Investigation of Potential of Solar Photovoltaic System as an Alternative Electric Supply on the Tropical Island of Mantanani Sabah Malaysia

Round 1

Reviewer 1 Report

The manuscript presents an analysis of the possibility of using a photovoltaic system as an energy source on Mantanani Island. Although the subject is worth investigating, the Authors show relatively simple calculations of yearly (monthly as well) irradiation (1447 kWh/y) and daily energy usage based on the resident’s equipment and usage period (7.5 kWh/d).  Such data can be easily generated from website platforms (e.g. PVGIS) for any location. Figs. 6-8 with wide descriptions of Sun paths, Sunrises, etc. are useless. They are very common and cannot be the core of the results section of a scientific paper. The Authors proposed a scheme of the PV system (Fig. 9) without any details (e.g. battery size). There is no prognosis of daily (monthly) energy production by the PV system as well as no discussion of energy balance (production vs. consumption). Pay attention that the highest energy usage is between 17:00 and 21:00 (Fig. 10). For this reason, the PV system should be discussed in more detail (with all details related to modules, batteries, as well as simulations of energy production including energy losses). In my opinion, the manuscript contains general descriptions without deep research of the proposed topic and in its form cannot be published in a scientific journal.

Some other comments for Authors

L. 12: Explain this line in more detail (add units, explain the value of 0600?)

L. 220-228 and others: Use the following format for time notation: 18:00 instead of 1800

L. 188-193: All variables should be italicized

L 22, 249: Compare the b value of 1.2 MWh/m²/y presented in line 22 with the value of 1447 kWh/m²/y presented in line 249. It should be the same value. Verify and correct.

L. 249 - 251: Something is wrong with the calculation of sun hours. 4.05 hours at the intensity of 1000 W/m² mean 4050 Wh (4.05 kWh/m²).

Eq. 2: The format of equation (T.R.D.) is probably wrong. The same in eq. (3)

Fig. 8. It is better to use a 2D plot than 3D for higher visibility

Author Response

Dear reviewer,

We are thankful for the detailed comments from you and we have thoroughly revised the manuscript as required. For your reference, our feedback are written in blue text.

The manuscript presents an analysis of the possibility of using a photovoltaic system as an energy source on Mantanani Island. Although the subject is worth investigating, the Authors show relatively simple calculations of yearly (monthly as well) irradiation (1447 kWh/y) and daily energy usage based on the resident’s equipment and usage period (7.5 kWh/d).  Such data can be easily generated from website platforms (e.g. PVGIS) for any location. Figs. 6-8 with wide descriptions of Sun paths, Sunrises, etc. are useless. They are very common and cannot be the core of the results section of a scientific paper. The Authors proposed a scheme of the PV system (Fig. 9) without any details (e.g. battery size). There is no prognosis of daily (monthly) energy production by the PV system as well as no discussion of energy balance (production vs. consumption). Pay attention that the highest energy usage is between 17:00 and 21:00 (Fig. 10). For this reason, the PV system should be discussed in more detail (with all details related to modules, batteries, as well as simulations of energy production including energy losses). In my opinion, the manuscript contains general descriptions without deep research of the proposed topic and in its form cannot be published in a scientific journal. 

This paper has been improvised accordingly 

L12: Explain this line in more detail (add units, explain the value of 0600?)

This matter has been resolved in the manuscript

L220-228 and others: Use the following format for time notation: 18:00 instead of 1800

The time notation was resolved as suggested by the reviewer by using the notation

L188-193: All variables should be italicized

All variables was italicized

L 22, 249: Compare the b value of 1.2 MWh/m2/y presented in line 22 with the value of 1447 kWh/m2/y presented in line 249. It should be the same value. Verify and correct. 

The figure in abstract has been revised accordingly. 

L249 - 251: Something is wrong with the calculation of sun hours. 4.05 hours at the intensity of 1000 W/m2 mean 4050Wh(4.05 kWh/m2).

We have checked this calculation and found that this calculation is correct. The determination of PSH was done as follows: 

1. measurement of irradiance intensity every hour throughout the year
2. the total radiation intensity per month is determined
3. the value of the monthly intensity (no.2) divided by 1000 to get the number of hours equal to the intensity of 1000 W/m2
4. the average annual PSH is estimated by adding PSH (no.3) each month and dividing by 12.

