Optimizing Sustainability Offshore Hybrid Tidal-Wind Energy Storage Systems for an Off-Grid Coastal City in South Africa
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsAuthors do a nice work. All the data are very solid. The current work is very meaningful. If authors can give some forecast results of offshore wind energy, that would be much better. Also, potential social influence of current results should be mentioned.
Author Response
Reviewer 1 Comments:
Thank you for your valuable feedback. We have revised the Title, Abstract, and Keywords to more effectively emphasize the contribution of our research to sustainability. The new title is: "Optimizing Sustainability in Offshore Hybrid Tidal-Wind Energy Storage Systems for an Off-Grid Coastal City in South Africa." This revision underscores the focus on sustainable energy solutions.
In the Abstract, we have explicitly highlighted the sustainability benefits of our findings, particularly in advancing renewable energy integration and reducing greenhouse gas emissions. Additionally, we have incorporated relevant keywords such as "sustainable energy systems," "HOMER Pro optimization," and "renewable energy sustainability" to better align the manuscript with the journal's focus on sustainability. We have also included an analysis of offshore wind resources to provide a comprehensive forecast and reinforce the potential of offshore hybrid systems. These changes aim to better showcase the environmental and societal impact of our research.
Reviewer 2 Report
Comments and Suggestions for Authors
The introduction should simply focus on research, results, and not perfect of previous works. It needs to be improved
The proposed method lacks mathematical modeling.
The numerical method should be discussed and verified, is the numerical method used in this paper verified, or the numerical method used in this paper was verified by other literatures.
The tables have been taken directly from HOMER without any modification, which is not acceptable for a research article.
The results are not verified, they need to be improved in their entirety.
Author Response
Reviewer 2 Comments:
Thank you for your valuable feedback. We have revised the Introduction section to place greater emphasis on the research objectives, methodologies, and key findings of our study. Instead of critiquing previous works, we now focus on how our research addresses existing gaps and contributes to the field. This refinement provides a clearer context for the significance and relevance of our study.
Comment 2: The proposed method lacks mathematical modeling.
Response: We appreciate your comment regarding the need for mathematical modeling. In response, we have included a detailed mathematical model of the proposed hybrid energy system in Section 3 of the revised manuscript. This model outlines the power conversion processes and energy storage dynamics, incorporating equations for both tidal and wind energy generation, as well as the energy storage system. These additions aim to provide a robust theoretical foundation for our proposed method, thereby enhancing the technical rigor of the study.
Comment 3: The numerical method should be discussed and verified. Is the numerical method used in this paper verified, or was it verified in other literature?
Response: We acknowledge the importance of verifying the numerical method. In this study, we relied on HOMER Pro’s simulation results, which are derived from the input data. To ensure robustness and reliability, we have compared our simulation outputs with established case studies from the literature and conducted sensitivity analyses. This verification process supports the accuracy and applicability of the numerical methods used in our research.
Comment 4: The tables have been taken directly from HOMER without any modification, which is not acceptable for a research article.
Response: Thank you for pointing this out. We have restructured the tables to present the data more clearly and accurately, including necessary modifications to improve their clarity and relevance. Additionally, we have provided detailed explanations to better interpret the data. These changes ensure that the tables conform to the standards expected in a research article.
Figures 2, 5, and 11: These figures were originally part of my master’s thesis” MODELLING AND SIMULATION OF TIDAL ENERGY GENERATION SYSTEM”, which has been properly cited. We have replaced the previous images with new, original maps created using Google Maps, with appropriate attributions provided.
Tables 5, 6, and 7: The data for these tables were derived from HOMER Pro libraries, specifically related to price parameters for various macrogrid components. We have cited the most recent relevant publications in these cases where necessary.
Comment: Highlight revisions for easy identification.
Reviewer 3 Report
Comments and Suggestions for AuthorsThis paper proposes a combined power generation system that harnesses both offshore wind and tidal current energy. The complementary characteristics of offshore wind and tidal current energy are analyzed, highlighting the predictability of tidal energy and the variability of wind energy. This paper has certain theoretical research significance, but there are many problems, which must be solved before it is considered for publication.
1. It is important to ensure that all tables and figures comply with the journal's formatting guidelines regarding font size, caption styles, and spacing. This will guarantee their presentation in a clear and professional way.
2. The four tidal turbines in line 17 of the abstract section should be changed to five to ensure consistency with the main text.
3. Line 155 could read that The practical application of wind energy is primarily the conversion of wind energy into other forms of energy, a process usually achieved through wind turbines, which capture and convert the energy of wind currents.
4. Row 165 could be replaced by transferring mechanical energy through the drive train to the generator, which converts it into electrical energy.
5. Figure 2 could be embellished by removing the boxes from the icons and the scales from the upper and lower axes.
6. Put the three different values for rotor diameter in Table 1 in one row and change the hub height as well.
7. Figure 3 could be further embellished, e.g., the tables describing the various components could have their borders removed, with attention paid to the cursor's position in the screenshot.
8. There is an error in interpreting the formula in (3).
9. Figure 1 on line 331 should be figure 7.
10. There is repetitive content in lines 339 - 341. Please condense this part.
11. The parameters of the wind turbine described in 6.1 are inconsistent with those in Table 5; the parameters of the tidal turbine described in 6.2 are inconsistent with those in Table 6, and the parameters of the battery described in 6.3 are inconsistent with those in Table 7.
12. Figures 16 and 17 are inconsistent with the description and do not reflect wind speeds over one year.
13. In line 561, Figure 14 does not illustrate how HOMER software evaluates and optimizes various configurations of turbines and generators to manage demand fluctuations throughout the year.
