Analysis of Hybrid Grid-Connected Renewable Power Generation for Sustainable Electricity Supply in Sierra Leone
, Narayanan Krishnan 4, Alexey Mikhaylov 5 and Tomonobu Senjyu 1,*
Round 1
Reviewer 1 Report
please find attached some minor edits to be done
Comments for author File: 
Comments.pdf
Author Response
Thank you very much for taking your precious time to revise our manuscript, Hybrid Grid-Connected Renewable Power Generation for Sustainable Electricity Supply in Sierra Leone: Case Study Lungi Town. We appreciate the careful review and constructive suggestions. It is our belief that the manuscript is substantially improved after making the suggested edits
Author Response File: 
Author Response.docx
Reviewer 2 Report
This paper presents the techno-economic feasibility analysis of hybrid renewable energy sources to minimize loss of power supply probability and energy cost for Lungi Town. Please address the following concerns.
The font size in Figure 3 is too small to read.
Define the objective function of optimization in Section 3.5.
Typos in line 271: "When" should be "when."
The resolution of Figure 8 is too low.
The profiles used in the case study are unrealistic, as shown in Figures 9 and 10, because they are too ideally periodic. There would be cloudy days when solar generation is not enough. In figure 10, wind generation profiles in seven days are all the same.
Author Response
Thank you very for taking your precious time to revise our manuscript, Hybrid Grid-Connected Renewable Power Generation for Sustainable Electricity Supply in Sierra Leone: Case Study Lungi Town. We appreciate the careful review and constructive suggestions. It is our belief that the manuscript is substantially improved after making the suggested edits.
Author Response File: Author Response.pdf
Reviewer 3 Report
Manuscript Number: - sustainability-1314140-peer-review-v1
Submitted to: MDPI sustainability
Title: Hybrid Grid-Connected Renewable Power Generation for Sustainable Electricity Supply in Sierra Leone: Case Study Lungi Town
Report of Review
The paper aims at analyzing the techno-economic feasibility of hybrid renewable energy sources for sustainable electricity supply; case study of Lungi town. The study is a case study of a direct applicability, could authors enrich it and make it more general and profitable to the scientific community.
Critics:
Title is too long; make it more general.
Analysis of Hybrid Grid-Connected Renewable Power Generation for Sustainable Electricity Supply in Sierra Leone: Case Study Lungi Town.
Check thoroughly your English language; there are many syntax and grammatical errors in addition to several awkward sentences such as the beginning of the introduction.
Do not use “We”
The paper structure is not well organized. There is no coordination between sections and subsection
The Abstract should contain answers to the following questions: What problem was studied and why is it important? What methods were used? What are the important results? What conclusions can be drawn from the results? What is the novelty of the work and where does it go beyond previous efforts in the literature? Please include specific and quantitative results in your Abstract, while ensuring that it is suitable for a broad audience.
An updated and complete literature review should appear as part of the Introduction, while bearing in mind the work’s taking into account the scope and readership of the journal. The Introduction should make a compelling case for why the study is useful along with a clear statement of its novelty or originality by providing relevant information: What is already known in the open literature? What is missing (i.e., research gaps)? What needs to be done? Clear statements of the novelty of the work should also appear briefly in Conclusion section.
List of symbols is required.
I think Sierra Leone is not a keywords. Please revise for more significant keywords to be used.
Please correct here: Africa is blessed with abundant renewable 32 sources. These resources which are sustainable and environmentally friendly, and it is seen as a better may substitute to the traditional methods of power generation [6,7].
Please revise here: published a reasonable amount of literature on it
Revise the whole paragraph from 46 – 50.
Change he to they, and his to their , as there are more authors. Check thoroughly the whole paper about this concern.
How can only 50 MW power a capital city.
Check these words: karpower !!! ship stationed !!!
Remove long unnecessary information from 113 – 117
There are also many parts from section 2 which could be abbreviated, focusing only on the technical and economical aspects. Also there are many repeated sentences between section 1 and section 2.
Is Figure 1 representing the energy supply or requirement?
Make it concise an remove unnecessary information from 162 – 174
Figure 3 is useless.
Abbreviate Table 2 and table 2 lots of details.
Improve the quality of all illustrations.
There are many repeated sentences in section 2.2
Please check; There is conflicts between line 205 and figure 5 with the given direct normal irradiation of 1167kWh/m2,
There are many repeated sentences and basic information in section 3.1
Give references to all numbered equations. Check format of equation such as Eqt (1)
Check basic information in section 3.2
Check all units between line 250 and 253.
Give reference to figure 7
As there are many GA which one is used and give references.
Give references to equation (10)
Check all equations from (11) to (17) there some formatting errors
Reduce basic known information and generalities from line 301 to 354 in section 4.2
The targeted objectives, the search domain, the parameters and their conditioning and the objectives and constraints must be presented in their mathematical format and in tables.