The value of PSH is different from the total DNI. The amount of DNI is calculated as follows: 

1. measurement of radiation intensity every hour throughout the year
2. the total radiation intensity per month is determined
3. the value of the intensity (no.2) of each month is added to obtain the total annual DNI

PSH is the daily insolation value while DNI is the total solar energy in a year.

Eq. 2: The format of equation (T.R.D.) is probably wrong. The same in eq. (3)

Format for equations 2 and 3 has been corrected. Based on the instruction, the format for the equation is font type Palatino Linotype and size 10. 

Fig. 8. It is better to use a 2D plot than 3D for higher visibility

Fig. 8 has been replace to 2D plot.

Reviewer 2 Report

This is a good empirical article. The issue of investigation on potential of solar photovoltaic system (SPS) in Malaysia is important, because we need to see more articles on the SPS and its benefic impact on the local and national economy especially coming from the Global South. 

There are several issues on which the authors have to do during the revision.

At the moment the introduction includes the theoretical background and it would be good for the readers of this article to see a clear deliniation between the aims of this article and the literature review. Therefore, a literature review section is recommended to be drawn.

It is also important to write 1-2 sentences on the importance of this study at international and regional level (eg. south Asia) and what this study brings new in the current photovoltaic energy literature.

The literature review is quite scarce, there are only 24 mentioned references. I would like to see more studies mentioned on photovoltaic/solar energy, see for instance numerous articles on solar energy published in journal Energies and in other energy-related journals. Also, there could be added some works on related issues with photovoltaic or broader renewable industries development. For instance, aspects of foreign direct investments and/or local Malaysian investments in the field. It can be mentioned cases of foreign direct investments in different countries (eg. see Ang (2008) who wrote on FDI in Malaysia in Journal of policy modeling, or even C.G. Lee who wrote about FDI in Malaysia in journal Applied Economics, 2009. See also cases of FDI in other countries worldwide, see the chapter entitled Foreign direct investment and social risk in Romania: Progress in Less-favoured areas, in book entitled: David Turnock (Edition) Foreign Direct Investment and Regional Development in East Central Europe and the Former Soviet Union, Routledge, 2017, pp. 305-348 etc). It can be mentioned also that in some developing countries patterns of corruption from political elites could undermine proper development of local economies including renewables (for issues of corruption-energy nexus it can be given examples as of Arminen et al, 2019 published in journal Energy Economics, and see Boamah article on renewable and classical energy in Africa published in journal Energy Research & Social Science. Also, corruption of economy in former communist countries of Eastern Europe could be mentioned, see the article on corruption and conflagration in Bucharest published in journal Urban Geography 41(3) in 2020).

The results are nicely presented by the authors, but conclusions could be enlarged because there are many other findings in this article. Also, follow-up research or how other authors can develop further the outcomes of this article could be mentioned. Some policy recommendations would be also welcome. For instance it can be mentioned that in comparison to contested resource exploitations worldwide (see resource curse and their contestation in former Soviet states by P. J. Luong and E. Weinthal in Comparative Political Studies, 2001 and see a recent article by Nicoleta Risteiu et al, 2021 in journal Eurasian Geography and Economic), solar energy brings much more benefits for local and national economies.

Author Response

Dear reviewer,

We are thankful for the detailed comments from you and we have thoroughly revised the manuscript as required. For your reference, our feedback are written in blue text.

This is a good empirical article. The issue of investigation on potential of solar photovoltaic system (SPS) in Malaysia is important, because we need to see more articles on the SPS and its benefic impact on the local and national economy especially coming from the Global South.  

There are several issues on which the authors have to do during the revision. 

At the moment the introduction includes the theoretical background and it would be good for the readers of this article to see a clear deliniation between the aims of this article and the literature review. Therefore, a literature review section is recommended to be drawn. 

It is also important to write 1-2 sentences on the importance of this study at international and regional level (eg. south Asia) and what this study brings new in the current photovoltaic energy literature. 

