1. Introduction
In response to the global warming issue, major countries around the world have focused on the development of green energy with clean, low-temperature greenhouse gas emissions and self-sufficient characteristics as one of the key considerations in future energy policies [
1,
2]. Taiwan is also actively promoting the emerging 3E green energy industry, green production equipment, and technological projects that emphasize energy saving, environmental protection, and economic development. These initiatives not only drive industrial transformation but also create increased demand for talent and job opportunities in the market, positioning workers in the green energy industry as in-demand green-collar professionals. Among all renewable energy sources, in addition to large-scale hydropower, wind power and solar photovoltaic have received significant global attention. Among these, wind power is one of the most mature and commercially viable renewable energy technologies with promising prospects for commercial development [
3]. According to the “Global Offshore Wind Speeds Rankings“ by 4C Offshore, the Taiwan Strait is a prime region for resources worldwide. Among the top 20 offshore wind sites with the most favorable wind conditions, the Taiwan Strait accounts for 16 of them [
4]. Furthermore, the National Aeronautics and Space Administration (NASA) indicates that the coastal region of Changhua consistently experiences wind speeds exceeding 7 m/s throughout the year, with an average wind power density surpassing 750 W/m
2. This unique and advantageous environment has led to the development of the largest-scale offshore wind farms within this region in Taiwan [
5]. Various studies have consistently demonstrated the excellent wind energy resources in Taiwan, particularly in offshore wind power generation, which exhibits significant development prospects and potential. Consequently, the government has been continuously revising and expanding its renewable energy goals over the years. In 2010, a target of 10,858 MW was announced, followed by a revision in 2011 to increase the target to 12,502 MW. In 2014, the target was further elevated to 13,750 MW, and in 2015, a substantial revision was made to the new energy policy goal, aiming to raise the proportion of renewable energy generation to 20% by 2025 [
6]. The detailed contents of the plan are presented in
Table 1.
Under the policies and trends of the green energy industry, certain issues arise in terms of infrastructure, localization of the industry chain, and the demand for green manpower. The “4-Year Offshore Wind Power Promotion Plan” produced by Taiwan’s Bureau of Energy, Ministry of Economic Affairs, implements a policy of “demonstration first, potential second, and block development later”, as well as a policy of “shallow waters first, deep waters later” for offshore wind power installation. Due to favorable policy factors, numerous Taiwanese companies have entered the offshore wind power industry, producing components for offshore wind turbines. In the construction of offshore wind farms, apart from the core offshore wind turbine, the most crucial aspect is the sturdy construction of the turbine tower and underwater foundation to withstand Taiwan’s natural disasters and environmental threats. The construction of underwater foundations is an essential part of the localization of the wind power industry in Taiwan [
6].
According to the preliminary requirements of the “Industrial Development Plan” produced by the Bureau of Industrial Development, Ministry of Economic Affairs, offshore wind farm developers are required to commit to using underwater foundations manufactured by domestic companies. This has attracted various companies to enter this field, and the demand for welding professionals has also increased to enhance the capacity to produce underwater foundations [
7]. Taking into account safety, economic value, and referencing the development trends in offshore wind power in Europe and America, most domestic wind farm developers prefer to use monopile foundations and jacket foundations as their main products. Monopile foundations are chosen due to their simple structure, low manufacturing costs enabled by automated welding equipment, and sufficient structural strength and support capabilities. They are suitable for the hard seabed soil on the northwest coast north of Miaoli. On the other hand, jacket foundations have a more complex overall structure and often require manual welding techniques, making them more expensive to produce. However, they possess relatively stronger structural strength and can withstand Taiwan’s harsh weather conditions. They are suitable for the soft seabed soil on the southwest coast south of Miaoli [
8].
The construction techniques for offshore wind power projects are not only challenging but also require specialized expertise. As Taiwan is still in the early stages of offshore wind power development, many underwater foundation welding techniques need to be learned from Europe. Based on the experience of several European underwater foundation manufacturers, the fabrication of underwater foundations mainly involves the assembly of steel structures, with a significant demand for skilled welding personnel. Each production line requires at least 200 professional welders, and during peak periods, may accommodate up to 600 welders working simultaneously [
9].
