The Use of Solar Thermal Heating in SPIRE and Non-SPIRE Industrial Processes
Round 1
Reviewer 1 Report
1. The abstract states that the authors have implemented a new solar thermal system developed within the EU-ASTEP project. Unfortunately, this system and its description are not presented in the article. The lack of a description of the proposed system makes it difficult to understand what exactly the authors have developed. 2. The abstract also states that the authors carried out calculations of the theoretical and technical potential of using the ASTEP system in industrial processes, which showed the effectiveness of the scheme. According to the authors, implementing their scheme led to a reduction in the GHG emissions by 24 thousand kt of CO2. The article itself does not present any calculations that would confirm the obtained GHG emissions reduction stated in the abstract. 3. I recommend it to reflect in the article the proposed system as an algorithm and to give its description. I also recommended it to show what the efficiency depends on and how the efficiency values were obtained. Provide a comparative analysis of the developed system with existing analogues.Author Response
Dear Reviewer,
We thank you for all your comments and suggestions All of them have been considered and amendments made.
We hope that the paper is suitable for publications and look forward to your favorable response.
Kind regards,
Valentina
- The abstract states that the authors have implemented a new solar thermal system developed within the EU-ASTEP project. Unfortunately, this system and its description are not presented in the article. The lack of a description of the proposed system makes it difficult to understand what exactly the authors have developed.
Response: It has been corrected. The section that reviews the ASTEP system (Lines 360-376) has been extended to use more references and include a more detailed description. The ASTEP system is a SHIP system developed by the ASTEP project to use a novel Fresnel collector with slightly bent mirrors and double tracking to achieve a higher operating temperature, higher optical efficiency, lower energy losses and a more uniform flux intensity along the receiver allowing the collector to operate in low and high irradiance locations. This system has been presented in this paper as a novel SHIP system that can reach more processes and industries with higher temperature requirements in lower irradiance regions and used to evaluate the potential SHIP systems in EU industries
- The abstract also states that the authors carried out calculations of the theoretical and technical potential of using the ASTEP system in industrial processes, which showed the effectiveness of the scheme. According to the authors, implementing their scheme led to a reduction in the GHG emissions by 24 thousand kt of CO2. The article itself does not present any calculations that would confirm the obtained GHG emissions reduction stated in the abstract.
Response: It has been corrected. The section on the environmental impact of the ASTEP system (Lines 529-540) has been extended to better explain how the GHG emissions reduction value was obtained. The ASTEP system has a technical potential that represents 3% of the total energy consumption of EU28 industries. Accounting that from the annual GHG emissions of the EU28 Industries (793 thousand kt CO2 equivalent), it was estimated that ASTEP system can reduce GHG emissions by 24 thousand kt CO2 equivalent annually.
- I recommend it to reflect in the article the proposed system as an algorithm and to give its description. I also recommended it to show what the efficiency depends on and how the efficiency values were obtained. Provide a comparative analysis of the developed system with existing analogues.
Response: It has been corrected. The section that reviews the ASTEP system (Lines 360-376) has been extended to present the enhancements made and efficiency values improved. The ASTEP project enhanced the efficiency of the novel Fresnel collector by using slightly bent mirrors with double tracking which led to a higher operating temperature, higher optical efficiency, lower energy losses and more uniform flux intensity along the receiver. In addition, they used a PCM storage system to help meet the continuous demand of industrial processes increasing the overall efficiency.
Reviewer 2 Report
Dear authors,
Thank you for submitting your paper for review. After careful consideration, I would like to provide the following comments to help improve the quality of submitted manuscript.
Title and Abstract: The paper appears to be a review paper, so it would be beneficial to reflect this in the title and abstract. Additionally, it would be helpful to provide a more clear explanation of the novelty of the review and set the context for the rest of the paper.
Literature Review and Methodology: The literature review seems diverse, but it is not clear what exactly is going to be extracted from it. I recommend defining the plan of investigation more clearly and outlining the key parameters and important factors that will be discussed or reviewed. To help readers follow the review, a table summarizing the extracted important data at the end of each section or in total may be useful.
It would be helpful to explain any abbreviations before using them in the manuscript. For example, if the manuscript includes the terms SPIRE (abstract) and GHG (context), it would be beneficial to explain what these terms mean. This will ensure that readers understand the terms and can follow the paper more easily.
Terminology: To ensure clarity and understanding, it is recommended to use appropriate and related terminology throughout the manuscript. For example, a more suitable phrase than "One of the rare papers published by Plaza et al." may be used.
