, who believe that perhaps by 2025, these cells are not technically feasible.
The opinion that monocrystalline/multicrystalline sili-con cells will not be viable in 2025 is from a self‐rated respondent as being expert or expert on monocrystalline and multicrystalline silicon cells. In his opinion, “Mono/multicrystalline silicon technology is not suitable for large scale production. The process automation you FIGURE 4 Summary of the application of the Delphi technique
for 2020 [Colour figure can be viewed at wileyonlinelibrary.com]
FIGURE 5 Summary of the application of the Delphi technique for 2025 [Colour figure can be viewed at wileyonlinelibrary.com] FIGURE 3 Summary of the application of the Delphi technique for 2015 [Colour figure can be viewed at wileyonlinelibrary.com]
see today only remedies this. In ten years it is possible for the market to grow so much that simpler‐made modules will eventually prevail.”
In the opinion of all the experts consulted, the silicon nanowire cell is not considered technically feasible nowa-days. One reason is that the cost/efficiency ratio is very high. It is a technology still under research and without much room for increased efficiency. What is more, any technology that is present today in the laboratories finds a serious barrier to entry: How to overcome, starting small, the low price of the gigantic Asian industry of crys-talline silicon modules? From the point of view of the interviewees, the only way to do this is to guarantee a very low cost of production coupled with high efficiency. Nanowire technology does not yet offer this guarantee; 71.4% of experts think it will still not be viable in 2020. In order for there to be a technical‐commercial viability perspective for 2020, models capable of being produced on a large scale or technological maturation should be presented, which would prove their applicability. In 2025, for 71.4% of respondents, this technology may be viable, but this will depend largely on the evolution of the research and development results of such technology. The cost/benefit ratio would have to be improved and specific market niches to be found.
Amorphous silicon cells, for 100% of specialists, are considered technically and commercially viable today for certain niche markets such as applications where flexible modules are required or in very hot climates with high irradiance diffuse. This technology operates in a restricted market due to its technological character-istics (mainly low conversion efficiency). By 2020, fewer respondents (71.4%) believe that this technology will remain viable. Experts who believe that this technology will not continue to be viable in 2020 follow the latest data released by Fraunhofer Institute93 on the market share of thin film technologies, which show the technology's share declining over the years. But in 2025, to 57.1% of experts, it may not be feasible because it is doomed to disappear or continue to work only in restricted applications. It turns out that amorphous sili-con technology has been on the market for a long time and has failed to raise efficiency in order to make it competitive. What has not been achieved to date, even with so much effort, is unlikely to be achieved unless one finds a way to improve conversion efficiency that rivals the other, more usual, and emerging thin film technologies.
Cadmium telluride cells, for 100% of respondents, pres-ent technical‐commercial viability today, because it is a technology with extremely low production cost, uses less material than crystalline silicon because it is thin film, with final costs, of module, comparable. For the year
2020, 71.4% of respondents believe that this technology will still remain technically‐commercially viable. The decrease in the number of experts who believe that this technology will continue to be viable in 2020 corroborates the declining trend of this technology's share over the years, which is presented in the latest data released by Fraunhofer Institute93about the market share of thin film technologies. However, in the opinion of the experts, cor-roborating with previous works,56,62,64-66,94the evolution of this technology is limited by the availability of tellu-rium, which is rare, by the toxic aspect of cadmium and being manufactured by a single major manufacturer (First Solar [USA]). This fact leads the experts (57.1%) to believe that this technology may not be more viable in 2025.
In the opinion of all respondents, indium/copper, indium, and gallium diselenide selenide cells are consid-ered technically and commercially viable today. To 85.7% of respondents Indium copper selenide/Copper, indium and gallium‐diselenide cells will remain techni-cally and commercially viable until 2020. One reason is low production cost, as it uses less material than crystal-line silicon because it is thin film. From the latest data released on Fraunhofer Institute93 market share of thin film technologies, it is not possible to observe a pattern in the trend of this technology's share over the years, since there were years when this technology grew its par-ticipation and years that parpar-ticipation has decreased. Thus, for the year 2020, it may be that the expert opinion is confirmed. However, there are currently a few indus-tries producing photovoltaic modules with this technol-ogy, and their evolution is limited by the availability of the Indian and gallium elements that are rare and by the toxic aspect of the cadmium used in the cell buffer layer. This leads 71.4% of experts to believe that this tech-nology may no longer be feasible by 2025. This fact may be reversed as long as this technology continues its path of increasing efficiency with a reduction in production costs.
