Innovations in Wind Turbine Blade Engineering: Exploring Materials, Sustainability, and Market Dynamics

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript is problematic in two ways: some of the facts are not accurate and some of the text and facts are very redundant.

Regarding accuracy, facts such as stating that carbon fiber are interesting for wind turbine blades because of their strength to weight ratio is not correct. It is because of their stiffness to weight ratio. Carbon fibers also don’t bring better recyclability to wind turbine blades. Another example of inaccuracy can be found in the section dedicated to recycling, where the re-wind network project is mentioned in the section on chemical recycling. This network is not performing chemical recycling of blades, but repurposing of blades. Repurposing is not mentioned as an end-of-life option. This is an indication that the authors probably have not checked the reference. Finally, a number of places lack references, such as from line 1244 “With an increasing focus on sustainability, new standards are also being developed to address the environmental impact […].” There are no reference given for these new standards after that sentence and the reference given at the end of the paragraph line 1251, reference 67 is about offshore wind turbines and mainly about metals and monopile design.

Regarding redundancies, below is an example on the words “carbon fiber”. Carbon fiber is mentioned 16 times throughout the manuscript. In 11 cases the sentence summarizes the properties of carbon fiber. This is not needed, just one time would be enough. In addition, the sentence always mentions the positive side of carbon fibres, but not the negative ones.

1.        From Line 82: “Carbon fiber composites offer unparalleled strength-to-weight ratios and fatigue resistance, enabling the design of longer, more durable blades that enhance the energy capture of wind turbines”

2.        From line 123: “[…] major innovations such as Carbon Fiber Reinforced Polymer (CFRP) for enhanced strength-to-weight ratios, to recent advances in bio-based composites and nano-enhanced materials.”

3.        From line 137: “the use of carbon fiber composites, which offer an exceptional strength-to-weight ratio, superior stiffness, and increased fatigue resistance, making them ideal for large-scale turbine applications

4.        From line 141: “Carbon fiber's lightweight properties allow for the design of longer blades that can capture more wind energy without compromising structural integrity.”

5.        From line 165: “Highlighting key parameters such as density, tensile strength, and flexibility, this table elucidates the differences between traditional materials like metals and fiberglass, and more advanced composites like carbon fiber and bio-based al- 167 ternatives.

6.        From line 183: Materials like carbon fiber composites and bio-based composites not only enhance the physical properties of blades but also extend their operational life and reduce maintenance costs, fundamentally changing the economics of wind energy [16].

7.        From line 187: Carbon fiber's high stiffness and fatigue resistance allow for the construction of longer blades that are resilient under fluctuating and harsh wind conditions.

8.        From line 192: Moreover, the reduced weight of carbon fiber blades decreases the load on turbine bearings and structures, thereby minimizing wear and tear and enhancing the lifespan of the turbine's mechanical components [17].

9.        From line 239: Carbon fiber composites represent a significant advancement, delivering high energy efficiency due to their superior strength-to-weight ratio and excellent durability which reduces the frequency and costs of maintenance.

10.   From line 591: In contrast, carbon fiber composites provide an improved profile with excellent strength and better recyclability, yet they still carry a moderate carbon footprint.

11.   From line 1118: Innovations in materials such as carbon fiber composites used in projects like the Gansu Wind Farm offer improved durability and performance under harsh conditions.

Finally, an example combining both inaccuracy and redundancy, the strength to ratio of carbon fiber, which is not the reason why carbon fibers are used in blades is mentioned in 4 occasions as:

1.        unparalleled strength-to-weight ratios

2.        enhanced strength-to-weight ratios

3.        exceptional strength-to-weight ratio

4.        superior strength-to-weight ratio

Author Response

Response to Reviewer 1:

Dear Reviewer 1,

Thank you very much for your detailed and insightful comments on our manuscript. Your feedback has been invaluable in guiding the revisions we have made to enhance the accuracy and clarity of our work.