The implementation of the optimization loop is not detailed and validated, so the consistency of results is not evident.
The intermediate optimization results must be shown
Pareto fronts must be revealed and discussed, and the same for the final optimum criteria which are opted for.
In figures 9 to 11 why the period of time is 160 hours. And why there are perfect periodicities, how that could be explained.
By referring to figure 13 and figure 14, the fundamental question whether the power obtained from PV, wind-turbine or battery corresponds to what size, units numbers etc... As I increase the number of panels or number of units of turbine the power developed will increase.
The DNI during days and months changes how this is considered
Same for the wind speed during days and months changes how this is considered
Table 7 does not show the number of units based on size and unit power for PV and wind-energy and the same for DG.
Conclusion should be concise. Focus on the findings and solutions feasibility and the perspectives.
Comments for author File: Comments.pdf
Author Response
Thank you very much for taking your precious time to reviewer our manuscript Hybrid Grid-Connected Renewable Power Generation for Sustainable Electricity Supply in Sierra Leone: Case Study Lungi Town. We appreciate the careful review and constructive suggestions. It is our belief that the manuscript is substantially improved after making the suggested edits. Unfortunately, the review came at a time when I am currently hospitalized. However, I have to do the work even though I am on my sickbed. I am in my home country Sierra Leone and the medical facility here is very poor. I am very much sorry for the delay. Thank you for your kind understanding.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
All concerns raised by this reviewer have been addressed properly.
Author Response
We would like to thank you very much for reviewing our manuscript. We appreciate the time and effort that you dedicated to providing feedback on our manuscript and we are grateful for the insightful comments on and valuable improvements to our paper. God bless you.
Author Response File: Author Response.docx
Reviewer 3 Report
Manuscript Number: - sustainability-1314140-peer-review-v2
Submitted to: MDPI sustainability
Title: Analysis of Hybrid Grid-Connected Renewable Power Generation for Sustainable Electricity Supply
Report of Review
There are still many queries unsatisfied. Authors should provide a rebuttable file to show the point by point answers and how answers and corrections are made in the new version of paper. This will facilitate to check all the amendments.
Critics:
- English language still requires polishing up.
- The paper structure is not well organized. There is no coordination between sections and subsection
- There is still a lot of detail and repetition in section 2, please focusing on the technical and economical aspects.
- Improve figs 3,6,8,9,10,12,13.
- Revise format of equation (1) not clear to the reader.
- Still many equations do not have references, such as equation (3)
- coefficient (3.7 * 10-3(1/oC ) should be 3.7x10-3 oC-1
- Give clearly the number of targeted objectives: one objective, bi-objective or more!!
- The search domain, the parameters and their conditioning and the objectives and constraints must be presented in their mathematical format and in tables.
- The implementation of the optimization loop is not detailed
- The optimum results could not be validated.
- In figures 9 to 11 why the period of time is 160 hours. why there is a perfect periodicity.
- By referring to figure 13 and figure 14, the fundamental question whether the power obtained from PV, wind-turbine or battery corresponds to what size, units numbers etc... As I increase the number of panels or number of units of turbine the power developed will increase.
- How the daily and monthly DNI changes are considered
- Same for the wind speed during days and months
- Table 7 does not show the number of units and unit power for PV and wind-energy and the same for DG.
- Conclusion focus on the solution feasibility and perspectives.
Author Response
We would like to thank you very much for reviewing our manuscript. We appreciate the time and effort that you dedicated to providing feedback on our manuscript and we are grateful for the insightful comments on and valuable improvements to our paper. God bless you.
Author Response File: Author Response.pdf
Round 3
Reviewer 3 Report
Manuscript Number: - sustainability-1314140-peer-review-v3
Submitted to: MDPI sustainability
Title: Analysis of Hybrid Grid-Connected Renewable Power Generation for Sustainable Electricity Supply
Report of Review
There are still many queries unsatisfied. Explanation provided should be also reflected in the paper text such. Many of my past queries were not incorporated properly in the paper.
Critics:
- Accolade in equation (1) please split equation; I do not understand what you want to say here.
- The optimum results could not be validated. I meant you must validate the whole optimization procedure before claiming hat results are good.
- The fundamental question whether the power obtained from PV, wind-turbine or battery corresponds to what size, units numbers etc... As I increase the number of panels or number of units of turbine the power developed will increase. This has to be well commented and discussed thoroughly as part of solution.
- How the daily and monthly DNI and wind speed changes are considered, I meant how their real variations are input and processed in real time during optimization.
Author Response
The authors would like to thank you very much for taking your precious time to revise our manuscript “Hybrid Grid-Connected Renewable Power Generation for Sustainable Electricity Supply in Sierra Leone: Case Study Lungi Town”. We appreciate the time and effort that you dedicated to providing feedback and we are grateful for the insightful comments on and valuable improvements to our paper. God bless you.
Sincerely yours,
Foday Conteh
Author Response File: Author Response.docx