Certainty: It is suggested to avoid using definite terms such as "there is only one SHIP system recorded worldwide and is located in Spain" or "There are thirty-five SHIP systems used for the dairy industry". There is always some level of uncertainty about the quality of data gathered, so it would be more appropriate to use terms such as "it is believed" or "it is estimated".
Conclusion and Recommendations: The paper lacks a comprehensive conclusion and recommendations for future research. To strengthen the contribution of the paper to the field, it would be beneficial to discuss the limitations of the review, such as the quality of the studies included or the generalizability of the results, and again summarize the main findings of the review.
Sincerely,
Author Response
Dear Reviewer,
We thank you for all your comments and suggestions. All of them have been considered and amendments made.
We hope that the paper is suitable for publications and look forward to your favorable response.
Kind regards,
Valentina
Literature Review and Methodology: The literature review seems diverse, but it is not clear what exactly is going to be extracted from it. I recommend defining the plan of investigation more clearly and outlining the key parameters and important factors that will be discussed or reviewed. To help readers follow the review, a table summarizing the extracted important data at the end of each section or in total may be useful.
Response: It has been corrected. Each section now contains an introductory paragraph at the very beginning (Lines 85-86, 243-245). Tables 1 and 2 were developed and added at the end of each section to highlight the main outcomes and identify the limitation of exiting SHIP systems in Lines 225-238 and 345-357. These limitations were then used to highlight the advantages of the ASTEP system in Lines 360-376.
It would be helpful to explain any abbreviations before using them in the manuscript. For example, if the manuscript includes the terms SPIRE (abstract) and GHG (context), it would be beneficial to explain what these terms mean. This will ensure that readers understand the terms and can follow the paper more easily.
Response: It has been corrected. All the abbreviation has been considered and amended accordingly.
Terminology: To ensure clarity and understanding, it is recommended to use appropriate and related terminology throughout the manuscript. For example, a more suitable phrase than "One of the rare papers published by Plaza et al." may be used.
Response: It has been corrected and “one of the rare papers published” have been removed. (Lines 136)
Certainty: It is suggested to avoid using definite terms such as "there is only one SHIP system recorded worldwide and is located in Spain" or "There are thirty-five SHIP systems used for the dairy industry". There is always some level of uncertainty about the quality of data gathered, so it would be more appropriate to use terms such as "it is believed" or "it is estimated".
Response: It has been corrected. The manuscript has been reviewed and the use of definite terms has been avoided in Lines 90, 143, 178-179, 219, 247, 254, 281, 309 and 324.
Conclusion and Recommendations: The paper lacks a comprehensive conclusion and recommendations for future research. To strengthen the contribution of the paper to the field, it would be beneficial to discuss the limitations of the review, such as the quality of the studies included or the generalizability of the results, and again summarize the main findings of the review.
Response: It has been corrected. The main finding of the paper and recommendations for future research have been added to the conclusion (Lines 542-567).
Author Response File: 
Author Response.docx
Reviewer 3 Report
line 182 please correct the temperature
line 292 is it paper industry or textile industry?
reference 56 is not used in the scientific paper
Author Response
Dear Reviewer,
We thank you for all your comments and suggestions All of them have been considered and amendments made.
We hope that the paper is suitable for publications and look forward to your favorable response.
Kind regards,
Valentina
line 182 please correct the temperature
Response: It has been corrected. The correct temperature is 1200-1750 oC (Line 194)
line 292 is it paper industry or textile industry?
Response: It has been corrected. It is the textile industry (Line 324)
reference 56 is not used in the scientific paper
Response: It has been corrected. Reference 56 (now reference 64) is referenced in line 492
Author Response File: Author Response.docx
Reviewer 4 Report
Please find the comments file attached.
Comments for author File: 
Comments.pdf
Author Response
Dear Reviewer,
We thank you for all your comments and suggestions All of them have been considered and amendments made.
We hope that the paper is suitable for publications and look forward to your favorable response.
Kind regards,
Valentina
1- Manuscript English language editing is required. Even though the manuscript is generally wellwritten, there are numerous cases of minor grammatical inaccuracies and typos i.e: a- In line 20 instead of totalled is totaled and so on…
Response: It has been corrected. The manuscript was reviewed and grammatical inaccuracies and typos were corrected (Lines 22, 23, 47, 53, 62-63, 70, 74, 97, 115, 145, 150-169, 198, 210, 228-232, 276, 278, 284-285, 336, 351, 355, 435, 449, 479, 499, 501.
- Rewrite and rearrange the abstract and added some results.
Response: It has been corrected. The abstract has reviewed and results were included (Lines 9-24)
3- Please update the survey of related work literature. The updated literature review must put the problems of this work into a meaningful context and contain the latest insights on research in the field.