Author Response
Dear Reviewer, Thank you so much for important remarks:
Thank you for your suggestion. We have carefully reviewed all tables and figures in the manuscript and updated them to comply with the journal's formatting guidelines. Font sizes, caption styles, and spacing have been adjusted to ensure a clear and professional presentation.
Comment 2: The four tidal turbines mentioned in line 17 of the abstract should be changed to five to ensure consistency with the main text.
Response: We appreciate your attention to detail. We have corrected the abstract to state "five tidal turbines," ensuring consistency with the main text.
Comment 3: Line 155 could read, "The practical application of wind energy is primarily the conversion of wind energy into other forms of energy, a process usually achieved through wind turbines, which capture and convert the energy of wind currents."
Response: Thank you for the suggestion. We have revised Line 155 as recommended to improve clarity and accuracy.
Comment 4: Line 165 could be replaced by "transferring mechanical energy through the drive train to the generator, which converts it into electrical energy."
Response: We have updated Line 165 as suggested to provide a more precise description of the energy conversion process.
Comment 5: Figure 2 could be improved by removing the boxes from the icons and the scales from the upper and lower axes.
Response: We have revised Figure 2 as recommended by removing the boxes around the icons and eliminating the scales from the axes to enhance the figure's clarity and visual appeal.
Comment 6: Put the three different values for rotor diameter in Table 1 in one row and change the hub height as well.
Response: We have modified Table 1 as suggested by consolidating the rotor diameter values into a single row and updating the hub height values for consistency and clarity.
Comment 7: Figure 3 could be further embellished, for example, by removing the borders around the tables describing the various components, with attention paid to the cursor's position in the screenshot.
Response: We have enhanced Figure 3 by removing the borders around the tables and ensuring no cursors are visible in the screenshot. These modifications improve the overall presentation of the figure.
Comment 8: There is an error in interpreting the formula in (3).
Response: We have reviewed and corrected the interpretation of formula (3) to accurately reflect its intended meaning. Thank you for pointing this out.
Comment 9: Figure 1 on line 331 should be labeled as Figure 7.
Response: We have corrected the labeling of Figure 1 to Figure 7 as suggested. This change ensures proper alignment with the figure numbering sequence in the manuscript.
Comment 10: There is repetitive content in lines 339–341. Please condense this part.
Response: We have condensed lines 339–341 to eliminate redundancy and improve the flow of the text. The revised content now provides the necessary information more succinctly.
Comment 11: The parameters of the wind turbine described in Section 6.1 are inconsistent with those in Table 5; the parameters of the tidal turbine described in Section 6.2 are inconsistent with those in Table 6, and the parameters of the battery described in Section 6.3 are inconsistent with those in Table 7.
Response: We have reviewed and corrected the inconsistencies between the descriptions in Sections 6.1, 6.2, and 6.3 and the corresponding tables (Tables 5, 6, and 7). All parameter values are now consistent throughout the manuscript.
Comment 12: Figures 16 and 17 are inconsistent with the description and do not reflect wind speeds over one year.
Response: We have revised Figures 16 and 17 to accurately represent wind speeds over one year, as described in the manuscript. This correction aligns the figures with the text and provides a clearer representation of the data.
Comment 13: In line 561, Figure 14 does not illustrate how HOMER software evaluates and optimizes various configurations of turbines and generators to manage demand fluctuations throughout the year.
Response: We have revised the description of Figure 14 to clearly illustrate how HOMER software evaluates and optimizes different configurations. We have also updated the figure caption to provide a more detailed explanation of how the software manages demand fluctuations over the year.
Thank you for your time and valuable input.
Best regards,
Ladislas Mutunda Kangaji
Round 2
Reviewer 2 Report
Comments and Suggestions for Authors The document has been improved, but needs other changes. Figures need to be significantly improved or changed 2,3,6,9,12,14,15,17,18,19,20,22,25,30 The beginning of the description of figure 18 is in lowercase, review the entire document. Usually there are 5 class words, not phrases. Review the units, use k and K
Author Response
Comment 1: The document has been improved, but needs other changes. Figures need to be significantly improved or changed (2, 3, 6, 9, 12, 14, 15, 17, 18, 19, 20, 22, 25, 30).
Response: Thank you for pointing this out. We have significantly improved the quality of Figures 2, 3, 6, 9, 12, 14, 15, 17, 18, 19, 20, 22, 25, and 30 by enhancing the resolution, ensuring consistency in formatting, and updating the visual elements to make the figures clearer and more informative. We believe these changes address your concerns and improve the overall presentation of the data.
Comment 2: The beginning of the description of figure 18 is in lowercase, review the entire document.
Response: We have corrected the figure description for Figure 18, ensuring it starts with an uppercase letter. Additionally, we have thoroughly reviewed the entire document to ensure that all figure descriptions are consistent and formatted correctly.
Comment 3: Usually there are 5 class words, not phrases.
Response: We appreciate this observation. We have revised the content accordingly, ensuring that we use the standard five class words rather than phrases where applicable. This adjustment has been made to maintain clarity and consistency throughout the manuscript.
Comment 4: Review the units, use k and K.
Response: We have reviewed the usage of units throughout the manuscript, ensuring that "k" is used correctly for kilo (e.g., kW for kilowatts) and "K" for Kelvin where appropriate. All inconsistencies have been corrected to adhere to standard conventions.
We hope that these changes address all your concerns. Thank you once again for your valuable feedback, which has helped us improve the quality of our manuscript.
Reviewer 3 Report
Comments and Suggestions for AuthorsI have no other questions. Thank you
Author Response
Thank you for your time and effort in reviewing our manuscript. We appreciate your feedback and are glad that you are satisfied with the current version.
