Optimal Sizing and Assessment of a Renewable Rich Standalone Hybrid Microgrid Considering Conventional Dispatch Methodologies

Round 1

Reviewer 1 Report

The paper shows standard optimization task od a wind/PV/batt/diesel generator based off-grid hybrid microgrid using commercial software HOMER. It is impossible to find any real contribution of the paper. Only a few case studies arepresented and no real novelty is present. It is also difficult to find the own authors' statement - what is the novelty of this paper?

Author Response

Reviewer#1, Comment#1: The paper shows standard optimization task od a wind/PV/batt/diesel generator based off-grid hybrid microgrid using commercial software HOMER. It is impossible to find any real contribution of the paper. Only a few case studies arepresented and no real novelty is present. It is also difficult to find the own authors' statement - what is the novelty of this paper?

 

Author Response: The authors would like to thank the respected reviewer for raising this critical point.

The reviewer has stated that the proposed work shows a standard optimization task using HOMER. The authors would like to clarify that, HOMER in this work has only been used as a primary software for estimating the optimum sizes and costs of the microgrid. MATLAB/Simulink platform has been used for further determination of the feasibility of the designed microgrids according to the power system responses. The core contribution, as well as the novelty of this research work, has been clearly mentioned by the authors in the last part of the introduction section (which is now presented in a separate section after the introduction (section 1.1).

 

According to the available literature, it is clear that microgrid designing and assessment using HOMER is common among many researchers. The concept of microgrid designing by implementing dispatch strategy-based control is relatively new. Analysis considering five different dispatch strategies is rare. Moreover, the available researches show that the respected researchers have confined themselves to microgrid designing and assessment only using HOMER. As we have found through our research, sometimes it can be seen that the HOMER predicted optimum sizes are different than the practically implementable sizes of the microgrid components. So, assessment through only HOMER is sometimes found not to be feasible. Keeping this demerit in mind we have implemented the HOMER predicted optimum results in a suitable Simulink microgrid model for feasibility analysis depending on the microgrid’s voltage and frequency responses. Moreover, as per the best knowledge of the authors, the proposed sites have not been taken for analysis previously by any researchers in the world.  All these clarifications/points prove the novelty as well as the contributions of this research.   

Author Action: New section (section 1.1) is introduced to emphasize the novelty and contribution of this research work.

Author Response File: Author Response.pdf

Reviewer 2 Report

This paper proposes, "Optimal Sizing and Assessment of a Renewable Rich 2
Standalone Hybrid Microgrid Considering Conventional Dis- 3
patch Methodologies”, the idea interesting. I would like to suggest few comments :

• Authors must include a section or subsection to show the core contribution of their proposed work.
• In The abstract what is HOMER, i would suggest make an another section for abbreviations specifications.
• Alignment of references are not properly addressed in the introduction section. Update the Introduction.
• A discussion on the possible limitations of their work may be included to enhance the quality and ethical fairness of their work.
• In the equation 4 what is the value of the coeffecients, i would suggest add another able to for all the parameters used during the implementation of this work.
• Equations 7 to 10 must be updated and how can the authors justify these equations .
• Invalid sentence, "One more thing should be kept in mind while calculation is that 294 in 3.667g of CO2 contains 1g of carbon", i would suggest to improve this sentence technically.
• Figures 4, 11 to 20 must be improved, the quality of these figures is not good.
•  Table IV shows the comparison for the proposed method, how is your method too much accurate, is it possible too much difference in the results. From 0.003375 to 1983487.984, authors need to see and check  the values again.
• In the abstract authors had mentioned about CO2 discharge of 3,375 kg/year, what will be the impacts on the environment, authors must mention about this also in there manuscript.
• Some typo and grammar mistakes must be removed as well.
• The current paper requires English proof read.

Author Response

Reviewer#2, Comment#1: This paper proposes, "Optimal Sizing and Assessment of a Renewable Rich 2 Standalone Hybrid Microgrid Considering Conventional Dis- 3 patch Methodologies”, the idea interesting. I would like to suggest few comments:

 

Author Response: The authors cordially thank the respected reviewer for this appreciation. The authors do believe that the suggestions of the respected reviewers will definitely enhance the quality and acceptability of the paper. The authors have also given their best to modify the manuscript as per the valuable suggestions of the reviewers.

