Investigating the Determinants of the Adoption of Solar Photovoltaic Systems—Citizen’s Perspectives of Two Developing Countries

Reviewer - 1

The manuscript of Ahmed and Khurshid is a very interesting and complete study about the determinants of adoption of solar photovoltaic systems - citizens' perspectives of Somalia and Pakistan.

We are grateful to you for realizing the topic interesting and encouraging us.

I´d like to suggest incorporating more illustrative figures and creating Supplementary Information to transfer some auxiliary Tables.

Please revise Table 1 – format column 4

Please format Table 2

Both tables have been formatted.

Could you convert some Tables into graphs? It would be more informative. The number of Tables (13) could be reduced.

We are thankful for your suggestion. Graphs are useful elements to understand the results quickly. However, we regret to inform you that tables are not converted into graphs, since tables can better explain the results in the current context.

Reviewer - 2

The paper can be improved with the following references:

1)Smart resilient city and IoT towards sustainability of Africa C. Lazaroiu, M. Roscia ICRERA 2018

2) Sustainability of decentralized renewable energy systems in Sub-Saharan Africa W Doorsamy, WA Cronje 

3) Better or worse? The role of solar photovoltaic (PV) systems in sustainable development: Case studies of remote atoll communities in Kiribati

K Mala, A Schläpfer, T Pryor - Renewable Energy, 2009 - Elsevier

We are thankful for your suggestion. However, we regret to inform you that suggested articles are not added since other relevant and credible articles have been referenced in the updated manuscript.

Reviewer – 3

In order to make Abstract more attractive, it is advised to add some quantitative result values as well. This will help readers to better apprehend the true meaning and significance of your results.

Results in terms of variance (R²) have been added in the Abstract as follows:

“In Somalia, the results revealed a variance of 49% in attitudes and 51% in intention to adopt SPVSs. In Pakistan, a variance of 60.1% in attitudes and 76.8% in intention to adopt SPVSs was found.”.

The introduction is weak at the moment and you need to make it clearer, indeed you need to better clarify the importance of this contribution for academics and practitioners, and also it is necessary to clearly explain the aim of the paper. It is very important to justify your contribution. Why is it important? Why did you use the PLS-SEM? What are your research questions? In some parts, I found this part and also some following parts too much deterministic, and also where are the most recent citations to really justify your research. Why do we study this topic? Is this topic a necessity? 

Why that? You need to better structure the introduction section providing much more support (previous studies and reports) to justify your study, also giving more details, regarding the focus on the construction industry and the specific methodology.

It is strongly advised to add stats and absolute values to justify the need of adoption of solar photo-voltaic system. 

Aim of the paper.

“Thus, the main aim of this study is to build an understanding of the factors that influence the adoption of solar PV systems by the consumers.”.

Importance of this contribution for academics and practitioners:

“The theoretical contributions are important because academicians can seek help and evidence in validating existing and developing new theories on technological innovation adoption.” … “The practical implications are important for practitioners for policy- and decision-making in removing the barriers and scaling up the adoption of solar PV systems in the understudied culture so that environmental quality and sustained economic development could be attained.”

What are the research questions?

“Motivated thus, we seek to answer the research question: What determinants influence the consumers’ adoption behaviour of solar (PV) systems in developing countries?”.

Why did you use the PLS-SEM?

“The PLS-SEM was adopted because it does not follow normal distribution assumptions, the study is exploratory where an extension of an existing structural theory was to be tested, it obtained parameter estimates by repeated least squares regression with a sin-gle dependent variable each time [78].”

Why is this study important?

“The conduct of this study is important to build the policy-makers understanding on the factors that significantly influence the consumers’ adoption of solar PV systems so that they can develop a policy instrument for scaling up the adoption among adopters and non-adopters both.”

Use previous studies to justify my study.

First, our focus was not on the construction industry. Second, the methodology has been described sufficiently to justify the conduct of this research.

Added stats and absolute values to justify the need for adoption of solar PV as:

“Contrary to this, solar PV systems can provide 11% of world’s green electricity production with a reduction of 2.3 Gigatonnes of GHGs emission each year [12].”.

“…increasing its power share by 43.14 times in past ten (10) years which was the highest capacity compared to other power-generation technologies [14].”

“…rapidly such as 13.8% in January 2014 to 17% in December 2014 [15],”.

“Moreover, an increase in the adoption of renewable energy sources like solar PV Systems is expected to reduce 30% of GHGs in the energy sector [12, 20].”

I suggest the authors to better explain their logical theoretical overview also considering more previous recent contributions partially focused on the phenomenon and its main determinants, analyzing in details some more studies. What is your theoretical framework? I know that you follow the main perspectives in the literature about the determinants of solar photo-voltaic adoption, but some elements need to be improved. Did you think about other possible techniques/methodologies? And what about other industries? Could you please clarify the link between your two phenomena in the analysis in the overall study?

Please try to be very clear and homogenize your literature review section also in the language. Maybe it should be useful for the readers to have a table summary about your early review. 

Moreoover, it is suggesed to comprehensively describe the solar inudtries, their current trends and conditions in regard to the "selected/choosen reference countries" in your paper i.e., Pakistan and Somalia.

What is your theoretical framework?

Our conceptual model is depicted in Figure 1.

Did you think about other possible techniques/methodologies?

Our study is based on hypothetico-deductive method, which generally adopts a similar approach used in this research article. Although there are other methods to collect data, such as secondary data, we preferred to conduct primary study/collect primary data. Moreover, there are certainly other techniques and software (like Artificial Neural Network Technique using IBM-SPSS to evaluate non-linearity) for data analysis; we preferred to use PLS-SEM using SmartPLS 3.3.9.