Response: It has been corrected. The literature review has been updated and additional references were added (Lines 169-176, 338-344; 366-371).
4- In the literature review, the author must put some results for the reference cited, and also to comparison section.
Response: Tables 1 and 2 were developed where additional results to compare and highlight limitations in current SHIP systems are presented. Accordingly, the text has been amended and it is included in Lines: 225-238 and 345-357.
5- The authors can consider this paper in your work for the introduction and their importance will help for the different points in your research as mentioned in the next statements (doi.org/10.1016/j.renene.2018.03.031) and (doi.org/10.1016/j.applthermaleng.2019.114156)
Response: References considered in line 418 numbered 61 and 62 as one of the more energy efficient solutions for the application of SHIP systems at low temperatures of below 150 oC
6- The numbering and fonts of the titles are wrong, as well as the figures and tables.
Response: It has been corrected. The sections numbers in Section 2 (Lines 79-239) and the font of all figures and tables have been corrected.
7- Please check the unit oC, especially in line 491 its written wrong.
Response: It has been corrected in lines 490, 505, 506, 548-549.
8- In Figures 1 and 2, the fonts and y-axis number must be edited.
Response: It has been corrected. Font of text in Figures 1 and 2 has been changed to match the font of the text of their titles (Lines 386-387 and 401-402)
9- Why is this review being effective way to overcome the limitations and operational problems?
Response: It has been corrected. The key findings of the review have been highlighted in tables 1 and 2 to help identify the limitations in existing SHIP systems (Lines 225-238 and 345-357). In addition, more references have been used to better describe the ASTEP system and its enhanced features (Lines 360-376). These were used to specify potential industries (Table 4) and processes (Table 5) for SHIP application
10- The conclusion section needs more clarity more main results.
Response: It has been corrected. The conclusion has been extended and more results were included (Lines: 542-567).
11- Add some recommendation statements at the end of the conclusion part.
Response: It has been corrected. Recommendations to both, researchers and industrial sectors, were presented (Lines 559-567)
Author Response File: Author Response.docx
Reviewer 5 Report
Information for Authors
The article submitted for review entitled "The use of Solar Thermal Heating to the SPIRE and Non-SPIRE 2 Industrial Processes" raises the problem of the use of solar thermal energy systems to SPIRE and non-SPIRE industries and use a novel solar Fresnel collector for generating temperature of up to 400oC. The issue of publication is extremely important from the point of view of global reduction of CO2 emissions. The article broadly presents the problem of the use of solar energy in various industries.
The findings obtained in the reviewed article on the basis of the overview are a novelty.
The results are presented clearly and the conclusions are shortly formulated, highlighting the most important insights from the research.
I would like to make remark regarding the content of the article.
The publication analyzes a large amount of data from a wide range of manufacturing industries in Europe. The benefits of using The new solar thermal ASTEP system have been thoroughly proven. This contrasts with poor conclusions. Based on the previous analyzes from point 4, I am asking you to extend point 5 with some additional important conclusions and possible comments regarding the future development of the ASTEP system.
Author Response
Dear Reviewer,
We thank you for all your comments and suggestions All of them have been considered and amendments made.
We hope that the paper is suitable for publications and look forward to your favorable response.
Kind regards,
Valentina
The article submitted for review entitled "The use of Solar Thermal Heating to the SPIRE and Non-SPIRE 2 Industrial Processes" raises the problem of the use of solar thermal energy systems to SPIRE and non-SPIRE industries and use a novel solar Fresnel collector for generating temperature of up to 400oC. The issue of publication is extremely important from the point of view of global reduction of CO2 emissions. The article broadly presents the problem of the use of solar energy in various industries.
The findings obtained in the reviewed article on the basis of the overview are a novelty.
The results are presented clearly and the conclusions are shortly formulated, highlighting the most important insights from the research.
I would like to make remark regarding the content of the article.
The publication analyzes a large amount of data from a wide range of manufacturing industries in Europe. The benefits of using The new solar thermal ASTEP system have been thoroughly proven. This contrasts with poor conclusions. Based on the previous analyzes from point 4, I am asking you to extend point 5 with some additional important conclusions and possible comments regarding the future development of the ASTEP system.