Therefore, the demand for welding professionals is also a challenge that domestic manufacturers face when entering the production process. For offshore wind power developers in Europe, apart from manufacturing capabilities, one of the most important aspects is having engineering expertise that meets international certifications. Not only must welding personnel qualifications meet the requirements of ISO 9606-1:2012 [
10], but compliance with EN 1090-1: 2009 + A1:2011, EN 1090-2:2018, EN 1090-3:2008, EN 1090-4:2018, EN 1090-5:2017 (EU structural steel certification) [
11,
12,
13,
14,
15] and ISO 3834-1:2021, ISO 3834-2:2021, ISO 3834-3:2021, ISO 3834-4:2021 (welding quality management system certification) [
16,
17,
18,
19] has also become one of the qualification requirements for manufacturing companies. This serves to demonstrate that their welding engineering management adheres to international standards [
20].
Welding is an indispensable foundational technique in industry, with applications in various large structures such as steel buildings, bridges, boilers, storage tanks, chemical equipment, machinery, vehicles, ships, aircraft, offshore wind power substructures, and towers. Its application scope is extensive. In the construction of offshore wind power substructures, the selection of steel materials must meet the stringent weather conditions in Taiwan. High-strength steel plates certified by DNV-GL (Det Norske Veritas-Germanischer Lloyd) specifications, such as S355ML, S420ML, S460ML, S555ML, are chosen for this purpose [
21]. When welding steel materials, it is crucial to control the preheating temperature and employ appropriate heat treatment procedures to avoid temperature-induced changes in the base material’s properties and ensure compliance with quality requirements. The quality of welding has a significant impact on the structural integrity and safety of the products. However, relying solely on post-weld inspections is insufficient to guarantee that the quality meets the requirements. Proper control measures must be implemented throughout the manufacturing process, including pre-weld design, material selection, construction, and inspections. This comprehensive approach ensures that the quality of the welded joints meets the required standards [
22]. Especially for jacket-type substructures in offshore wind power, the structural components are predominantly composed of pipe steel. The fabrication of joint steel pipe openings is complex, making it impractical to use automated equipment for welding operations. Moreover, the joint design involves multiple orientations and various joint configurations such as T-shaped, Y-shaped, K-shaped, X-shaped, and saddle-shaped joints. These require skilled welding techniques performed by manual labor. The welded joints must undergo 100% non-destructive testing and meet the acceptance criteria [
23]. Consequently, the welding process planning, expertise, and proficiency of welding personnel significantly impact the quality control activities of the construction company. Welding is considered a specialized process within the quality control framework, highlighting the importance of the professional competence of the related technical personnel. Through the exploration of professional competencies, a comprehensive understanding of the required skill sets, including key job tasks, corresponding behavioral indicators, work outputs, knowledge, skills, and attitudes, can be achieved [
2,
24]. The purpose of this study is to explore and analyze the professional competencies required for welding technicians involved in offshore wind power substructure fabrication. The findings of this study will serve as a reference for future recruitment and training programs for technical personnel.
5. Discussion
After conducting three rounds of Delphi technique questionnaire surveys in this study, a convergence of expert opinions was achieved. After aggregating the statistical data from the third round, it was confirmed that the professional competence indicators for offshore wind power underwater foundation welding technicians consisted of three primary dimensions, ten sub-dimensions, and 75 indicator behavioral connotations.
5.1. First-Level Professional Competence Indicators (Dimension Indicators)
The three main dimensions of professional competence indicators for offshore wind power underwater foundation welding technicians were all rated as “extremely important” in this study. Among them, “professional skills” and “workplace attitude” were considered the most important, followed by “professional knowledge”. All the Delphi experts in this study ranked “professional skills” and “workplace attitude” as the highest in importance. This is mainly because the offshore wind power underwater foundation industry is one of the most important in domestic manufacturing, but there is a lack of design and manufacturing experience with underwater foundations in the country. Additionally, the welding process technology for underwater foundations has high requirements. Therefore, in the early stages of industry development, domestic companies need assistance from foreign wind farm developers to introduce design and manufacturing processes for underwater foundations. As a result, welding technicians in the offshore wind power underwater foundation field need to possess the basic competency requirements of “professional skills”, including equipment operation, welding practices, and welding inspection, to complete their work.