Homogenize your literature review section also in the language. Comprehensively describe the solar industries, their current trends and conditions regarding the “selected/chosen reference countries,” i.e. Pakistan and Somalia.

We have not focused on any industry but citizen adoption of Solar PV. Moreover, literature on solar PV adoption among consumers has already been presented in Section 2, which is quite relevant to the understudied phenomenon.

The main point related to the methodology section regards the adoption of the PLS-SEM approach, but also you use many other techniques, such as literature review, detailed field survey etc.,

In the research method you should put more details about the reasons for choosing the construction industry with most recent studies and reports to support that. Can you give more details about also the several techniques used? For instance, how did you make the literature review, is it a systematic literature review? Also, which program did you use for the literature analysis? How to finalized the population size, sample size, sampling technique?

Please, clarify and make changes in this section. In this section, I'd like to find the sub-paragraphs exactly with the title of the research steps described in the schematic representation of the methodology. 

Please, make changes about that.

Adoption of PLS-SEM approach?

“The PLS-SEM was adopted because it does not follow normal distribution assumptions, the study is exploratory where an extension of an existing structural theory was to be tested, it obtained parameter estimates by repeated least squares regression with a single dependent variable each time [78].”

Put more details about the reason for choosing the construction industry.

Since we have not chosen the construction industry but rather citizens/households, there is no need to give more details about the reason for choosing the construction industry.

How did you do the literature review? Which program did you use for the literature analysis?

PLS-SEM was used to perform quantitative analysis (reliabilities and validities of constructs, testing of hypotheses, and MICOM analysis) after collecting the citizens' data and designing the survey questionnaire. Other techniques, such as literature review, detailed field survey, etc., were not to perform quantitative analysis. Moreover, we have reviewed the quantitative studies (stored and managed using Endnote) that focused the Solar PV adoption by households/citizens/consumers.

How do we finalize the population size, sample size, and sampling technique?

Sample Size: “To determine the minimum sample size, we used G*Power software, setting statistical power of 0.95 and effect size of 0.15, probability level of 0.05, and eight (8) variables [73]. Putting these parameters, this study required minimum sample size of 160.”

Population: “According to sample size guidelines of Sekaran and Bougie [74], results of 384 responses can be generalized to one million population. Therefore, 464 responses are sufficient for a population of over one million.”

Sampling Technique: “…,, since the feedback or opinion of the adopters of solar systems was to be considered.”

The results section needs to be better developed, especially regarding comparison to previous research on the topic. I didn't find many cited previous studies specially from Pakistan and Somalia, asian and african countries. Please, try to be much clearer and more linear. 

Also, I suggest to make a separation between the results and discussion parts. It should be better to put your discussion after the description of the results, but you need to better structure and stress your results for the discussion. Discussion section, as already said, needs to be better developed especially giving much more citations from the past.

The results and Discussion sections were already separate. In this respect, only the findings of the current study were presented in the Result Section.

The discussion section is separate and sufficiently backed up by citing previous studies in Asian and African contexts. Please see highlighted changes in discussion section.

The conclusion section needs to be reworked. Please, improve your concluding remarks, your final considerations need to be very strong and clear.  

Thus, the conclusion section needs to be expanded evidencing also more the managerial, practical and policy implications and future research perspectives. You don't give any suggestions for managers and policy makers in the discussion section, but you need to better explore and explain this part too here.

To make the concluding remarks strong and clear, we have added, “In current times, In current times, the human is facing global warming as the most complex issue along with sustainable development as the biggest challenge [18]. In this connection, the World is increasingly recognizing environmental concerns. With the advancement of information and communication technologies, as people get aware of these con-cerns, they show their interests in using latest technologies that best fit in their culture or improving quality of life. We also see that environment-friendly innovations are being introduced in local and international markets and consumers are largely adopt-ed them. The adoption of solar PV systems by the consumers can be scaled up if an un-derstanding of the factors influencing adoption can be developed. Thus, this study’s primary objective was to build an understanding of the factors that influence the adoption of solar PV systems by the consumers.”

Hopefully, it will serve the purpose.

We didn't give any suggestions for managers and policy-makers in the Discussion section except in sub-sections, i.e. Theoretical and Practical implications.

Should we put the implication section in the Conclusion section? Please advise.

Moreover, limitations and future directions have also been extended as “Some other demographics can also be probed to examine their impact on adoption such as (1) how many days/hours electricity backup remains, (2) how much load or capacity (300KVA, 500KVA, 1000KVA and so on) of solar PV systems they are using to meet their needs. Fourth, the MICOM analysis with respect to urban and rural areas can also be performed for deeper insights. Although the ratio of consumers (17% for Somalia and 8% in Pakistan) who are not willing to install solar PV system even if it is subsidized is not significant, there can be a need to investigate the reasons on why they are not willing to install solar PV system [34].”.

Reviewer – 4

1

It is well written and structured, with an adequate approach and methods. However, some more comments could be added to enrich the conclusions and eventual future works, for example the impact expected on the results due to the majority of the users interviewed were using the solar systems for a short period (0 to 3 years). Also, why trust not being revealed as a strong determinant of solar PV systems in Somalia, differently from Pakistan.

Although reasons for the insignificant effect of trust were presented in the manuscript, further reason has been mentioned as “Moreover, the market manipulation with regard to counterfeited solar products and their prices can be another reason for an insignificant influence of trust on developing intentions in African consumers, since they cannot get reliable electricity supply throughout the day and year without good quality solar products [17, 19].”.

Limitations and future work have also been extended. Please see Section 7, Conclusion and Limitations.

2

In my opinion the manuscript could be published in Sustainability, because brings useful information for future efficient dissemination / implementation of solar energy in developing countries.

Thank you for recognizing our efforts and recommending the article for publication.