Revisions Based on Your Comments:

1. We have corrected the descriptions related to carbon fiber, particularly changing mentions of "strength-to-weight ratio" to "stiffness-to-weight ratio," which is more relevant to the material’s application in wind turbine blades.
2. We have clarified the sections discussing the end-of-life options for turbine blades, specifically correcting the information about the Re-Wind network project to accurately represent its focus on repurposing rather than chemical recycling.
3. We have thoroughly reviewed the manuscript to ensure that all claims, especially those regarding new standards and environmental impacts, are now supported by up-to-date and relevant references.
4. We have addressed the issue of redundancy by carefully revising the text to minimize repetitive mentions of carbon fiber properties, ensuring that each mention adds value and context to the discussion. We have also strived to provide a balanced view by including both positive and negative aspects of using carbon fibers in turbine blades.

To make it easier for you to review the changes, we have highlighted all revisions in green within the manuscript. This should facilitate quick identification of the modifications we have made in response to your comments.

We are deeply appreciative of the time and effort you have taken to review our manuscript. Your thorough critique has significantly contributed to the improvement of our paper, ensuring that it meets the high standards of scientific communication and rigor.

Thank you once again for your constructive feedback.

 

Kind regards,

Firoozi

 

Reviewer 1

The manuscript is problematic in two ways: some of the facts are not accurate and some of the text and facts are very redundant.

Regarding accuracy, facts such as stating that carbon fiber are interesting for wind turbine blades because of their strength to weight ratio is not correct. It is because of their stiffness to weight ratio. Carbon fibers also don’t bring better recyclability to wind turbine blades. Another example of inaccuracy can be found in the section dedicated to recycling, where the re-wind network project is mentioned in the section on chemical recycling. This network is not performing chemical recycling of blades, but repurposing of blades. Repurposing is not mentioned as an end-of-life option. This is an indication that the authors probably have not checked the reference. Finally, a number of places lack references, such as from line 1244 “With an increasing focus on sustainability, new standards are also being developed to address the environmental impact […].” There are no reference given for these new standards after that sentence and the reference given at the end of the paragraph line 1251, reference 67 is about offshore wind turbines and mainly about metals and monopile design.

Regarding redundancies, below is an example on the words “carbon fiber”. Carbon fiber is mentioned 16 times throughout the manuscript. In 11 cases the sentence summarizes the properties of carbon fiber. This is not needed, just one time would be enough. In addition, the sentence always mentions the positive side of carbon fibres, but not the negative ones.

1. From Line 82:“Carbon fiber composites offer unparalleled strength-to-weight ratios and fatigue resistance, enabling the design of longer, more durable blades that enhance the energy capture of wind turbines”

respond

Thank you for your valuable feedback on the role of carbon fibers in wind turbine blades. We acknowledge the inaccuracy in our description of carbon fibers' properties and appreciate your clarification regarding the importance of the stiffness-to-weight ratio over the strength-to-weight ratio for these materials in wind turbine applications.

In response to your comment, we have revised Line 82 as follows:

Old Text: "Carbon fiber composites offer unparalleled strength-to-weight ratios and fatigue resistance, enabling the design of longer, more durable blades that enhance the energy capture of wind turbines."

Revised Text: "Carbon fiber composites are chosen for their superior stiffness-to-weight ratio, enabling the design of longer and more robust blades that enhance the energy capture of wind turbines. These materials also help to reduce turbine loads and extend operational lifespans, contributing to the economic viability of wind energy projects."

 

2. From line 123:“[…] major innovations such as Carbon Fiber Reinforced Polymer (CFRP) for enhanced strength-to-weight ratios, to recent advances in bio-based composites and nano-enhanced materials.”

respond

Thank you for highlighting the inaccuracy in our description of the properties of Carbon Fiber Reinforced Polymer (CFRP) in wind turbine blade applications. We agree that the stiffness-to-weight ratio is a more relevant property in this context than the previously mentioned strength-to-weight ratio.

In line with your feedback, we have revised Line 123 to accurately reflect this:

Old Text: "[…] major innovations such as Carbon Fiber Reinforced Polymer (CFRP) for enhanced strength-to-weight ratios, to recent advances in bio-based composites and nano-enhanced materials."