Author Action: N/A

 

 

Reviewer#2, Comment#2: Authors must include a section or subsection to show the core contribution of their proposed work.

 

Author Response: The authors would like to thank the respected reviewer for the valuable comment.

The research gap in this domain of research, the core contribution of the proposed work, and the novelty of this proposed work are clearly stated in the last part of the introduction already.

 

Author Action: According to the comment of the respected reviewer, the authors have introduced two new subsections (1.1 Core Contributions of this Research work, 1.2 Paper Organization) to further emphasize the research gap, novelty, and core contribution of the work.

 

 

Reviewer#2, Comment#3: In The abstract what is HOMER, i would suggest make an another section for abbreviations specifications.

 

Author Response: The authors would like to express their cordial gratitude towards the respected reviewer for this suggestion.

HOMER is a professional microgrid designing and assessment software platform that simplifies the task of evaluating designs for both off-grid and grid-connected power systems. The full form of HOMER is Hybrid Optimization of Multiple Electric Renewables. 

 

Author Action: According to the suggestion of the respected reviewer, a list of abbreviations and it’s corresponding elaborative form is presented in a separate table in the last part of the manuscript (in appendix). And also, the full form of HOMER is mentioned in the abstract and in the main manuscript in the first place.

 

Reviewer#2, Comment#4: Alignment of references are not properly addressed in the introduction section. Update the Introduction.

 

Author Response: The authors would like to thank the respected reviewer for addressing this critical issue.

Author Action: According to the comment of the respected reviewer,  the introduction section has been reviewed again and the alignment error mentioned by the respected reviewer has now been eliminated.

 

 

Reviewer#2, Comment#5: A discussion on the possible limitations of their work may be included to enhance the quality and ethical fairness of their work.

 

Author Response: The authors are very much happy to thank the respected reviewer for this suggestion. A brief discussion on the limitations of the present work and possible future works is already presented in section 6 of the manuscript.

 

Author Action: According to the comment of the respected reviewer, the section has been rewritten to clarify the limitations and future research recommendations. The section has been renamed as “Limitations and Future Research Recommendations”.

 

 

Reviewer#2, Comment#6: In the equation 4 what is the value of the coeffecients, i would suggest add another able to for all the parameters used during the implementation of this work.

 

Author Response: The authors would like to thank the respected reviewer for the suggestion and for raising this critical issue.

The coefficients of equation 4 depend on the demand and amount of generation of the microgrid. The equations (1 to 19) shown in this work are mainly demonstrated to clarify the working procedure of HOMER. Practically HOMER utilizes HOMER optimizer (developed by HOMER) and it uses a deterministic algorithm which can be found from the HOMER data sheets available in-

https://www.homerenergy.com/products/pro/docs/latest/replacement_cost.html

https://www.homerenergy.com/products/pro/docs/latest/storage_outputs.html

***HOMER pro user manual (latest version 3.14) can be downloaded from: https://www.homerenergy.com/products/pro/docs/latest/index.html

HOMER names its optimization algorithm as Homer optimizer and within it, it considers all the constraints and coefficients. Please see:

https://www.homerenergy.com/products/pro/docs/latest/solving_problems_with_homer.html

Homer considers the constraints as discussed on pages 42,64,174,221 of the following pdf.

https://www.homerenergy.com/pdf/HOMER2_2.8_HelpManual.pdf

 

Author Action: According to the suggestion of the respected reviewer, the Nomenclature table is now introduced in the appendix section which contains the parameters used during the implementation of this work.

 

 

Reviewer#2, Comment#7: Equations 7 to 10 must be updated and how can the authors justify these equations.

