Respondents demographics profile
A sample of 50 people, where the percentage of men and women account for 90% and 10%, respectively, reflects how male-dominated the shipping industry is since only 5 women completed the survey questionnaire. In terms of age, the largest percentage of respondents is concentrated in the age group of 41 to 50 years, with a value of 36%. Respondents in the age group between 51 and 60 years account for 26% and respondents in the age group between 31 and 40 years of age present a percentage of 24%. Individuals whose age falls within the 61 and 70-year range have a rate of 8%, whereas those between the ages of 71 and above have a rate of 4%. Just 2% of people are in the first age group, which is people up to 30 years of age. Besides, it has been observed that a very high percentage of respondents (76%) hold a Master’s degree. As regards the shipping sector in which the participants are employed, it is observed that almost 90% of the sample work in classification societies and shipping companies or are ship-owners.
Results and discussion
The next step in the analysis of the data was to examine the significance of the hypothetical interactions of the research model. Appendix 1 includes the correlations for each grouped variable and displays the corresponding path coefficients for the proposed research model. For ease, the variables that have a major correlation are analysed and highlighted below.
Perceived Utility (PU) was significantly influenced by two exogenous factors to be deriving from Innovation Diffusion Theory: Observation (OB) (547 P < 0.001) and Complexity (CPX) (− 569 P < 0.001) supporting H5–1 and H3–1 hypotheses respectively. Specifically,
Observation has a positive impact on the Perceived Utility of the two alternative fuels, LNG and electricity. Appendix 1 presents the results of the correlation between the observability and the PU. All correlations are found to be statistically significant at 1%. The positive impact on the PU is reflected in the fact that participants feel that they should share the effects of the use of LNG and electricity, also that the majority have seen the ‘benefits’ of the two alternative fuels and, more significantly, it is reflected in the progress made by other shipping professionals. Besides, almost 80% of the participants assume that alternative LNG fuels and electricity will benefit them.
On the other hand, the Complexity factor has a negative effect on the Perceived Utility of both alternative fuels. Appendix 1 shows the correlations between Complexity and Perceived Utility. It has been reported that four of the five variables have a significant correlation. The results showed that the vast majority of participants, 82%, believe that alternative fuels have a complex fuel supply system. Moreover, complexity shows a negative impact because 1) too many participants conclude that alternative fuels’ performance remains low and 2) 54% of participants ‘strongly agree’ that the fragmented landscape at decision making at both global and national level has a negative impact of alternative fuels. Eventually, 90% of the participants agree that the various elements (components) within the system itself would lead to complexity.
The independent variables Safety and Risk Procedures (SPR), (738 P < 0.01) and Bunkering and Electrification (B&E), (− 4.00, P < 0.01) also have a major effect on the dependent variable Perceived Utility (PU). However, the result was contrary to what we assumed (H6–1 and H9–1) (rejected).
Safety procedures and risk have positively impacted the Perceived Utility of LNG and electricity, contrary to our assumptions. As presented in appendix 1, this variable SPR and the control variable, Perceived Utility, show a strong correlation of 1% (738 **). It is found that one relationship is statistically significant at 5%, and the other two are statistically significant at 1% (Appendix 1). The majority of participants believe that the inability to address safety issues in the early stages of development will harm the potential development and use of these alternative fuels. Likewise, a total of 64% agreed that the use of the two specific fuels poses a potential risk. However, a total of 30% disagreed with the view mentioned above. The question that divided and identified the most statistically significant correlation was the concern over LNG fuel’s extremely low temperatures. However, 66% of the respondents agree that they would feel safe on ships propelled by such alternative fuels, and almost 92% of respondents agree that risk identification studies were required.
Similarly, the results showed a negative impact (− 4.00) of the Bunkering and Electrification variable on the Perceived Utility of LNG and electricity, contrary to our hypotheses. The correlations are shown in Appendix 1, and it is observed that only one relationship is statistically significant at 1% (− 727 **). The results showed that the lack of bunkering guidelines divided the participants· 44%, agree with the above assumption, while 46% completely disagree with this assumption. Additionally, the assumption that an international standard for LNG bunkering should not be established, leading to the division of respondents (44% agreed vs. 42% disagreed). Concerning electricity, the results have shown that 68% of the respondents agree that advances in battery technology will give an advantage to future ship applications.
Results also showed that Perceived Utility (PU) was significantly influenced by Technology Challenges (TC) (− 846, P < 0.001) and Availability (AVL) (− 738, P < 0.001) supporting Hypotheses H12–1 and H13. – 1, respectively. The highest correlation concerning PU was evident in these two variables.
The technological challenges have a negative impact on the Perceived Utility of the two alternative fuels, LNG and electricity. Appendix 1 displays the correlations between the technological challenges and the control variable, PU. It is found that all relationships are statistically significant at 1% and, also, all have a very high correlation. The results showed that 76% of the participants agreed with the technological concern that the platform for the resolution of technical problems was still in its infancy. Furthermore, 84% of the respondents were concerned about space limitations on ships, such as larger tanks required for LNG storage, and almost half of the respondents (48%) were concerned about conversions to existing vessels in order to operate with those fuels. Nearly all of the respondents expressed concern with the fuel cell that is still in its initial stages. However, the failure of the two marine fuel development networks is a question that 46% of the participants fully agreed with, even though there was also a significant percentage (34%) who remained neutral on this assumption. It should be noted that, in light of the above issues, there are some concerns that alternative fuels cannot work well and cause problems.