Revised Text: "Figure 1 illustrates the significant milestones in the evolution of materials used in wind turbine blades from the 1980s to the present. Beginning with the introduction of Glass Fiber Reinforced Polymer (GFRP) for its strength and flexibility, the timeline progresses through major innovations such as Carbon Fiber Reinforced Polymer (CFRP) for its superior stiffness-to-weight ratios, leading to recent advances in bio-based composites and nano-enhanced materials. These developments underscore the industry’s focus on optimizing blade performance through cutting-edge material science, ensuring turbines are not only more efficient but also environmentally sustainable. Each phase represents a pivotal advancement in the design capabilities and sustainability objectives of wind energy technology."

 

3. From line 137: “the use of carbon fiber composites, which offer an exceptional strength-to-weight ratio, superior stiffness, and increased fatigue resistance, making them ideal for large-scale turbine applications

respond

We appreciate your attention to the properties of carbon fiber composites as described in our manuscript. You correctly noted that our initial emphasis on the strength-to-weight ratio was misplaced in the context of wind turbine applications, where the stiffness-to-weight ratio is more critical.

Accordingly, we have made the following revision to Line 137:

Old Text: "In recent years, the materials science field has made significant strides in developing innovative materials tailored for wind turbine blade construction. These advances aim to enhance the performance, durability, and environmental sustainability of blades, addressing the limitations of traditional materials like fiberglass and metals. One of the most promising developments is the use of carbon fiber composites, which offer an exceptional strength-to-weight ratio, superior stiffness, and increased fatigue resistance, making them ideal for large-scale turbine applications [13]."

Revised Text: "In recent years, the materials science field has made significant strides in developing innovative materials tailored for wind turbine blade construction. These advances aim to enhance the performance, durability, and environmental sustainability of blades, addressing the limitations of traditional materials like fiberglass and metals. A standout development is the use of carbon fiber composites, prized primarily for their superior stiffness-to-weight ratio and enhanced fatigue resistance, which make them ideal for large-scale turbine applications [13]."

 

4. From line 141: “Carbon fiber's lightweight properties allow for the design of longer blades that can capture more wind energy without compromising structural integrity.”

respond

Thank you for your continued insights and detailed feedback. We acknowledge the need to accurately reflect the properties of carbon fiber composites in wind turbine blade applications, particularly highlighting the importance of stiffness-to-weight ratio.

We have revised Line 141 to better reflect this understanding:

Old Text: "Carbon fiber's lightweight properties allow for the design of longer blades that can capture more wind energy without compromising structural integrity."

Revised Text: "Due to their excellent stiffness-to-weight ratio, carbon fibers enable the design of longer blades that can capture more wind energy without compromising structural integrity. This material also reduces the overall weight of the turbine, leading to lower mechanical stress on other turbine components and extending the operational lifespan of the turbines. Furthermore, the integration of nanotechnology has enhanced composite materials by allowing nano-fillers to be embedded into resins, which improve the mechanical and thermal properties of the blades. Such nanocomposites are not only stronger and more durable but also exhibit improved resistance to environmental factors like UV radiation and moisture [14]."

 

5. From line 165: “Highlighting key parameters such as density, tensile strength, and flexibility, this table elucidates the differences between traditional materials like metals and fiberglass, and more advanced composites like carbon fiber and bio-based al- 167 ternatives.

respond

Thank you for your insightful feedback on the presentation of material properties and environmental impacts in our manuscript. We recognize the necessity of providing a clear and concise comparison that avoids redundancy while accurately detailing the unique attributes and environmental implications of each material.

In response to your comment, we have revised the text as follows to enhance clarity and focus:

Old Text: "Table 1 presents a comparative analysis of the physical properties and environmental impacts of various materials used in the construction of wind turbine blades. Highlighting key parameters such as density, tensile strength, and flexibility, this table elucidates the differences between traditional materials like metals and fiberglass, and more advanced composites like carbon fiber and bio-based alternatives..."

Revised Text: "Table 1 provides a comparative analysis of the physical properties and environmental impacts of materials used in wind turbine blade construction. It underscores key attributes such as density, tensile strength, and flexibility, delineating the contrasts between traditional materials like metals and fiberglass, and advanced composites such as carbon fiber and bio-based alternatives..."

 

6. From line 183: Materials like carbon fiber composites and bio-based composites not only enhance the physical properties of blades but also extend their operational life and reduce maintenance costs, fundamentally changing the economics of wind energy [16].

respond

Thank you for your feedback on the description of how carbon fiber composites and bio-based composites impact the economics of wind energy. We agree that a more detailed explanation is necessary to adequately convey the specific benefits and economic implications of these materials.