 

Author Response: The authors would like to thank the respected reviewer for the detailed check. Using equations 7, 8, and 9, minimization of NPC, COE and carbon emission of the respective component (solar PV, wind turbine, diesel generator, battery, converter) is done. The weights are also used to emphasize on the significant component(s). According to the minimized costs, sizes and emissions based on different dispatch strategies, the suitable combination of component sizes is determined for the microgrid’s optimal operation. Equation 10 does the summary and finds the average result accordingly. (Arefin, S. S., Optimization Techniques of Islanded Hybrid Microgrid System. In Renewable Energy-Resources, Challenges and Applications, IntechOpen: 2020 at: https://www.intechopen.com/chapters/71506)

 

Author Action: According to the comment of the respected reviewer, the equations have been updated and the ‘dots’ are replaced with ‘multiplications’. Now the equations have become easier to understand.

 

 

Reviewer#2, Comment#8: Invalid sentence, "One more thing should be kept in mind while calculation is that 294 in 3.667g of CO2 contains 1g of carbon", i would suggest to improve this sentence technically.

 

Author Response: The authors would like to thank the respected reviewer for the suggestion. The authors do agree with the respected reviewer about the technical validity of the mentioned sentence and hence, the sentence has been rewritten.

 

Author Action: The sentence has been rewritten as “To estimate the carbon emission, the fact “3.667g of CO₂ contains 1g of carbon” needs to be taken into consideration.”

 

 

Reviewer#2, Comment#9: Figures 4, 11 to 20 must be improved, the quality of these figures is not good.

 

Author Response: The authors would like to thank the respected reviewer for the valuable comment. The authors agree with the reviewer and also are worried about the condition. The issue most probably raised because of the MS word platform. All of the figures are generated in very high quality using MS Visio, MS excel, and Simulink and have been rechecked. But the quality degrades whenever placed in MS word template and saved.

 

Author Action: The authors have already generated best quality figures and have replaced the current ones with the best quality figures in the word file. The original HD figures are also provided as supplementary files which can be used in final version production by the journal’s editing office if the paper is accepted for publication.

 

 

Reviewer#2, Comment#10: Table IV shows the comparison for the proposed method, how is your method too much accurate, is it possible too much difference in the results. From 0.003375 to 1983487.984, authors need to see and check  the values again.

 

Author Response: The authors are glad to thank the reviewer for asking about this critical issue.

The authors have rechecked the values and the secret of this much improvement lies in the implementation of Dispatch Strategy based control algorithm which has not been considered in the above mentioned literature. More over, the test sides considered in our work has more renewable resource than the test site considered in the mentioned literature

 

Author Action: In the article, the following part has been added in section 4.3

“The reason behind this much of improvement lies into the implementation of dispatch strategy based control and limiting the usage of diesel generator and keeping it only for backup power supply. The researchers in [51]  did not implement DS based control and which resulted in higher usage of diesel generator. On the other hand, conventional fossil fuel based power generation stations do use fossil fuels and thus produce a huge amount of GHG.” 

 

 

 

Reviewer#2, Comment#11: In the abstract authors had mentioned about CO2 discharge of 3,375 kg/year, what will be the impacts on the environment, authors must mention about this also in there manuscript.

 

Author Response: The authors would like to thank the respected reviewer for raising this concern.

Every person emits the equivalent of approximately two tons of carbon dioxide a year from the time food is produced to when the human body excretes it (https://www.sciencedaily.com/releases/2010/11/101102131108.htm). So, compared to this, the emission from our microgrid is not that much. Besides the amount of conventional Fossil fuel-based generation plants are much higher than our proposed microgrids as shown in Table V. The authors believe that the discussion about the impacts of this emission on the environment is beyond the current focus of this research work which is ‘dispatch strategy and power system response based microgrid designing’. And also, the impact is so significant on the environment as we all are aware of the global warming issues an all. So, this discussion will take the current research to another level.

Author Action: N/A

 

 

Reviewer#2, Comment#12: Some typo and grammar mistakes must be removed as well.

 

Author Response: The authors cordially thank the respected reviewer for this valuable concern and through check.

 

Author Action: The draft manuscript has been rechecked and reviewed again more than once by several authors to find and discard any typos and grammatical mistakes. Hope the manuscript is now more acceptable.

 

 

Reviewer#2, Comment#13: The current paper requires English proof read.

 

Author Response: The authors appreciate the valuable comment of the reviewer. The authors do agree that being nonnative speakers, there might be some mistakes in the manuscript.