Response: It has been corrected. The conclusion has been extended with more results and recommendations to future researchers (Lines: 542-567)
Author Response File: Author Response.docx
Reviewer 6 Report
It is presented a comprehensive review study of investigation the use of solar thermal energy systems to SPIRE (Sustainable Process Industry through Resource and Energy Efficiency) and non-SPIRE industries and use a novel solar Fresnel collector for generating temperature of up to 400oC. The main aim of this paper is to review systematically the use SHIP (Solar Heating for Industrial Processes) systems in SPIRE and non-SPIRE industries and evaluate quantitively the potential of a new ASTEP (Application of Solar Thermal Systems in Industrial Processes) concept for generating higher temperature of up to 400 oC for various industrial processes in EU.
In 2019 the industries in the EU launched a public-private partnership association named (SPIRE) representing 20% of the total EU manufacturing sector involving a great number of stakeholders and industries like cement, ceramics, chemicals, minerals and ores, non-ferrous metals, steel, and water. To increase the use of this novel solar Fresnel collector to the SPIRE industries located in the high and low irradiance regions, a novel solar thermal system was developed by EU-ASTEP project. This resulted with reduction of the GHG emissions by 24 thousand kt CO2 equivalent annually.
Well-arranged classification of heat demand per temperature ranges [TWh] for the EU28 industries and calculation the quantitative potential of the use of the ASTEP system was done.
The structure of paper is well organized, and the review study brings new findings, interesting information and knowledge.
Additionally, the manuscript contains no mistakes nor discrepancies of formal character.
Author Response
Dear Reviewer,
We really appreciate your kind feedback and comments.
Kind regards,
Valentina
Round 2
Reviewer 1 Report
The answers are inconclusive.
Author Response
Reviewer 1:
- The abstract states that the authors have implemented a new solar thermal system developed within the EU-ASTEP project. Unfortunately, this system and its description are not presented in the article. The lack of a description of the proposed system makes it difficult to understand what exactly the authors have developed.
Response: It has been corrected. The section that reviews the ASTEP system has been extended to use more references and include a more detailed description of its different components (Lines 360-385). The ASTEP system is a SHIP system developed by the ASTEP project to use a novel Fresnel collector and a state-of-art PCM storage to operate at temperatures of up to 400 oC in low and high irradiance regions. The novel collector consists of a rotating platform with concentrating linear Fresnel mirrors and an elevated receiver on top. A new Figure 1 was created. It has a double-tracking system and uses slightly bent mirrors with a modified slope to increase the efficiency of the collector and reduce its thermal losses. The state-of-art PCM storage consists of a shell enclosure and multiple tubes with inserts that create a honeycomb configuration. Its performance was enhanced by using an uneven configuration with Y-insert and an aluminium-silicon structure to increase the heat transfer between the HTF and PCM, subsequently increasing the efficiency of the storage system. These enhancements which allow the ASTEP system to operate at temperatures of up to 400 oC are considered in the evaluation of its quantitative potential in EU28 industries as explained in Lines 419-425.
- The abstract also states that the authors carried out calculations of the theoretical and technical potential of using the ASTEP system in industrial processes, which showed the effectiveness of the scheme. According to the authors, implementing their scheme led to a reduction in the GHG emissions by 24 thousand kt of CO2. The article itself does not present any calculations that would confirm the obtained GHG emissions reduction stated in the abstract.
Response: It has been added. The calculations of the GHG emission reduction have been shown in the section related to the environmental impact of the ASTEP system (Lines 578-593). The technical potential of the ASTEP system represents the annual energy saving that can be achieved when integrated to EU28 industries. This was found to be 96.3 TWh and represents 3% of their total energy consumption. Considering that the EU28 industries have an annual GHG emissions of 793 thousand kt CO2 equivalent, it was calculated that the ASTEP system can reduce these emissions by 24 thousand kt CO2 equivalent (3% of 793 thousand kt CO2 equivalent).
- I recommend it to reflect in the article the proposed system as an algorithm and to give its description. I also recommended it to show what the efficiency depends on and how the efficiency values were obtained. Provide a comparative analysis of the developed system with existing analogues.
Response: It has been corrected. More references have been used to describe how the ASTEP project is developing its system and a new Table 3 was created to compare the performance of its novel Fresnel collector to other concentrated collectors (Lines 386-409). The efficiency of the novel collector was improved by enhancing the concentration of the solar rays on the receiver to increase the optical efficiency and reduce thermal losses (Lines 363-372). It was calculated using a steady-state model of the ASTEP system developed in MATLAB and validated using the literature. The results showed the maximum efficiency of the novel collector was 85%. This was compared to other concentrated collectors that operate at similar temperatures in Table 3.
Author Response File: Author Response.docx
Reviewer 4 Report
Good job
Author Response
Thanks, We really appreciate your positive response.
Kr, Valentina
Round 3
Reviewer 1 Report
The answers are not convincing.
Author Response
Please see attached.