In response to your comment, we have revised the text as follows to clarify these points:

Old Text: "The introduction of advanced materials into wind turbine blade manufacturing has significantly influenced the performance and durability of these critical components. Materials like carbon fiber composites and bio-based composites not only enhance the physical properties of blades but also extend their operational life and reduce maintenance costs, fundamentally changing the economics of wind energy [16]."

Revised Text: "The integration of advanced materials into wind turbine blade manufacturing has markedly impacted the performance and longevity of these critical components. Carbon fiber composites, notable for their stiffness-to-weight ratio, contribute to longer blade lifespans and lower maintenance needs by reducing mechanical stress. Similarly, bio-based composites offer environmental advantages and cost reductions due to their sustainable nature and easier disposal processes, collectively transforming the economic landscape of wind energy operations [16]."

 

7. From line 187: Carbon fiber's high stiffness and fatigue resistance allow for the construction of longer blades that are resilient under fluctuating and harsh wind conditions.

respond

Thank you for your observations on our description of carbon fiber’s impact on wind turbine blade design. Your feedback has helped us refine our discussion of how carbon fiber’s unique properties contribute to turbine efficiency and durability.

In response to your comment, we have made the following revisions to Line 187:

Old Text: "Carbon fiber's high stiffness and fatigue resistance allow for the construction of longer blades that are resilient under fluctuating and harsh wind conditions. This capability translates into higher efficiency as blades can operate optimally across a broader range of wind speeds, capturing more energy and increasing the overall output of wind turbines. "

Revised Text: "Carbon fiber's superior stiffness and fatigue resistance facilitate the construction of longer, more resilient blades capable of withstanding fluctuating and harsh wind conditions. This characteristic allows the blades to maintain optimal performance across a wider range of wind speeds, enhancing energy capture and thus increasing the overall efficiency of wind turbines. "

 

8. From line 192: Moreover, the reduced weight of carbon fiber blades decreases the load on turbine bearings and structures, thereby minimizing wear and tear and enhancing the lifespan of the turbine's mechanical components [17].

respond

Thank you for pointing out the need to further detail the advantages of using carbon fiber in wind turbine blades regarding mechanical stress and longevity. We agree that the statement could benefit from a clearer expression of these relationships.

In response to your comment, we have revised the text as follows to enhance the description and underscore the mechanical benefits:

Old Text: "Moreover, the reduced weight of carbon fiber blades decreases the load on turbine bearings and structures, thereby minimizing wear and tear and enhancing the lifespan of the turbine's mechanical components [17]."

Revised Text: "Moreover, the lighter weight of carbon fiber blades significantly reduces the load on turbine bearings and supporting structures. This reduction in mechanical stress not only minimizes wear and tear but also substantially extends the operational lifespan of the turbine’s mechanical components [17]."

 

9. From line 239: Carbon fiber composites represent a significant advancement, delivering high energy efficiency due to their superior strength-to-weight ratio and excellent durability which reduces the frequency and costs of maintenance.

respond

Thank you for your comprehensive review, which has helped us identify several areas for improvement in terms of accuracy and redundancy within our manuscript. We acknowledge the issues raised and have undertaken a thorough revision to address these concerns effectively. In response to the specific point about Line 239, we have revised the text as follows:

Old Text: "Carbon fiber composites represent a significant advancement, delivering high energy efficiency due to their superior strength-to-weight ratio and excellent durability which reduces the frequency and costs of maintenance."

Revised Text: "Carbon fiber composites mark a pivotal advancement in wind turbine blade technology, significantly enhancing energy efficiency due to their outstanding stiffness-to-weight ratio. This key attribute not only ensures improved blade performance under diverse operational conditions but also contributes to reduced maintenance needs and costs by bolstering durability."

 

10. From line 591: In contrast, carbon fiber composites provide an improved profile with excellent strength and better recyclability, yet they still carry a moderate carbon footprint.

respond

Thank you for your comprehensive and insightful feedback, which has been invaluable in enhancing the accuracy and reducing redundancy within our manuscript. Regarding the specific comment on Line 591, we have revised the text as follows to accurately reflect the environmental profile of carbon fiber composites:

Old Text: "In contrast, carbon fiber composites provide an improved profile with excellent strength and better recyclability, yet they still carry a moderate carbon footprint."