 

Author Action: According to the suggestion of the respected reviewer, the draft manuscript has been rechecked, reviewed, and proofread by a native English speaker to eliminate the grammatical and other miscellaneous issues. 

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear Authors,

You will find attached a file with my considerations.
You should make several minor corrections to the text and same of the figures.

Pros: 
- Extensive analysis comparing five distinct load dispatch methodologies;
- Good explanation of the problem;
- Very Good simulation Results;

Cons:
- No experimental results;
- Figures 1, 3 and 4 need to be inproved, poor quality;
- No transitory simulations;
- Only comparison with one "Other HRES";

Comments for author File: Comments.pdf

Author Response

Reviewer#3, Comment#1: Dear Authors,

You will find attached a file with my considerations.
You should make several minor corrections to the text and same of the figures.

 

Author Response: The authors would like to express their heartiest gratitude towards the respected reviewer for the effort, time, and detailed checking. The authors have given their best to address all the comments raised by the respected reviewer and do corrections accordingly. The authors do believe that the corrections mentioned by the respected reviewer will make the manuscript more acceptable.

Author Action: N/A

 

Reviewer#3, Comment#2:

Pros: 
- Extensive analysis comparing five distinct load dispatch methodologies;

- Good explanation of the problem;

- Very Good simulation Results;

 

Author Response: The authors would like to thank the respected reviewer for the appreciation.

Author Action: N/A

 

Reviewer#3, Comment#3:

Cons:
- No experimental results;

- Figures 1, 3 and 4 need to be inproved, poor quality;

- No transitory simulations;

- Only comparison with one "Other HRES";

 

Author Response: The authors are grateful to the respected reviewer for the detailed review and concern.

-  The proposed microgrids have been designed for practical implementation. If we get funds and proper infrastructural support, we can practically set up the proposed microgrids. Then, it will operate commercially.

 

- The issue most probably raised because of the MS word platform. All of the figures have already been generated in very high quality using MS Visio, MS excel, and Simulink and have been rechecked. But the quality degrades whenever placed in MS word template and saved.

 

The authors have already generated the best quality figures and have replaced the current ones with the best quality figures in the word file. The original HD figures are also provided as supplementary files which can be used in final version production by the journal’s editing office if the paper is accepted for publication.

 

- This work mainly focuses on dispatch strategy based microgrid designing considering power system study in steady state domain and thus the authors have not taken transient study to be included in the research work to deliberately focus on the core objective and provide satisfactory outcomes.

 

- The research work not only compares with a single ‘other work’ but also shows a comparison between the proposed microgrid and traditional fossil fuel-based power station as shown in Table V

 

Author Action: N/A

 

Reviewer#3, Comments from pdf attachment:

 

 

Reviewer#3, Comment#1: Please read the comments made throughout the document.

 

Author Response: The authors would like to thank the reviewer for the great effort. The authors have given their best in addressing all the concerns raised by the respected reviewer and they believe that the corrections and modifications suggested by the reviewer will definitely improve the quality of the work and it’s acceptability.

 

Author Action: N/A

 

Reviewer#3, Comment#2: I believe the correct word should be emission and not emersion. You used the word emersion all over the text. Please check this.

 

Author Response: The authors would like to thank the respected reviewer for this detailed check.

The authors also believe that ‘emission’ is the most popular word in this case. The authors intentionally used a synonym of ‘emission’ which is ‘emersion’. The word ‘emission’ has been extensively used in many research articles which results in a more plagiarism percentile. That’s why the authors chose ‘emersion’.

 

Author Action: Now that the respected reviewer has raised his concern about this issue and the authors also believe this might create confusion, the word ‘emersion’ is now replaced with ‘release’ all over the text. Hope the respected reviewer finds it appropriate. 

 

Reviewer#3, Comment#3: Emissions?

 

Author Response: The authors would like to thank the respected reviewer for this detailed review. The comment is about Page 3, Line 147. Reviewer#3, comment#2 contains a detailed explanation.

Author Action: The word ‘emersion’ is now replaced with ‘release’.

 

Reviewer#3, Comment#4: Improve this figure  

 

Author Response: The authors would like to appreciate the effort the respected reviewer has given.

The comment is about Fig 1. The explanation behind poor quality figures is already given in reviewer#3, comment#3 (general comments).