Availability also has a negative impact on the Perceived Utility of the two alternative fuels that we are considering. It is observed (Appendix 1) that all relationships are statistically significant at 1% and, besides, all have robust correlations. The results revealed that there was no clear picture of the specific variable of availability, as there were conflicting views on issues related to the limited production capacity of LNG and electricity, the gaps in the quality standards for these alternative fuels and the fact that they may have poor stability, or that they would not be available in an adequate quality in the future. Furthermore, 34% of the sample were concerned about the well-known ‘Chicken and Egg’ dilemma, 22% opposed but also a significant one, in which 28% did not seem to know the issue and remained neutral, as shown in Fig. 2.
Also, Perceived Utility (PU) was found to be significantly influenced by the Infrastructure, (−,686, P < 0.001) and Economic and Financial Concern variables, (−,404, P < 0.001) supporting hypotheses H8–1 and H10–1 respectively.
The issue of Infrastructure shows a significant correlation with a negative effect on the Perceived Utility of LNG and electricity. Appendix 1 presents the findings of the analysis of the relationship between the Infrastructure and the control variable. Three of the five correlations of the infrastructure variable are statistically significant at 1%, and one is statistically significant at 5%. The results of the specific infrastructure variables are of great importance as they demonstrate a high degree of unanimity. Initially, almost all participants (98%) agree that the lack of infrastructure could pose obstacles to the alternative fuel supply chain, as seen in Fig. 3. About 80% of the participants ‘strongly agree’ with this statement. This finding highlights the urgent need for the development of infrastructure. In the same pattern, the results indicate that all participants agreed that there was a need for a specific standardisation of requirements for LNG refuelling facilities, the provision of electrical infrastructure in all types of ports, and a cold ironing infrastructure in terminals.
Besides, the findings indicate that all participants, except one person, agree that there was a need for a common standardisation of the requirements for LNG supply infrastructure. This ratio is statistically important at 5% (Appendix 1). It should be noted that all participants agree that the electrical infrastructure needs to accommodate all kinds of ports and that the infrastructure for cold ironing at marine terminals (ports) is a wise move. The only issue on which the views vary is whether users will be able to easily refuel their ships. Although a significant percentage (46%) strongly supported, the assumption, another significant percentage, (34%), disagreed.
The Economic and Financial Concerns factor also shows a significant correlation with a negative impact on the Perceived Utility of the two marine fuels, LNG and electricity. Appendix 1 presents the investigation results into the relationship between the independent variable (E&F) and the dependent variable (PU). It is noted that two out of five correlations are statistically significant at 1% and one is statistically significant at 5%. The results show that most respondents do not know whether or not the usage of alternative fuels will result in financial losses, as shown in the Fig. 4. However, 62% of the respondents believe that these alternative fuels will provide a positive budget for them.
Besides, the majority of participants (78%) believe that alternative fuels have higher operating costs, 90% believe that capital costs (for infrastructure, new ships) are huge investments and 68% believe that the initial investment required (propulsion systems, fuel management systems) is enormous. All these outcomes have resulted in this variable noting a significant correlation with a negative effect.
Compatibility is the only variable found to have a significant correlation on both control variables, Perceived Utility (PU) (456 p < 0.001) and Perceived Ease of Use (PEU) (476 p < 0.001) confirming cases H2–1 and H2–2 respectively. It is observed that there are three statistically significant correlations in Perceived Utility at 1% and another one statistically significant relationship at 5% (Appendix 1). The opposite is observed in Perceived Ease of Use, one (1) correlation being statistically significant at 1% and the other three (3) being statistically significant at 5% (Appendix 1).
Half of the respondents (50%) do not know whether or not the use of these two alternative fuels will be compatible with most aspects of their maritime activities. Simultaneously, there is the ambivalence between those who agree and those who disagree, up a 20% rate for both groups. However, 66% of the respondents agreed that LNG and electricity would be compatible with their shipping needs. Besides, it is imperative to emphasise that the highest percent of the participants (32%) respond that they ‘strongly agree’ that these alternative fuels, LNG and electricity are interoperable with other systems in existing vessels.
According to the TAM, the second dependent variable, Perceived Ease of Use (PEU), was found to be significantly affected by two external factors with a positive effect: the Relative Advantage (RAD) (613, P < 0.001) and the Trialability (TR) (485, P < 0.001) supporting hypotheses H1–2, H4–2, respectively. These hypotheses have been confirmed.