Revised Text: "In contrast, while carbon fiber composites offer an improved performance profile with excellent stiffness and durability, they have limitations regarding recyclability and still possess a moderate carbon footprint. Bio-composites emerge as the most sustainable option, offering adequate mechanical properties combined with excellent recyclability and a significantly reduced carbon footprint, aligning with the industry’s increasing focus on minimizing environmental impacts throughout the lifecycle of turbine components."

 

11. From line 1118: Innovations in materials such as carbon fiber composites used in projects like the Gansu Wind Farm offer improved durability and performance under harsh conditions.

respond

Thank you for pointing out the need for clarity in our description of the benefits provided by carbon fiber composites in wind turbine applications. In response to your comment, we have made the following revision to Line 1118:

Old Text: "Adopting advanced materials for turbine blades and establishing rigorous maintenance protocols are essential for enhancing the longevity and efficiency of wind turbines. Innovations in materials such as carbon fiber composites used in projects like the Gansu Wind Farm offer improved durability and performance under harsh conditions."

Revised Text: "Adopting advanced materials for turbine blades and establishing rigorous maintenance protocols are essential for enhancing the longevity and efficiency of wind turbines. Notably, the use of carbon fiber composites in projects like the Gansu Wind Farm enhances durability and performance under harsh conditions, thanks to their superior stiffness-to-weight ratio. Additionally, the implementation of predictive maintenance strategies, as exemplified by the Block Island Wind Farm where sensors monitor blade integrity and predict potential failures, can significantly reduce downtime and operational costs."

 

12. Finally, an example combining both inaccuracy and redundancy, the strength to ratio of carbon fiber, which is not the reason why carbon fibers are used in blades is mentioned in 4 occasions as:
13. unparalleled strength-to-weight ratios
14. enhanced strength-to-weight ratios
15. exceptional strength-to-weight ratio
16. superior strength-to-weight ratio

respond

Thank you for your critical observations regarding our manuscript’s description of carbon fiber composites. We acknowledge the inaccuracies related to the properties of carbon fiber, specifically its stiffness-to-weight ratio, which is a more relevant attribute for wind turbine blade applications than the previously mentioned strength-to-weight ratio.

In response to your feedback, we have carefully revised all instances where carbon fiber composites were inaccurately described:

• We have corrected each mention of the "strength-to-weight ratio" to "stiffness-to-weight ratio" throughout the document to align with the correct material properties that influence their application in wind turbine blades.
• We have also minimized redundancy by ensuring that each mention of carbon fiber's properties is contextually necessary and provides new information relevant to the section's focus.

These revisions aim to enhance the accuracy of our manuscript and provide readers with a precise understanding of why carbon fiber composites are utilized in wind turbine blade construction, reflecting the latest developments and research in material science within the wind energy sector.

Reviewer 2 Report

Comments and Suggestions for Authors

The authors present a very interesting review article on the design of Wind Turbine Blades.  

Having read the article, I feel I must make the following self-reflections.

1.- The structure of the article is appropriate, the authors analyse in an orderly manner the main aspects of the life cycle of Wind Turbine Blades.

2- The figures and examples are very informative.  I think they are totally appropriate for a ‘scientific divulgation magazine’.  This led me to ask myself if the article has a place in the ‘Sustainability’ magazine.  And I believe that it does make sense to publish it in this journal.

I have some questions and considerations for minor improvements to the document:

- Figure 2: It is important to point out where these profiles have been obtained from.  Since the authors have not designed them, it is necessary to indicate their source(s).

- Figure 4: If the simulation has been carried out by the authors, I would like them to comment on it further.

-  Table 5: If we analyse the values of e.g. Carbon Footprint.  The authors indicate that it can be High, Medium, Low or Very High.  This category of impacts does not indicate anything of interest.  The value ‘Very High’, on which reference value is it taken?  For example over 200 kg CO2 eq.  It is important to clarify this doubt for all the columns of the table and for the rest of the tables where this impact assessment is used.