 

Author Action: The figure has been improved. HD quality figure is also provided as a supplementary file. Which can be used for final version production by the production team of the journal if accepted for publication. 

 

Reviewer#3, Comment#5: Could you elaborate on this? Explain the figure  

 

Author Response: The authors would like to thank the respected reviewer for raising this important concern. The comment has been introduced about Figure 2.

 

Author Action: The following lines have been introduced before figure 2 as an explanation to the figure. “Whenever the renewable resource is high, LF and CC have higher impact on the microgrid. The need for backup DG is least in LF and, in CC, it is the highest. On the contrary, when the renewable sources are comparatively lower, the impact of CD and GO strategy is the lowest on the microgrid. HOMER PS strategy, on the other hand, stays in a medium position in respect to renewable resource utilization and backup generation implementation.”

 

Reviewer#3, Comment#6: what are this dots? Multiplçication? a.LCOE (I am confused)

 

Author Response: The authors would like to thank the respected reviewer for questioning about this critical issue. The question has been asked about equations 7,8,9.

In the equations, a, b, c, d are corresponding capacities of various microgrid components, and f₁, f₂, f₃ are weights to mean the corresponding component’s significance. NPC refers to the corresponding equipment’s net present cost, LCOE refers to the corresponding equipment’s levelized cost of energy, e.CO₂ and GHG refer to the quantity of carbon-di-oxide and greenhouse gas release by the hybrid microgrid, respectively. So, yes in the equations 7, 8 the dots are multiplications (eg. a.LCOE) (details can be found at https://www.intechopen.com/chapters/71506).

In equation 9, the ‘e.CO2’ refers to carbon di oxide emission which can also be found in equation 13. The authors do agree with the respected reviewer that, this might create confusion. So, the following corrections are introduced.

 

Author Action: In equations 7,8, the dots (.) have been replaced with the multiplication signs ().  In equation 9 dot (.) has been deleted. eCO₂ refers to the emission of Carbon di oxide.

 

Reviewer#3, Comment#7: should be a dot here too?

 

Author Response: The authors would like to thank the respected reviewer for questioning about this critical issue. The question has been asked about equation 10. Yes, here also (like equation s 7-9), f₁, f₂, f₃ are weights to mean the corresponding component’s significance. So they need to be multiplied. According to the respected reviewer’s suggestion, to avoid confusion, the following correction has been made.

 

Author Action: In equation 10, the dots (.) have been replaced with multiplication signs (). 

 

Reviewer#3, Comment#8: emission

 

Author Response: The authors would like to thank the respected reviewer for this detailed review. The comment is about Page 7, Line 291. Reviewer#3, comment#2 contains a detailed explanation.

Author Action: The word ‘emersion’ is now replaced with ‘release’.

 

Reviewer#3, Comment#9: Improve figure 3

 

Author Response: The authors would like to thank the respected reviewer for the review. The improved quality figure has been now used and has also been submitted as supplementary files.

 

Author Action: The figure has been updated and also been submitted as supplementary files.

 

Reviewer#3, Comment#10: Why not in USD like the others? please standardize

 

Author Response: The authors would like to thank the reviewer for this detailed review. The comment is about Page 9, line 351. $ has been also used as USD. We agree with the respected reviewer about this issue that the use of both ‘$’ and ‘USD’ may confuse the reader.

 

Author Action: All the ‘$’ are replaced with ‘USD’.

 

Reviewer#3, Comment#11: emission

 

Author Response: The authors would like to thank the respected reviewer for this detailed review. The comment is about Page 9, Line 354. Reviewer#3, comment#2 contains a detailed explanation.

 

Author Action: The word ‘emersion’ is now replaced with ‘release’.

 

Reviewer#3, Comment#12: ??? too vague  

 

Author Response: The authors would like to thank the respected reviewer for the review. This comment is about page 9, line 367. The line has been changed to a simpler structure.

 

Author Action: The new lines are now “From this study it has been observed that the optimum sizes of the system components obtained from the HOMER study for an area, when implemented in Simulink microgrid model, do not give a possible, steady, and reliable power system output always. For this reason, the HOMER anticipated optimal sizes in Table II have been calibrated and reported in Table III, on basis of the ‘trial and error’ method for a real-time power system study in Simulink. The changes have been marked in table III.”