The literature review is quite scarce, there are only 24 mentioned references. I would like to see more studies mentioned on photovoltaic/solar energy, see for instance numerous articles on solar energy published in journal Energies and in other energy-related journals. Also, there could be added some works on related issues with photovoltaic or broader renewable industries development. For instance, aspects of foreign direct investments and/or local Malaysian investments in the field. It can be mentioned cases of foreign direct investments in different countries (eg. see Ang (2008) who wrote on FDI in Malaysia in Journal of policy modeling, or even C.G. Lee who wrote about FDI in Malaysia in journal Applied Economics, 2009. See also cases of FDI in other countries worldwide, see the chapter entitled Foreign direct investment and social risk in Romania: Progress in Less-favoured areas, in book entitled: David Turnock (Edition) Foreign Direct Investment and Regional Development in East Central Europe and the Former Soviet Union, Routledge, 2017, pp. 305-348 etc). It can be mentioned also that in some developing countries patterns of corruption from political elites could undermine proper development of local economies including renewables (for issues of corruption-energy nexus it can be given examples as of Arminen et al, 2019 published in journal Energy Economics, and see Boamah article on renewable and classical energy in Africa published in journal Energy Research & Social Science. Also, corruption of economy in former communist countries of Eastern Europe could be mentioned, see the article on corruption and conflagration in Bucharest published in journal Urban Geography 41(3) in 2020).

A paragraph has been included to increase the number of references and discuss the points suggested by the reviewer 2. Elaboration in this paragraph focuses on the issue of local and foreign direct investment FDI to the energy industry in Malaysia and internationally. Almost all of the references suggested by reviewer 2 were included including other relevant references. At the end of this paragraph has touched on issues such as conflict and corruption that affect national development and FDI in general. This paragraph is in L71 - L99. 

The results are nicely presented by the authors, but conclusions could be enlarged because there are many other findings in this article. Also, follow-up research or how other authors can develop further the outcomes of this article could be mentioned. Some policy recommendations would be also welcome. For instance it can be mentioned that in comparison to contested resource exploitations worldwide (see resource curse and their contestation in former Soviet states by P. J. Luong and E. Weinthal in Comparative Political Studies, 2001 and see a recent article by Nicoleta Risteiu et al, 2021 in journal Eurasian Geography and Economic), solar energy brings much more benefits for local and national economies. 

This has been explained in final paragraph in the conclusion of this manuscript

Reviewer 3 Report

This study attempts to evaluate the potential use of photovoltaic solar system in Mantanani Island, Malaysia. The topic is interesting and the methodology is suitable for the readers. However, some parts of this paper still need to be revised extensively for the readers of this journal.

First, I suggest that the authors need to revise the verb tense in the abstract part due to this work has finished yet. For instance, in line 9, this article "will" report…. 

Second, I suggest that the authors should summarize the research gaps on literature review in the first section and highlight the research contributions compared the existing studies (discussions are also required).

Third, I suggest that a conclusion section is needed to propose some policy implications for Mantanani Island, Malaysia. 

Author Response

Dear reviewer,

We are thankful for the detailed comments from you and we have thoroughly revised the manuscript as required. For your reference, our feedback are written in blue text.

 This study attempts to evaluate the potential use of photovoltaic solar system in Mantanani Island, Malaysia. The topic is interesting and the methodology is suitable for the readers. However, some parts of this paper still need to be revised extensively for the readers of this journal. 

First, I suggest that the authors need to revise the verb tense in the abstract part due to this work has finished yet. For instance, in line 9, this article "will" report

This manuscript has been revised accordingly

Second, I suggest that the authors should summarize the research gaps on literature review in the first section and highlight the research contributions compared the existing studies (discussions are also required).

A paragraph has been included which discusses related to FDI and energy policy in Malaysia. We found out this has been missing in our previous discussion.

Third, I suggest that a conclusion section is needed to propose some policy implications for Mantanani Island, Malaysia.

This matter has been addressed in conclusion part

Reviewer 4 Report

The manuscript "Investigation on Potential of Solar Photovoltaic System as an Alternative Electric Supply at Tropical Island of Mantanani Sabah Malaysia" provides an example of a technoeconomic assessment for a remote location. The work is interesting and the topic is of importance, however, the manuscript is not suitable for publicaiton until the following points can be addressed:

• [62] – A decrease in energy costs by 11-euro cent per what?
• There are grammatical errors throughout the document.
• It is difficult to read the image in Figure 4, and this figure does not add much value. The authors may consider removing it.
• Details about the questions and responses for the questionnaires distributed among the residents should be provided.
• The payback period in equation three does not consider the income that the homestay already would have without the solar installation. An accurate analysis would have to consider that the homestay generates some revenue without the installation, but that this revenue increases (perhaps due to the ability to charge more or due to a greater number of overnight stays). The increase in revenue due to the installation, rather than TRD, should be used in the denominator of equation three.
• The units are missing on many numbers – use the degrees symbol for angles and use proper notation to indicate when the number is referring to an hour of the day.
• An example and cost breakdown for the type of PV panel, charge controller, battery and inverter should be given.
• For a given size of battery, will there be any times throughout the year for which there will not be enough sun to keep the battery changed (e.g. a number of consecutive days of minimal amounts of sunshine?).
•  

Author Response

Dear reviewer,

We are thankful for the detailed comments from you and we have thoroughly revised the manuscript as required. For your reference, our feedback are written in blue text.

The manuscript "Investigation on Potential of Solar Photovoltaic System as an Alternative Electric Supply at Tropical Island of Mantanani Sabah Malaysia" provides an example of a technoeconomic assessment for a remote location. The work is interesting and the topic is of importance, however, the manuscript is not suitable for publicaiton until the following points can be addressed: 

[62] – A decrease in energy costs by 11-euro cent per what?

11-euro cent per kWh. The term “per kWh” is already included in the verse. Sorry for the mistake and thank you 

There are grammatical errors throughout the document.

The grammatical errors has been corrected accordingly 

It is difficult to read the image in Figure 4, and this figure does not add much value. The authors may consider removing it.

Figure 4 has been removed.

Details about the questions and responses for the questionnaires distributed among the residents should be provided.

The question and responses report has been prepared. please refer to the pdf, filename “questionnaires report.pdf”. 

The payback period in equation three does not consider the income that the homestay already would have without the solar installation. An accurate analysis would have to consider that the homestay generates some revenue without the installation, but that this revenue increases (perhaps due to the ability to charge more or due to a greater number of overnight stays). The increase in revenue due to the installation, rather than TRD, should be used in the denominator of equation three. 

Additional analysis was included to assess profitability based on the increase in tourists and the number of daily rentals. The increase in profits was based on two references found, saying the increase in tourists to the islands of the state was 2 % per annum. This additional analysis is also based on two solar system installation costs, namely the minimum cost (MYR 37,036) and the maximum (MYR 56,036). The results are shown in the graph, positive values are achieved by the minimum and maximum cost values after 10.1 and 15.2 years, respectively. 

The units are missing on many numbers – use the degrees symbol for angles and use proper notation to indicate when the number is referring to an hour of the day.

An example and cost breakdown for the type of PV panel, charge controller, battery and inverter should be given.>> Pian 

A table  was added to show PV system cost breakdown namely Table 4.

For a given size of battery, will there be any times throughout the year for which there will not be enough sun to keep the battery changed (e.g. a number of consecutive days of minimal amounts of sunshine?).

The capacity of the battery bank is 8.4 kWh, which is 7 units of 100 Ah 12V batteries. This amount is enough to cover the time of irradiance intensity at least in a year. The lowest solar insolation was identified in January at 3.2 PSH. The solar insolation range is small because Malaysia is located near the equator. This position results in the number of hours of day and night is almost the same and the amount of solar insolation is stable throughout the year. So, this PV system is designed to operate with a number of consecutive days of minimal amounts of sunshine around 1 only. 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The manuscript has been partly revised. However, in its form, it is still not a scientific paper for the same reasons I showed in my previous review. A relatively simple analysis related to solar radiation or energy consumption was provided.  No prognosis of PV energy production was shown as well as energy balance (e.g. monthly or daily comparison between PV energy production and energy consumption). I would recommend providing the results of PV energy production and discuss with the energy consumption. 

Author Response

Dear Reviewer,

Thank you for your insightful comments. We have revised our paper accordingly and feel that your comments helped clarify and improve our writing. Please find our response to the reviewer's specific comments below:

The manuscript has been partly revised. However, in its form, it is still not a scientific paper for the same reasons I showed in my previous review. A relatively simple analysis related to solar radiation or energy consumption was provided.  No prognosis of PV energy production was shown as well as energy balance (e.g. monthly or daily comparison between PV energy production and energy consumption). I would recommend providing the results of PV energy production and discuss with the energy consumption.