Finally, I must reiterate that it has been very interesting and informative to read the document.

 

Comments on the Quality of English Language

I am not from a country where English is my native language.  With this caveat, I would like to point out that a minor editing of English language is required.

Author Response

Response to Reviewer 2:

 

Dear Reviewer 2,

Thank you for your thoughtful and positive feedback on our manuscript regarding the design of wind turbine blades. We are pleased to hear that the structure of the article and the illustrative content met your expectations and contributed effectively to the discourse on sustainability in wind energy.

Addressing Your Comments and Implementations:

1. We are grateful for your recognition of the article's structured analysis of wind turbine blade life cycles and its suitability for publication in 'Sustainability' magazine. Your affirmation reinforces our intent to contribute valuable insights to the field.
2. We appreciate your acknowledgment of the figures and examples provided. Based on your suggestion, we have ensured that all figures are not only informative but also accurately sourced and cited, enhancing the article's reliability and educational value. Revisions Made:
3. We have added detailed sources and expanded the simulation data for figures where this was previously lacking, ensuring complete transparency about the origins and implications of the depicted data.
4. In response to your advice on quantifying impact assessments in tables, we have included specific metrics and benchmarks, particularly concerning environmental impacts like carbon footprints, to provide a clearer, more quantitative understanding.
5. To facilitate an easy review of the changes made, we have highlighted all revisions in blue within the manuscript. This should help in quickly locating and reviewing the enhancements based on your constructive feedback.

We believe these amendments have significantly strengthened the manuscript, aligning it closely with the journal's standards and thematic focus. Your expert insights have been instrumental in refining our presentation and depth of analysis.

Thank you once again for your comprehensive review and supportive words. We look forward to the possibility of our revised manuscript making a substantial contribution to 'Sustainability' magazine.

 

Kind regards,

Firoozi

 

Reviewer 2

Comments and Suggestions for Authors

The authors present a very interesting review article on the design of Wind Turbine Blades.

Having read the article, I feel I must make the following self-reflections.

1.- The structure of the article is appropriate, the authors analyse in an orderly manner the main aspects of the life cycle of Wind Turbine Blades.

2- The figures and examples are very informative.  I think they are totally appropriate for a ‘scientific divulgation magazine’.  This led me to ask myself if the article has a place in the ‘Sustainability’ magazine.  And I believe that it does make sense to publish it in this journal.

I have some questions and considerations for minor improvements to the document:

1. Figure 2: It is important to point out where these profiles have been obtained from.  Since the authors have not designed them, it is necessary to indicate their source(s).

respond

Thank you for your insightful comment concerning the source of the profiles depicted in Figure 2. We appreciate your attention to detail and the importance of proper attribution in scholarly work.

In response to your observation, we have updated the caption of Figure 2 to include the specific sources from which these profiles were obtained. Here is the revised caption for Figure 2:

Revised Caption for Figure 2: “Figure 2 presents a side-by-side comparison of airfoil profiles designed for wind turbine blades, categorizing them based on blade size. On the left, the "Thick-Airfoil Family for Large Blades" showcases profiles that are optimized for larger turbine blades, characterized by their robustness and enhanced performance at lower wind speeds. These include the Tip-Region Airfoil, Primary Outboard Airfoil, and Root Region Airfoil, each progressively thicker to withstand higher structural loads. On the right, the "Thin-Airfoil Family for Medium Blades" demonstrates airfoils suited for medium-sized blades, offering improved efficiency and speed response in moderate wind conditions. These thinner profiles are tailored to balance lift and drag effectively, optimizing the aerodynamic performance across various segments of the blade. This comparison highlights the design considerations necessary to enhance the aerodynamic efficiency and structural integrity of turbine blades tailored to different operational demands and turbine sizes. Profiles adapted from Firoozi, A. A. et al. [74].”

 

2. Figure 4: If the simulation has been carried out by the authors, I would like them to comment on it further.

respond

Thank you for your interest in the simulations depicted in Figure 4 and for requesting further details about them. To clarify, the simulations showcased in Figure 4 have not been conducted directly by our research team. Instead, they are representative of comprehensive studies in the field, particularly focusing on the application of vortex generators on wind turbine blades.