 

Reviewer#3, Comment#13: speed is given in m/s, m/s^2 is acceleration  

 

Author Response: The authors would like to thank the respected reviewer for this detailed check and for finding this critical problem. This comment is about the flow chart in figure 4. This has been a typing mistake by the authors. The mentioned problem has been corrected.

 

Author Action: The flow chart has been corrected. Now m/s has been used.

 

Reviewer#3, Comment#14: Place the elements in Table II and III in the same order as in Table I. In the same sequence

 

Author Response: The authors would like to thank the respected reviewer for this detailed check.

 

Author Action: The problem has now been corrected and Table II and III has the same order as Table I.

 

Reviewer#3, Comment#15: Suggestion: Maybe putting figures 7 and 9 (8 and 10 too) side by side help the comparison between Homer and Simulink

 

Author Response: The authors would like to thank the respected reviewer for this wonderful suggestion. The authors also agree with this and have taken the necessary action.

 

Author Action: Figures 7 and 9 are now placed side by side and are now figure 7, and figures 8 and 10 are now placed side by side, and are leveled as figure 8.

 

Reviewer#3, Comment#16: between 400 V and ????  

 

Author Response: The authors would like to thank the respected reviewer for this detailed check. This comment is about page 14, line 506. The authors do agree that ‘between’ should not be a perfect word choice here.

Author Action: Now, ‘between’ has been replaced with ‘within’.

 

Reviewer#3, Comment#17: steady?

 

Author Response: The authors would like to thank the respected reviewer for this detailed check. This comment is about page 14, line 511. A ‘is’ before steady was mistakenly placed.

 

Author Action: Corrected. ‘is’ is removed.

 

Reviewer#3, Comment#18: ???

 

Author Response: The authors would like to thank the respected reviewer for this detailed check. This comment is about page 15, line 525. It should be ‘is staying’

 

Author Action: Corrected. ‘stays’ is corrected with ‘is staying’.

 

Reviewer#3, Comment#19: Stays at?

 

Author Response: The authors would like to thank the respected reviewer for this detailed check. This comment is about page 15, line 527.

 

Author Action: Corrected with ‘stays at’.

 

Reviewer#3, Comment#20: e ??????

 

Author Response: The authors would like to thank the respected reviewer for this detailed check. This comment is about page 15, line 551. The ‘e’ has been mistakenly placed.

 

Author Action: ‘e’ has been deleted.

 

Reviewer#3, Comment#21: ???

 

Author Response: The authors would like to thank the respected reviewer for this detailed check. This comment is about ‘between 1000 V’ in page 15, line 551.

Author Action: ‘between’ has been replaced with ‘at’.

 

Reviewer#3, Comment#22: about?

 

Author Response: The authors would like to thank the respected reviewer for this detailed check. This comment is about ‘between 400 V’ in page 15, line 557.

 

Author Action: ‘between’ has been replaced with ‘at’

 

Reviewer#3, Comment#23: In simulations 11 to 20, was any load step applied? Have any transients been tested?  

 

Author Response: The authors would like to thank the respected reviewer for pointing out this critical issue.

 

No load step has been applied and no transients have been tested either in this research work. Our main concern in this research work was to design and evaluate a microgrid based on dispatch strategies and power system responses in the steady state domain. So, the authors wanted to stay focused on the core contribution.

 

Author Action: N/A.

 

Reviewer#3, Comment#24: delete  

 

Author Response: The authors would like to thank the respected reviewer for this detailed check. This comment is about page 19, line 581.

 

Author Action: ‘the’ was mistakenly placed. Now deleted.

 

Reviewer#3, Comment#25: emersion

 

Author Response: The authors would like to thank the respected reviewer for this detailed review. The comment is about Page 19, Line 606. Reviewer#3, comment#2 contains the detailed explanation.

 

Author Action: The word ‘emersion’ is now replaced with ‘release’.

 

Reviewer#3, Comment#26: emersion

 

Author Response: The authors would like to thank the respected reviewer for this detailed review. The comment is about Page 20, Line 609. Reviewer#3, comment#2 contains the detailed explanation.