The understanding of the experts who believe that in 2020 and in 2025, the amorphous silicon; cadmium tellu-ride; and indium copper/copper, indium, and gallium‐ diselenete cells will not be as viable technically‐ commercially corroborates with the report of Research and Markets,92 which states that the relatively low effi-ciency of amorphous silicon cells (about 12% in module size) will result in their limited large‐scale applications, and that in the long term such as difficulty in acquiring tellurium and toxicity of cadmium, market growth for CdTe based photovoltaic modules likely to stabilize and that the market for CIS/CIGS technologies will also be limited despite the relatively higher growth rate com-pared with CdTe technology.
ITRPV95predicts a positive growth in market share for CIGS and other thin films until 2025. There is a big differ-ence between expert opinion and ITRPV, as experts con-sidered that when the research was done (2014), there were few industries producing photovoltaic modules with this technology and its evolution was limited by the avail-ability of rare indium and gallium elements and the toxic aspect of cadmium used in the cell buffer layer. However, experts considered that this fact could be reversed as long as this technology continued its trajectory of increasing efficiency with reducing the cost of production.
For most of the experts consulted (85.7%), organic cells do not have technical‐commercial viability these days, because despite the potential low cost, they have low effi-ciency and a restricted market. In addition, the specialists, corroborating with the previous works,59,68,72,73 report that this technology presents problems of durability (deg-radation) and are still in the research phase; 57.1% believe that this technology is likely to be commercially viable in 2020 and 2025, since, although restricted, it will have its niche market guaranteed, especially for applications where its flexibility feature is utilized to equip surfaces that need a certain curvature, bending, twisting, etc, with low cost and low electrical power.
Among the various materials that can be used in the manufacture of organic cells, the specialists have been specifically consulted about cells based on carbon nano-structure, such as graphene, carbon nanotube, and fuller-ene. Organic cells based on carbon nanostructure were specifically consulted because they were identified in the analysis of the Systematic Bibliographic Review as a promising technology whose studies are growing.
From the point of view of experts, carbon nanostruc-tures are not technically‐commercially viable today (100% think so) and will continue not be in 2020 (100% think so). Maybe in 2025, for 85.7% of specialists, the car-bon nanostructures will be technically and commercially viable. According to experts, the organic cells based on carbon nanostructure are still in the research and devel-opment stage, have a low conversion efficiency, and may be doomed to the complementary character, in search of efficiency improvements, in order to add value to the technologies already existing. The promises of a sig-nificant increase in efficiency are quite encouraging, but the cost of the materials involved, coupled with some technological barriers of difficult transposition, leads to a rather skeptical position on this technology. By 2025, the expectation, according to the opinion of 85.7% of experts, is that this technology may be commercially via-ble. It will depend quite a bit on the evolution of the research and development result of such technology in a way that justifies its use, perhaps hybrid or combined with other technology. A fact that negatively influences
the technical and commercial feasibility of this technol-ogy in 2025, besides its technological immaturity, is the market penetration of other technologies, especially thin film (CdTe and CIGS).
Like organic cells, the dye‐sensitized cells have low conversion efficiency and restricted market (as a decora-tive function equipping architectural surfaces, facades, and stained glass to generate electricity) and are therefore not considered viable today (85.7% of specialists they think so). With the opinion of 71.4% of experts, this fact will be perpetuated until 2020, since despite the potential low cost, it presents serious problems of durability and efficiency, with no potential for increase. However, for 57.1% of specialists, depending on the evolution of the technology, it may well become feasible in 2025 for appli-cations where cost is more important than efficiency.
Corroborating with expert opinion, the reports91,92 affirm that organic cells and dye‐sensitized solar cells and perovskite solar cells are now being developed but are still not technically‐commercially viable. However, they are great promise for the future, but for conventional applications, they need to achieve specific performance and cost levels to enter the market.
Regarding multijunction cells (compounds III‐V), 71.4% of the respondents agreed that this technology is technically and commercially viable today and will remain in 2020 (71.4% of respondents) and in 2025 (85.7% of respondents). Among the justifications given by the specialists is that the technology in question is marketed in niche markets for which price is not so important. It is considered viable for restricted applica-tions (regions with high degree of direct irradiation and very little cloudiness, solar concentrators, and space applications) on a small scale. It features high conversion efficiency, small dimensions, and high electrical power available. However, it is a technology that is difficult to fabricate because of the many layers that make up each cell junction and difficult to control the spectral response of the junction set. The reasons why experts believe that multijunction cells will remain commercially viable by 2020 and between 2020 and 2025 is that despite being restricted because of the high cost of production, the mar-ket for this technology will continue to exist. The high cost of production, noted by experts, is also seen by liter-ature55,80,81 as a challenge to be overcome. The lack of raw materials should also be taken into account. Although it is an expensive technology for terrestrial use, it can be competitive in plants in desert sites as long as the cost of production falls accordingly.