The prognosis of energy production and energy balance was inserted in Methodology, and Result and Discussion section. The analysis is monthly and annual basis. 

L262 – L306, L426 – L450.

Reviewer 2 Report

Authors have improved the content of this paper, but there are some small issues which have to be solved.

First, several references in the reference list do not have page numbers and doi numbers, see reference 6 and 17.

Also, it is recommended to cite the family name and not the personal name of some authors (for instance Remus et al. is not correct). 

Then, before the conclusions or in the conclusions of this paper it is mandatory to add a paragraph in which it must be linked the results of this study to the literature review worldwide. By doing this it will be shown the implications of the results of this study in the international literature.

Finally, I still think the reference list is too short, it is now made up of 32 references. It must have at least 50 references on solar energy (e.g. there are plenty of other solar energy studies in journal Energies which can be cited) and on energy-related alternative development issues worldwide. For instance, as I presented previously in my first review it can be mentioned in the middle part of the introduction that solar energy can be a tool for alternative development by rejuvenating former mining areas which now are or could be included in World Heritage sites (see Risteiu et al, 2021, doi: 10.1080/15387216.2021.1913205) and can be given few other examples of studies on rejuvenating former poor or less-favoured areas (see Geal's study https://doi.org/10.1016/j.erss.2018.04.035 and see an FDI study on less-favoured areas - https://publons.com/publon/27494035/).

Author Response

Dear Reviewer,

Thank you for your insightful comments. We have revised our paper accordingly and feel that your comments helped clarify and improve our writing. Please find our response to the reviewer's specific comments below.

Several references in the reference list do not have page numbers and doi numbers, see reference 6 and 17.

Reference 6. Doi added (L556 – L558)

Reference 17. No doi, it is a thesis from University of Nottingham (L571)

Also, it is recommended to cite the family name and not the personal name of some authors (for instance Remus et al. is not correct).

Remus change to Crețan. (L87,L94)

Then, before the conclusions or in the conclusions of this paper it is mandatory to add a paragraph in which it must be linked the results of this study to the literature review worldwide. By doing this it will be shown the implications of the results of this study in the international literature.

The literature review and result of this study have been linked in the way of emphasis that this study has contributed and focused on the research gap stated in the literature. The author has also stated the contribution of this study to the research gap stated in the introduction. (L179 – L206, L527 – L534)

Finally, I still think the reference list is too short, it is now made up of 32 references. It must have at least 50 references on solar energy (e.g. there are plenty of other solar energy studies in journal Energies which can be cited) and on energy-related alternative development issues worldwide. For instance, as I presented previously in my first review it can be mentioned in the middle part of the introduction that solar energy can be a tool for alternative development by rejuvenating former mining areas which now are or could be included in World Heritage sites (see Risteiu et al, 2021, doi: 10.1080/15387216.2021.1913205) and can be given few other examples of studies on rejuvenating former poor or less-favoured areas (see Geal's study https://doi.org/10.1016/j.erss.2018.04.035 and see an FDI study on less-favoured areas - https://publons.com/publon/27494035/).

References has been added at least 50 references as stated by the reviewer.

The author finds to relate the storyline of this manuscript to some of the issues suggested by the reviewer quite challenging. However, author has touched on the matter in general and has cited the suggested references.

(L80 – L100)

Reviewer 3 Report

The authors has revised the manuscript carefully and proposed a better version. However, some parts of this paper still need to revise in advance for the readers of this journal.

I suggest that the authors should summarize the research gaps on literature review in the first section and highlight the research contributions compared the existing studies (discussions are also required) in former review report. The authors’ response is as following: “A paragraph has been included which discusses related to FDI and energy policy in Malaysia. We found out this has been missing in our previous discussion.” Thank you for authors’ efforts to address the issue of research gaps. However, the topic this article is to evaluate the potential use of photovoltaic solar system in an island, not highly related to the FDI issue. I still suggest that the authors compose the relevant studies that highly related to the topic of this article and then highlight the research gaps. Finally, the authors need to make a comparison between existing studies and research findings in Conclusions section.