Explanation and Source Attribution:

• The primary purpose of incorporating Figure 4 in our review is to visually demonstrate the established aerodynamic impacts of vortex generators, as documented in the scientific literature. This includes how these devices maintain airflow attachment, thereby enhancing blade efficiency and reducing energy losses due to flow separation.
• The images and the simulations illustrated are adapted from key research studies that have conducted detailed Computational Fluid Dynamics (CFD) analyses on the role of vortex generators. Specifically, these studies explore their effectiveness in improving the aerodynamic performance of wind turbine blades under various operational conditions.
• For an in-depth understanding and technical validation of the simulation results presented, we direct readers to the original studies. These are comprehensively cited in our references section, particularly [specific studies or papers with citations], where these aerodynamic analyses have been extensively discussed and validated through empirical data and advanced modeling techniques.

While our review synthesizes findings from multiple sources, we ensure that all graphical representations and derived conclusions are accurately credited and represent the current consensus in the field. This approach helps in maintaining the scientific integrity of the review while providing readers with a clear, concise understanding of complex aerodynamic phenomena.

“75.     Sy, M. S., Abuan, B. E., & Danao, L. A. M. (2020). Aerodynamic investigation of a horizontal axis wind turbine with split winglet using computational fluid dynamics. Energies, 13(18), 4983. https://doi.org/10.3390/en13184983  

76. Jiang, R., Zhao, Z., Liu, H., Wang, T., Chen, M., Feng, J., & Wang, D. (2022). Numerical study on the influence of vortex generators on wind turbine aerodynamic performance considering rotational effect. Renewable Energy, 186, 730-741. https://doi.org/10.1016/j.renene.2022.01.026
77. Manolesos, M., Chng, L., Kaufmann, N., Ouro, P., Ntouras, D., & Papadakis, G. (2023). Using vortex generators for flow separation control on tidal turbine profiles and blades. Renewable Energy, 205, 1025-1039. https://doi.org/10.1016/j.renene.2023.02.009”
78. Table 5: If we analyse the values of e.g. Carbon Footprint.  The authors indicate that it can be High, Medium, Low or Very High.  This category of impacts does not indicate anything of interest.  The value ‘Very High’, on which reference value is it taken?  For example over 200 kg CO2 eq.  It is important to clarify this doubt for all the columns of the table and for the rest of the tables where this impact assessment is used.

Finally, I must reiterate that it has been very interesting and informative to read the document.

respond

Thank you for your constructive feedback regarding the environmental impact categorizations in Table 5. We appreciate your suggestion to provide more precise and meaningful data concerning the carbon footprint and other environmental metrics of the materials used in wind turbine blades.

Revisions Made:

• We have revised Table 5 to include quantitative indicators of the carbon footprint for each material type, expressed in kilograms of CO2 equivalent per kilogram of material (kg CO2 eq. per kg). These figures are based on life-cycle assessment data available in the literature, which considers the environmental impact of extraction, processing, use, and disposal of these materials.
• The values for carbon footprint are derived from a range of studies that perform detailed environmental impact assessments specific to each material. For example, the figure for aluminum is based on data indicating high energy consumption during production, which significantly increases its carbon footprint.
• We have added a note under the table clarifying that these values are simplified averages that provide a general understanding of each material’s environmental impact. For a detailed breakdown, readers are referred to specific life-cycle assessment studies that delve into granular assessments of these materials.

Reviewer 3 Report

Comments and Suggestions for Authors

A very comprehensive research and manuscript. All aspects, even recycling) are covered.

It is well-written, well-structured, and the case studies are very interesting.

No comments

Author Response

Response to Reviewer 3:

Dear Reviewer 3,

Thank you very much for your encouraging comments and for recognizing the comprehensiveness and structure of our manuscript. We are delighted to hear that the case studies and the coverage of various aspects, including recycling, were well-received and found to be of interest.

Your feedback is greatly appreciated and serves as a valuable affirmation of our efforts to contribute meaningful and well-rounded research to the field.

Thank you once again for your supportive and constructive review.

Kind regards,

Firoozi

 

Reviewer 3

A very comprehensive research and manuscript. All aspects, even recycling) are covered.

It is well-written, well-structured, and the case studies are very interesting.

No comments