Researchs on reducing the cost of multijunction cells (compounds III‐V) support the opinion of experts as to the technical‐commercial viability of these cells. Studies such as Zafar and Iqbal96 on the application of indium
phosphide (InP) in photovoltaic solar cells point out that it is possible to obtain high efficiency and low‐cost InP solar cells. The search results of Ghahfarokhi97 indicate the prospect of GaAs nanowire solar cells to provide higher output power and consequently cheaper electricity generation. These cells are promising candidates for future applications because of their advantageous proper-ties, such as improved light capture and reduced material.
4.3 | Current and future map of the
technical
‐commercial viability of
photovoltaic cell technologies
In this stage, the current and future map of the technical‐ commercial viability of photovoltaic cell technologies is presented as a result of the experts' opinion. Figure 6 illustrates the technical‐commercial viability of today's technologies as well as prospecting for each of the tech-nologies in the time horizon of 5 and 10 years.
The current map shows the monocrystalline, multicrystalline, and amorphous silicon cells; cadmium telluride; copper/indium copper selenide, indium, and gallium diselenide; and multijunction (III‐V compounds) as being technically and commercially viable today and cells of silicon nanowires, organic, dye sensitized, and those based on carbon nanostructure (graphene, carbon nanotube, and fullerene) as not viable.
For the year 2020, the future map shows that mono-crystalline, multimono-crystalline, and amorphous silicon cells; cadmium telluride; indium copper selenide/copper, indium, and gallium diselenet; and multijunction (III‐V compounds) will still have technical‐commercial viability and that dye‐sensitized silicon nanowire cells and those based on carbon nanostructure will continue to be nonvi-able. The change that may occur from the present day to the year 2020 is that perhaps the organic photovoltaic cells will become viable.
The future map for the year 2025 presents as still viable the monocrystalline and multicrystalline silicon cells and the multijunction cells—compounds III‐V, as well as that perhaps the dye‐sensitized silicon nanowire cells and those based on nanostructure of become viable. In addi-tion, the map also shows that amorphous silicon; cad-mium telluride; and indium copper/copper, indium, and gallium‐diselenete cells may still remain viable and that organic photovoltaic cells may be viable.
This scenario outlined for 2020 and 2025 could be modified as the evolution of existing technologies and the emergence of new ones.
5 | C O N C L U S I O N
Identifying emerging technologies and their technical‐ commercial viability is of fundamental importance both for companies and for society in general. With this, it FIGURE 6 Current and future map of photovoltaic technologies
becomes possible for a company, for example, to align its efforts in order to achieve its strategic objectives. In this way, technology management requires effective processes to ensure that existing and potential technological resources are in line with the needs, now and in the future of an organization.
To that end, there are some prospecting techniques that may depend on the situation (specificities in the area of knowledge, application of technologies in the regional or local context, governmental or business, scope of the exercise, time horizon, cost, objectives, and underlying conditions). To that end, there are some prospecting tech-niques that depending on the situation (specificities in the area of knowledge, application of technologies in the regional or local context, governmental or business, scope of the exercise, time horizon, cost, objectives, and under-lying conditions), can be used separate or jointly, which is very common to complement the different characteristics of each one, seeking to compensate for the possible defi-ciencies brought about by the use of isolated techniques. Regarding the opinion of the experts, one of the most used techniques is Delphi.
The mapping of photovoltaic technologies through article and patent analysis identified monocrystalline and multicrystalline silicon cells; silicon nanowires; amorphous silicon; cadmium telluride; indium copper/copper, indium, and gallium‐diselenete selenium; organic photovoltaic cells; dye‐sensitized; multijunction (III‐V compounds); and cells based on carbon nanostruc-ture (graphene, carbon nanotube, and fullerene), which served as a basis for technological prospecting through the application of the Delphi technique.
The operation of the Delphi technique took place in two rounds, once a consensus was obtained between the participants. It was noticed that for this to happen, the first question of the expert's self‐assessment questionnaire on a particular technology was fundamental.
The survey results indicate that for 100% of experts, monocrystalline and multicrystalline silicon cells will continue to be technically‐commercially viable by 2020, while organic cells based on carbon nanostructures will not yet be. However, for the 2025 scenario, for 85.7% of experts, carbon nanostructure cells, depending on technological advances and incentives, could become commercially viable.