 

Author Action: The word ‘emersion’ is now replaced with ‘release’.  

 

Reviewer#3, Comment#27: Why not GO? Maybe you should justify why GO is worst than LF.  

 

Author Response: The authors would like to thank the respected reviewer for raising a question about this critical issue. The comment is about page 20, lines 616-619. The justification for GO strategy is now added.

 

Author Action: The following explanation has been added in section 4.4, determining the best and worst dispatch approaches.

“GO on the other hand needs the highest PV and converter sizes. NPC and COE in GO strategy are higher than LF and lower than other strategies. In GO, the lowest sized DG of 1 kW is used, which results in the lowest carbon emission in this strategy. For Kushighat, GO offers a worse frequency response than LF and for Rajendro bazar, GO is better than LF. Considering costing, sizing, emissions and power system responses, overall, LF performs better than GO.”

 

Reviewer#3, Comment#28: Emersion

 

Author Response: The authors would like to thank the respected reviewer for this detailed review. The comment is about Page 20, Line 616-654. Reviewer#3, comment#2 contains the detailed explanation.

 

Author Action: The word ‘emersion’ is now replaced with ‘release’.

 

Reviewer#3, Comment#29: Emersion

 

Author Response: The authors would like to thank the respected reviewer for this detailed review. The comment is about Page 20, Line 616-658. Reviewer#3, comment#2 contains the detailed explanation.

 

Author Action: The word ‘emersion’ is now replaced with ‘release’.  

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The improved version is more readable but still this version didn't convince me about the extent of contribution and novelty. The approach is standard , the use of most common software tools and obvious results doesn't guarantee inclusion in a journal with a quite high reputation.

Author Response

Reviewer#1, Comment#1: The improved version is more readable but still this version didn't convince me about the extent of contribution and novelty.

Author Response: The authors would like to thank the respected reviewer for the appreciation and comment.

The paper has gone through a lot of modifications according to the comments of the respected reviewers. The core objective of this research was to fill up the research gap of not properly utilizing the dispatch strategy based microgrid designing and assessment on basis of power system responses and techno-economic analysis for the two proposed locations implementing a -solar PV-wind turbine-battery-diesel generator based islanded hybrid microgrid for the proposed Kushighat and Rajendro Bazar microgrids along with the already available distribution system. In this work-

• HOMER optimization is utilized for the evaluation and design of the proposed Integrated Hybrid Microgrid System (IHMS), which will guarantee the least CO₂ production, Cost of Energy (COE), and Net Present Cost (NPC) for the planned areas for different dispatch methodologies;
• Microgrids’ response (voltage and frequency) is evaluated in Simulink to guarantee achievable, effective, and reliable performance;
• Five alternative dispatch techniques have been considered and conducted a brief comparative analysis in this study and on the basis their performances in terms of least cost, GHG release and power system responses the worst and best dispatch approaches for the proposed microgrids have been declared.
• The authors synchronized the optimal sizing and techno-economic analysis with the power system performances of the designed islanded microgrid which is significant, new and novel till date.

The authors would like to strongly claim that to the best knowledge of the authors, such study has not been done by any authors till now. This do clarify the novelty section.

The contribution of this research is that, this research does fill the research gap in this area of research. This research work has been done considering accurate load demands, costings and meteorological profiles. This work has also simulated the feasibility and stability analysis in MATLAB Simulink platform. The results obtained from this research can be implemented for real life microgrid implementation which would have impact on solving the energy scarcity related problems in third world countries like Bangladesh. 

The application of the proposed research covers a very wide range of area specially covering microgrid application in decentralized or isolated regions as mentioned in the last part of the manuscript. The research work can be successfully implemented in isolated mobile BTS or market or in agricultural applications. More over, the analysis is applicable not only for the proposed locations but also for any locations in the world with similar meteorological condition and load profile. So, the authors do believe that the contribution of this research work is up to the mark to be considered to be included in a highly reputed journal like Sustainability.

 

Reviewer#1, Comment#2: The approach is standard, the use of most common software tools and obvious results doesn't guarantee inclusion in a journal with a quite high reputation.