In addition to establishing the foundation of basic competencies through professional skills, individuals should possess traits listed under “workplace attitude” to enhance work efficiency and improve themselves in their professional field. These traits include process improvement, self-management, and teamwork. Although “workplace attitude” is considered an implicit core trait according to Spencer and Spence’s (2008) iceberg model theory and is less susceptible to change and development, it has a significant impact on job performance and learning outcomes. Therefore, to shorten the technology transfer and training period and immediately demonstrate job performance, all Delphi experts unanimously agree that when recruiting welding technicians in the offshore wind power underwater foundation field, priority should be given to “professional skills” and “workplace attitude” as professional competencies [
31].
Furthermore, although the importance of “professional knowledge” is slightly lower, it is still an indispensable explicit competency trait. It is easily perceptible and can be manifested through learning and training outcomes. As welding is a technical industry, professional technicians are the main practitioners in the manufacturing industry. Therefore, compared with “professional skills” and “workplace attitude”, the importance of “professional knowledge” is slightly lower. However, research suggests that if professional knowledge is combined with job execution requirements and accompanied by practical work skills, experience, endurance, problem-solving abilities, and work attitude, individuals can be competent in their roles, enhancing their personal value and the company’s competitiveness [
74].
5.2. Second-Level Professional Competence Indicators (Orientation Indicators)
The professional competence indicators for offshore wind power underwater foundation welding technicians consisted of 10 sub-dimensions. Among them, 8 sub-dimensions were rated as “highly important”. Based on the consensus of all Delphi experts, the four highest-ranked sub-dimensions were “equipment operation”, “welding practice”, “occupational safety”, and “quality standards”. Following them were “self-management” in second place and “teamwork” in third place.
The sub-dimensions of “equipment operation”, “welding practice”, “occupational safety”, and “quality standards” were considered essential competencies for underwater foundation welding technicians in the offshore wind power industry. Welding is a crucial part of metal processing, requiring the use of welding equipment to heat specific areas of two or more metal workpieces to the appropriate temperature, causing them to melt and fuse together. Given the lack of automated welding processes for most socket-type underwater foundation structures and the high demands of welding in the industry, a thorough understanding of welding equipment and professional welding skills and experience is necessary for underwater foundation welding technicians to successfully fulfill their job responsibilities.
The quality of welding directly affects the structural integrity and safety of products. Therefore, appropriate control measures must be implemented during the pre-welding design, material selection, and construction inspection processes to ensure that the post-welding workpiece meets the required quality standards. Welding is considered a special process within quality control activities, making the expertise of welding technicians even more important. Additionally, welding is classified as a 3K industry (dangerous, laborious, and dirty), highlighting the significance of occupational safety awareness and competence for underwater foundation welding technicians. By prioritizing occupational safety, not only can the well-being of employees be protected, but also the foundation for the company’s profitability can be maintained.
The second-ranked sub-dimension, unanimously deemed important by all Delphi experts, is “self-management”. As key human resources in the offshore wind power underwater foundation industry, welding technicians with good self-management abilities can not only enhance their own professional knowledge and skills but also conscientiously complete welding work and adhere to process specifications to ensure the delivered products meet quality requirements and improve work efficiency.
Lastly, the third-ranked sub-dimension identified by all Delphi experts was “teamwork”. This is primarily due to the high-risk working environment of underwater foundation welding. By paying attention to the safety of others during welding work, offering timely reminders, and providing assistance to colleagues, the occurrence of hazardous incidents can be reduced and the overall work performance during underwater foundation welding operations can be improved.