Thus, the application of the Delphi technique was rel-evant in the identification of technologies that are technically‐commercially viable today and that will be in the future (2020 and 2025), since the opinion of the experts corroborated with the information disclosed in the reports IEA (2014) and Research and Markets (2017). The Delphi technique applied in this study presented some advantages such as, for example, participants being
able to present their ideas at different times and places without having to gather all in a single environment allowed individual reflection (first round) and collective reflection (second round) on the future of photovoltaic technologies and added knowledge to the process. About limitations of the Delphi technique in this research are that, of the 18 specialists of different nationalities who were contacted, only 11 Brazilians accepted to participate in the Delphi technique; however, only eight answered the questionnaires of the first and second rounds. In view of this fact, it is suggested that in future studies, the appli-cation of the technique be with a greater number of spe-cialists to verify the results of this research.
A C K N O W L E D G E M E N T
We acknowledged Mrs Theresa O'Brien de Brito for the English language review.
F U N D I N G I N F O R M A T I O N
This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES)—Finance Code 001.
O R C I D
Priscila Gonçalves Vasconcelos Sampaio https://orcid.org/ 0000-0003-0820-3817
R E F E R E N C E S
1. Wang Z, Porter AL, Wang X, Carley S. An approach to identify emergent topics of technological convergence: a case study for 3D printing. Technological Forecasting & Social Change. 2019;146:723‐732.
2. Porter A et al. Technology futures analysis: toward integration of the field and new methods. Technological Forecasting & Social
Change. 2004;71(3):287‐303.
3. Li X, Zhou Y, Xue L, Huang L. Integrating bibliometrics and roadmapping methods: a case of dye‐sensitized solar cell technology‐based industry in China. Technological Forecasting
& Social Change. 2015;97:205‐222.
4. Chen H, Ma T. Technology adoption with limited foresight and uncertain technological learning. European Journal of
Operational Research. 2014;239(1):266‐275.
5. Picatoste J, Pérez‐Ortiz L, Ruesga‐Benito SM. A new educational pattern in response to new technologies and sustainable development. Enlightening ICT skills for youth employability in the European Union. Telematics and Informatics. 2018;35(4): 1031‐1038.
6. Carvalho MM, Fleury A, Lopes AP. An overview of the literature on technology roadmapping (TRM): contributions and trends.
7. Dong A, Sarkar S. Forecasting technological progress potential based on the complexity of product knowledge. Technological
Forecasting & Social Change. 2015;90:599‐610.
8. Ciobanu OG, Neamţu DM. The impact and importance of new technologies in business development in context of economic diversity. Proceedings of the International Conference on Business
Excellence. 2017;11(1):698‐710.
9. Phaal R, Farrukh CJP, Probert DR. Technology roadmapping: a planning framework for evolution and revolution. Technological
Forecasting & Social Change. 2004;71(1‐2):5‐26.
10. Coelho GM, Santos DM, Santos MM, Fellows FL. Caminhos Para o desenvolvimento em prospecção tecnológica: technology Roadmapping um olhar sobre formatos e processos. Parcerias
Estratégicas, Brasília. 2005;21:199‐234.
11. Howell R, Van Beers C, Doorn N. Value capture and value creation: the role of information technology in business models for frugal innovations in Africa. Technological Forecasting &
Social Change. 2018;131:227‐239.
12. Shanmugam K, Zainal NK, Gnanasekaren C. Technology foresight in the virtual learning environment in Malaysia.
Journal of Physics: Conference Series. 2019;1228:012068. 13. Park I, Yoon B. Technological opportunity discovery for
technological convergence based on the prediction of technology knowledge flow in a citation network. J Informet. 2018;12(4): 1199‐1222.
14. Santos M et al. Prospecção de tecnologias de futuro: métodos, técnicas e abordagens. Parcerias Estratégicas. 2004;19:189‐229. 15. Makarova EA, Sokolova A. Foresight evaluation: lessons from
project management. Foresight. 2014;16(1):75‐91.
16. Boe‐Lillegraven S, Monterde S. Exploring the cognitive value of technology foresight: the case of the Cisco Technology radar.
Technological Forecasting & Social Change. 2015;101:62‐82. 17. Proskuryakova L. Energy technology foresight in emerging
economies. Technological Forecasting & Social Change. 2017;119:205‐210.