Author Response

Dear Reviewer,

Thank you for your insightful comments. We have revised our paper accordingly and feel that your comments helped clarify and improve our writing. Please find our response to the reviewer's specific comments below:

I suggest that the authors should summarize the research gaps on literature review in the first section and highlight the research contributions compared the existing studies (discussions are also required) in former review report. The authors’ response is as following: “A paragraph has been included which discusses related to FDI and energy policy in Malaysia. We found out this has been missing in our previous discussion.” Thank you for authors’ efforts to address the issue of research gaps. However, the topic this article is to evaluate the potential use of photovoltaic solar system in an island, not highly related to the FDI issue. I still suggest that the authors compose the relevant studies that highly related to the topic of this article and then highlight the research gaps. Finally, the authors need to make a comparison between existing studies and research findings in Conclusions section.

Author has relate the discussion with the topic by studying necessary scientific assessment of potential PV system as alternative power supply for the island.

Compare existing study with research findings are shown (L494 – L509)

Research gap of this study was identified (L190 – L206)

Contribution highlighted at the end of this manuscript (L527 – L534)

Reviewer 4 Report

The paper has been improved, although further work is required before publication can be recommended. Further comments are provided below.

• There are still many grammatical errors throughout the manuscript.
• [93] and [97] The 2 should be a subscript instead of a superscript.
• [118] – describe what is meant by island mode.
• Figure 4 does not properly show the methodology used. For example, why is an arrow going from “solar energy source” into “basic energy profile” when items such as the hourly load profile do not require input about the solar energy source. The figure should match a clear explanation of the methods provided in the text.
• The authors mention that there is a questionnaires report, however this does not seem to be indicated in the manuscript.
• The format of the text used in Equations 2 and 3 are different.
• There are no units on the color bar in Figure 6.
• What interest rate is assumed in the economic analysis. If it is zero then justification should be given.

Author Response

Dear Reviewer,

Thank you for your insightful comments. We have revised our paper accordingly and feel that your comments helped clarify and improve our writing. Please find our response to the reviewer's specific comments below:

There are still many grammatical errors throughout the manuscript.

This manuscript has been reviewed to improve the grammar.

[93] and [97] The 2 should be a subscript instead of a superscript.

Corrected accordingly (L89, L94)

[118] – describe what is meant by island mode.

Island mode refers to a system that is operating independently to the utility and can also be commonly known as “off-grid” generation. Island mode refers to a plant such as solar system that is not, or no longer, connected to other power plants or utility source. Remote towns, mine sites and island often have island mode power plants as opposed to larger cities and dense population areas where multiple power plants provide power to a grid. Island mode units also act as standby or backup units to provide electricity.

Figure 4 does not properly show the methodology used. For example, why is an arrow going from “solar energy source” into “basic energy profile” when items such as the hourly load profile do not require input about the solar energy source. The figure should match a clear explanation of the methods provided in the text.

Figure 4 was improved and change. Elaboration was provided to clearly explain the methodology. (L215 – L328)

The authors mention that there is a questionnaires report, however this does not seem to be indicated in the manuscript.

A paragraph added to elaborate the questionnaire in Methodology and Result and Discussion section. Example of question also provided in Table 2. (L235 – L249, L371 – L390)

The format of the text used in Equations 2 and 3 are different.

Corrected accordingly. (L254, L270, L276, L286, L299, L314, L326)

There are no units on the color bar in Figure 6.

Color bar added for Figure 6. (L358)

What interest rate is assumed in the economic analysis. If it is zero then justification should be given.

Its zero or no interest rate. The technoeconomic analysis doesn’t consider any bank loan or other interest rate related scheme. It is straight forward calculation which considering the initial cost and operation cost.

Round 3

Reviewer 1 Report

The authors have revised the manuscript according to my comments. Although I still think that the presented results of the research suffer from a lack of novelty I would like to give the chance to publish the paper. Some minor comments were listed below.
+ lines 520 - 525; Consider using past tenses (instead of will, is, etc.),
+ pay attention that all variables should be italicized,
+ line 670: DNI here is rather an irradiation (than irradiance); check the unit
+ Fig. 8: The unit Wh is wrong. it should be kWh 
+ Fig. 11: in my opinion, the efficiency of consumption is confusing. it should be PV energy consumption (in %) as it is in eq. (5). The second y-axis could be provided.
+ Fig. 12: do you mean 'difference'?