5.3. Third-Level Professional Competence Indicators (Detailed Indicators)
The professional competency indicators for offshore wind power underwater welding technicians consisted of 75 indicators and behavioral characteristics. Among them, 40 indicators were rated as “highly important”, while the remaining 35 were rated as “important”. The top three indicators in terms of importance were: (1) “Meet the non-destructive testing requirements and ensure quality”, (2) “Carrying out welding operations in quality standards”, and (3) “Ensures compliance with all requirements in the welding process”. Following closely were nine indicators, including “Ability to operate semi-automatic welding machines” in various positions (1G, 2G, 3G, 4G, 5G, 6G/6GR), and “Welder qualification and recording of welding parameters for welding. “The third highest-ranking indicators included “Prevention of illnesses and hazards associated with welding work”, “Selection of appropriate protective equipment for welding work”, and “Obtaining welding personnel qualifications in quality standards.“
The top three indicators in terms of importance aligned with the prioritization of the main constructs, namely welding practices, quality standards, and self-management. This indicates a unanimous agreement among the experts regarding the importance of these indicators. Analyzing the top three indicators in terms of importance, which included the ability to meet non-destructive testing requirements, adhere to quality standards, and follow welding process requirements for offshore wind power underwater foundations, as well as other important indicators such as proficiency in operating semi-automatic arc welding machines, passing certification tests for various welding positions, and practicing safety measures, it becomes evident that professional skills are the most crucial capabilities for welding technicians in the offshore wind power underwater welding process. Mastery of these skills, including obtaining certifications for specific welding positions, adhering to welding specifications throughout the process, and ensuring compliance with non-destructive testing standards, is essential for achieving the required welding quality according to European standards. Furthermore, selecting appropriate protective equipment in line with safety standards is crucial for minimizing occupational hazards and ensuring the well-being of personnel involved in welding operations.
6. Summary
This study conducted three rounds of Delphi technique questionnaire surveys, and consensus among all experts in the field of welding was reached. The construction of professional competence indicators for offshore wind power underwater foundation welding technicians was completed. The results of the dimension analysis indicate unanimous agreement among all Delphi experts that the dimensions of “professional skills”, “workplace attitude”, and “professional knowledge” are essential professional competence traits for offshore wind power underwater foundation welding technicians. Among them, “professional skills” and “workplace attitude” were considered the most important, followed by “professional knowledge”. The results of the sub-dimension analysis indicate unanimous agreement among all Delphi experts that the sub-dimension indicators of “equipment operation”, “welding practice”, “occupational safety”, and “quality standards” are of high importance. The next important sub-dimension indicators are “self-management”, “teamwork”, “welding inspection”, and “process improvement”, among others. After analyzing the behavioral content of the indicators, it is evident that the entire expert panel unanimously recognized the significant importance of each indicator. Notably, the highest average scores of 5 were achieved for the behavioral content related to “meeting non-destructive testing requirements and ensuring quality”, “performing welding operations in accordance with quality standards”, and “ensuring compliance with all requirements in the welding process”.
In the welding process of offshore wind power underwater foundations, emphasis is placed on the practical experience of technicians. Therefore, individuals should not only possess the ability to operate welding equipment, perform simple maintenance, and use tools but also complete welding work according to the specified requirements based on the welding positions of on-site components and perform relevant non-destructive testing standards to meet quality requirements. While working, it is essential to prioritize the occupational safety and potential risks associated with the work environment, avoiding irreversible consequences by pursuing short-term convenience. Lastly, the experts believe that welding technicians are practitioners, and ensuring welding quality is the most important professional skill and job responsibility. Therefore, the importance of aspects such as “metal materials” knowledge and “welding graphics” knowledge is relatively lower. However, if professionals can apply their expertise to meet work requirements and possess practical skills and experience in completing workplace tasks, it will further highlight their performance within the team. These findings align closely with the importance of various competencies identified through the review of relevant literature and analysis. They can serve as a reference for future development of professional competency indicators for welding technicians in offshore wind power underwater foundations. By utilizing these indicators, it will be possible to enhance the competence of personnel and increase industry competitiveness.