 

Author Response: The authors would like to thank the respected reviewer for the well thought comment.

The authors do agree with the respected reviewer that, the designed and simulated research work has been conducted by using deterministic optimization tool called HOMER and MATLAB Simulink. But the application of these common simulation tools does not mean that the results will be obvious. In this work we have proposed two microgrid designs for the optimum operation. The optimum costs, emissions and sizes for different locations and for different load profiles analyzed in HOMER domain is definitely different and are not obvious depending on different dispatch controls, meteorological and load profile conditions.  For any change in the parameters generate different optimum conditions. Moreover, the results are not directly taken from HOMER. The values from HOMER Pro simulations are taken and were simulated enormous times in the suitable microgrid. If the results were so obvious, then there would have been no need for extra simulations. Moreover, the achieved optimal sizes from HOMER of each module have been tuned and readjusted in MATLAB Simulink platform to make the system stable and ensure the feasible microgrid operation.

Sustainability is a very well reputed journal with a very high impact factor. The authors do believe that the work has now been extensively modified according to the respected reviewer(s) well thought comments and suggestions and have become worthy to be considered to be a part of this highly reputed journal.

Author Response File: Author Response.pdf

Reviewer 2 Report

Greetings

Dear Authors, The comments had been addressed, I would still suggest to add a table of parameters. The comment 6 in the first revision has not been taken into consideration. 

Good Luck 

Author Response

Reviewer#2, Comment#1: Greetings

Dear Authors, The comments had been addressed, I would still suggest to add a table of parameters. The comment 6 in the first revision has not been taken into consideration. 

Good Luck 

Author Response: The authors would like to thank the respected reviewer for the comment and appreciation and also do want to express their sincere apology as the author’s response for previous comment 6 did not satisfy the reviewer's concern though the author tried their best to address all the comments previously given by the reviewer.

The authors would like to express their gratitude for the suggestion of adding a table. The comment had been taken previously into consideration and a table was added in the appendix section.

Nomenclature

 

Ngen	number of generator units
aj, bj, cj	fuel cost coefficients of the jth generator
Fj(Pj)	cost function of fuel of the jth generator in USD/hour
Pj	power output of the jth generator in MW
Ploss	net system loss
Pdemand	net consumer demand
Bij, B0i, B00	coefficients of loss
	electricity generated from the ith generator
	lowest generation range,
	highest source capacity
	storage power
a, b, c, d	corresponding capacities of various microgrid components
f1, f2, f3	weights to mean the corresponding component’s significance
Cannual	yearly net cost
Lprimary	net primary demand
Egs	net energy brought by the traditional grid each year
Ld	net deferrable demand
i	rate of interest (annualized)
Cannual	annual net cost
Tproject	longevity of the project
CRF (.)	capital recovery factor
eCO2	amount of CO2 gas
mfuel	amount of fuel in Liter
FHV	Fuel heating value in MJ/L
CEFfuel	carbon emission factor in ton carbon/TJ
Xc	oxidized carbon fraction
fnadir	frequency nadir
RoCoF	Rate of Change of Frequency
H	microgrid’s inertia
D	load damping factor
Δf (t)	frequency deviation
PM	microgrids power imbalance
ΔPSj (t)	power differences of generation unit i
ΔPGi (t)	power differences of battery j

 

The comment 6 in previous revision was “In the equation 4 what is the value of the coefficients, i would suggest add another able to for all the parameters used during the implementation of this work”

The comment was taken into full consideration and was replied with author response. May be the response did not satisfy the respected reviewer. The core objective of this research work was to design and evaluate two microgrids for the proposed locations considering dispatch strategy and power system responses. The equations in the manuscript are mentioned with an intention of properly mathematically modeling the optimization problem. HOMER optimizer does provide us the flexibility of choosing the appropriate values of the coefficients which are needed for the optimal operation of the microgrids. Thus, the values of the coefficients while using HOMER Pro are already predefined and it is close access due to the copyright of HOMER. Thus, the authors do believe the mention of coefficients values in another table would be redundant as the optimization is conducted using HOMER. Hope the response satisfies our respected reviewer.

Author Response File: Author Response.pdf