18. Featherston CR, O'sullivan E. Enabling technologies, lifecycle transitions, and industrial systems in technology foresight: insights from advanced materials FTA. Technological Forecasting & Social
Change. 2017;115:261‐277.
19. Kupfer D, Tigre PB. Prospecção tecnológica. In: Caruso, L. A.;
Tigre, P. B. (Org.). Modelo SENAI de prospecção: documento metodológico. OIT/CINTERFOR: Montevideo; 2004.
20. Mayerhoff ZDVL. Uma análise sobre os estudos de prospecção
tecnológica. Rio de Janeiro: Instituto Nacional da Propriedade Industrial; 2008.
21. Teixeira LP. Prospecção Tecnológica: importância, métodos e
experiências da Embrapa Cerrados. Planaltina, DF: Embrapa Cerrados; 2013:1‐34.
22. Zhang Y, Porter A, Chiavetta D, Newman NC, Guo Y. Forecasting technical emergence: an introduction. Technological
Forecasting & Social Change. 2019;146:626‐627.
23. Huang Y, Porter AL, Zhang Y, Lian X, Guo Y. An assessment of technology forecasting: revisiting earlier analyses on dyesensitized solar cells (DSSCs). Technological Forecasting &
Social Change. 2019;146:831‐843.
24. Barre R. Innovation systems dynamics and the positioning of Europe. A review and critique of recent foresight studies.
Foresight. 2014;16(2):126‐141.
25. Fernández‐Güell JM, Collado M. Foresight in designing sun‐beach destinations. Tour Manag. 2014;41:83‐95.
26. Haleem A, Mannan B, Luthra S, Kumar S, Khurana S. Technology forecasting (TF) and technology assessment (TA) methodologies: a conceptual review. BIJ. 2019;26(1):48‐72.
27. Esmaelian M, Tavana M, di Caprio D, Ansari R. A multiple correspondence analysis model for evaluating technology foresight methods. Technological Forecasting & Social Change. 2017;125:188‐205.
28. Coates V, Farooque M, Klavans R, et al. On the future of technological foresight. Technological Forecasting & Social
Change, New York. 2001;67(1):1‐17.
29. Linstone HA, Turoff M. Delphi: a brief look backward and forward.
Technological Forecasting & Social Change. 2011;78(9):1712‐1719. 30. Zio SD, Pacinelli A. Opinion convergence in location: a spatial
version of the Delphi method. Technological Forecasting & Social
Change. 2011;78(9):1565‐1578.
31. Von Der Gracht HA. Consensus measurement in Delphi studies review and implications for future quality assurance. Technological
Forecasting & Social Change. 2012;79(8):1525‐1536.
32. Förster B, Von Der Gracht HA. Assessing Delphi panel composition for strategic foresight—a comparison of panels based on company‐internal and external participants.
Technological Forecasting & Social Change. 2014;84:215‐229. 33. Myllylä Y, Kaivo‐Oja J. Integrating Delphi methodology to some
classical concepts of the Boston consulting group framework: arctic maritime technology BCG Delphi foresight‐a pilot study from Finland. Eur J Futures Res. 2015;3(1):2.
34. Mik SML et al. Delphi study to reach international consensus among vascular surgeons on major arterial vascular surgical complications. World J Surg. 2019;43(9):2328‐2336.
35. Oliveira JSP, Costa MM, Wille MFC. Introdução ao Método
Delphi. Frist ed. Curitiba: Mundo Material; 2008.
36. Li N, Chen K, Kou M. Technology foresight in China: academic studies, governmental practices and policy applications.
Technological Forecasting & Social Change. 2017;119:246‐255. 37. Linstone HA, Turoff M. The Delphi method: techniques and
applications. London: Addison‐Wesley; 1975.
38. Cardoso LRA et al. Prospecção de futuro e Método Delphi: uma aplicação Para a cadeia produtiva da construção habitacional.
Ambiente Construído. 2005;5:63‐78.
39. Ecken P, Gnatzy T, Von Der Gracht HA. Desirability bias in foresight: consequences for decision quality based on Delphi results.
Technological Forecasting & Social Change. 2011;78(9):1654‐1670. 40. Landeta J, Barrutia J, Lertxundi A. Hybrid Delphi: a methodology
to facilitate contribution from experts in professional contexts.
Technological Forecasting & Social Change. 2011;78(9):1629‐1641. 41. Alcon F, Tapsuwan S, Martínez‐Paz JM, Brouwer R, de Miguel
MD. Forecasting deficit irrigation adoption using a mixed stakeholder assessment methodology. Technological Forecasting