Author Response

Dear Reviewer,

Thank you for your insightful comments. We have revised our paper accordingly and feel that your comments helped clarify and improve our writing. Please find our response to the reviewer's specific comments below:

+ lines 520 - 525; Consider using past tenses (instead of will, is, etc.),

The paragraph change to past tenses. L237-241

+ pay attention that all variables should be italicized. 

Eq. (1), (2), (3), (4), (5), (6), (7) and all the variables such as PP and ROI.

+ line 670: DNI here is rather an irradiation (than irradiance); check the unit

Irradiance change to Irradiation. The unit checked. L264

+ Fig. 8: The unit Wh is wrong. it should be kWh

Wh change to kWh. L349

+ Fig. 11: in my opinion, the efficiency of consumption is confusing. it should be PV energy consumption (in %) as it is in eq. (5). The second y-axis could be provided.

“Efficiency of consumption” change to “PV energy consumption”. We add second y-axis and some info at the legend axis so the reader can differentiate which y-axis for which series. L431.

+ Fig. 12: do you mean 'difference'?

Different change to difference. L431

Reviewer 4 Report

 The manuscript has been greatly improved, although there is much room for further improvements. See comments below:

• The writing has been improved, but there are still grammatical errors throughout the document.
• The sentence on lines 101 and 102 is unclear and should be rephrased.
• on line 135 put “FiT” in brackets.
• [207] – could contribute between 5.14% and 24.6% of what energy?
• [220] – lighting is mentioned twice (as part of both the 83% and the 17%)?
• [283] – should be “The number of residents”
• [386] – should be feed instead of fit – but the acronym should be used here.
• Figure 4 could still be improved further – wouldn’t the energy balance be done before the technoeconomic analysis? (the way they are presented in the figure makes it seem they are done in parallel).
• It seems odd to have a category for 0-18 year olds for answering the survey – surely the age of the youngest participant can replace the 0.
• The information provided in Figure 6 and the surrounding discussions are not a result of the research done in this paper. Rather, it is background information that was retrieved from other sources. This must be removed from the results section.
• [1143] – explain what is meant by the energy consumption range?
• In Figure 12 I think you mean difference instead of different. This should be changed and explain what it is in the figure caption.

Author Response

Dear Reviewer,

Thank you for your insightful comments. We have revised our paper accordingly and feel that your comments helped clarify and improve our writing. Please find our response to the reviewer's specific comments below:

The sentence on lines 101 and 102 is unclear and should be rephrased.

The sentence was rephrased. L47-48

on line 135 put “FiT” in brackets.

Bracket added. L82

[207] – could contribute between 5.14% and 24.6% of what energy?

…could contribute between 5.14% and 24.6% of total energy generation. L104-105

[220] – lighting is mentioned twice (as part of both the 83% and the 17%)?

Yes. The 83 % for lighting only and 17 % for both combining lighting and mobile phone charging. It is as reported by referred article. L117-118

 [283] – should be “The number of residents"

“The number of the resident” change to “The number of residents”. L135.

[386] – should be feed instead of fit – but the acronym should be used here.

Fit-in-tariff change to Feed-in-tariff. L186

Figure 4 could still be improved further – wouldn’t the energy balance be done before the technoeconomic analysis? (the way they are presented in the figure makes it seem they are done in parallel).

Figure 4 change to show the flow of Energy balance performed before Technoeconomic analysis. L216.

It seems odd to have a category for 0-18 year olds for answering the survey – surely the age of the youngest participant can replace the 0.

“0-18 year olds” change to “18 years old and below”. L243.

The information provided in Figure 6 and the surrounding discussions are not a result of the research done in this paper. Rather, it is background information that was retrieved from other sources. This must be removed from the results section.

Figure 6 and surrounding discussion was removed. 

[1143] – explain what is meant by the energy consumption range?

“Energy balance analysis shows that PV efficiency and energy consumption range are 13.2 – 17.2 % and 72.1 – 97.1 %, respectively.” change to “Energy balance analysis shows that PV efficiency ranging between 13.2 – 17.2 % and PV energy consumption between 72.1 – 97.1 %”. “PV energy consumption” is the value in % of energy consumed (by the calculated load) from the PV energy generated. L411-412

In Figure 12 I think you mean difference instead of different. This should be changed and explain what it is in the figure caption.

Different change to difference and explanation added. L427-432