In particular, the Relative Advantage of these alternative fuels positively impacts the Perceived Ease of Use. The correlations of the independent variable with the control variable are shown in Appendix 1. It is observed that three of the five correlations are statistically significant at 1%. Almost all stakeholders in the shipping industry in Greece consider alternative fuels LNG and electricity to be sustainable (reduce emissions) at a rate of 92% and provide environmental benefits at a rate of 94%. Subsequently, most participants, 78%, consider that they are appropriate for the upcoming legislation (International Maritime Organization (IMO), n.d.). Moreover, a significant percentage of the participants, 30%, consider that LNG and electricity increase energy security. It has also been argued that alternative fuels are reliable, as shown in Fig. 5. These ratios show the superiority of the relative advantage of LNG and electricity over the current technology (MGO).
Trialability, the possibility of trial use, also positively affects the Perceived Ease of Use of both alternative fuels, LNG and electricity. The correlations of the trialability with the control variable can be found in Appendix 1. It is noted that four of the five relationships are statistically significant at 1%. The results showed that most participants believed that a trial would have a significant positive impact on the control variable since it was important before the decision was taken and that specific fuels have accumulated some good testing results abroad. Many stakeholders also agreed that it would be easy for them to find information on the use of the two alternative fuels, as shown in Fig. 5. However, there was a division between stakeholders regarding whether they could withdraw immediately after their use if they are not satisfied. It is observed that the people who agreed together with the people who completely disagreed with this assumption showed the same percentage (38%).
In addition, the Perceived Ease of Use (PEU) was found to be significantly affected by the positive impact of Governance Policy (GP) (381, P < 0.001) and Port Regulations (PR) (480, P < 0.001) supporting hypotheses H7–2 and H11–2 respectively.
Governance Policy has a positive impact on the Perceived Ease of Use of both alternative fuels, LNG and electricity. Two of the correlations are statistically significant at 1%, and two others are statistically significant at 5% (Appendix 1). Results have shown that the vast majority of participants (78%) believe that integrating and adapting the international legal framework for alternative fuels is necessary. Besides, 82% of respondents agree that a long-term policy framework should favour alternative fuels and that integrated strategies are required to boost alternative fuels usage. Of particular interest is the view of almost all participants (94%), that policies need to encourage the further improvement of fuels efficiency, as shown in Fig. 6, and that a significant proportion of participants (78%) believe that a regulatory timeline towards 2030 is needed.
While the Port Regulations factor is limited to literature, the results show that ports significantly impact the perceived ease of use of both marine fuels as mediators. Two of the relationships are statistically significant, at 1% (Appendix 1). The results showed that 84% of the sample stakeholders attach great importance to the role of ports because they agree that ports can lay down rules and address specific operational aspects. The 60% of participants who ‘Strongly agree’ that the port authorities should support the deployment of alternative fuels for shipping and 64% of participants who ‘Strongly agree’ that alternative fuels should be incorporated by the port authorities are also impressive. Finally, the majority of the participants (88%) agree that Port Services should be flexible to interact with the international guidelines of alternative fuels, as seen in Fig. 7.
Finally, concerning the last independent variable, Public Trust, the results have shown that there is no significant impact on public confidence issues in terms of future infrastructure opposition or that there is considerable uncertainty about the use of alternative fuels. Overall, the results show that respondents trust these alternative fuels and are not opposed to their use.
In addition, these results validated the existing research, which, as originally suggested by Davis 1989), established a strong relationship between Perceived Utility and Perceived Ease of Use. The two control factors in the model are considered to be significant factors in determining the acceptance of LNG and electricity as alternative fuels in Greece. Perceived Utility has a positive impact on Perceived Ease of Use and, respectively, the two alternative fuels, LNG and electricity. Appendix 1 presents the results from the investigation of their relationship. We observe that in Perceived Use two of the four relationships are statistically significant at 1% and one is statistically significant at 5%. In Perceived Ease of Use, out of the five relationships, one is statistically significant at 1% and three are statistically significant at 5%.
The ratios of the first controlling factor, Perceived Utility, are especially interesting. The overwhelming majority (90%) disagreed that the development of alternative fuels was a waste of resources. They also responded that the use of alternative fuels would increase the production (38%), efficiency (34%) and productivity (42%) of the company. Overall, as shown in Fig. 8, the majority (30%) “strongly agreed” that they consider the transition to alternative fuel technology useful.
Results on the issues of Perceived Ease of Use have shown that the majority of participants, with a 56% percentage of “Absolutely Disagree” that specialization in ships to be supplied with these alternative fuels would be easy and 70% in total disagreed that it would be easy to acquire the know-how for the use of alternative fuels. A total of 46% disagreed with the assumption that interaction with alternative fuels does not require mental effort. Nevertheless, it is of particular concern to the majority, 52%, who “strongly agreed” that, overall, they find it useful to embrace alternative fuels, as shown in Fig. 9.
Reliability
Reliability is a crucial element in the evaluation of the measuring instrument. Reliability concerns an instrument’s ability to measure consistently. Cronbach’s alpha, the most widely used objective measure of reliability, was computed using SPSS to test the measurement models. The general rule of thumb is that a Cronbach’s alpha of 0.7 and above is good. Our result is 0,869 for all of the 84 issues on the questionnaire. This showed that the measurement model exhibited a fairly excellent fit with the collected data. To sum up, the measurement model has achieved very satisfactory levels of reliability, convergent validity and discriminatory validity (see Table 2).