A Review on Green Cooling: Exploring the Benefits of Sustainable Energy-Powered District Cooling with Thermal Energy Storage

Round 1

Reviewer 1 Report

The authors carried out a comprehensive review on the economic and environmental impacts of district cooling systems. 

For the biomass section, I strongly recommend to consult the following paper as it also considers envirnmental and economic aspect of low-enthalpy districts. You may cite that in your section 3.1. I have attached the paper here:

https://www.sciencedirect.com/science/article/pii/S2666278721000179

I also recommend the authors on the available tools/software or the general available/applicable formulation and bodelling of the environmental/economic aspects of the district energy systems. 

Number of references for a review paper is not enough and more literature is need to be reviewed.

 

Comments for author File: Comments.zip

Author Response

Reviewer 1

Reviewer question: For the biomass section, I strongly recommend consulting the following paper as it also considers environmental and economic aspect of low-enthalpy districts. You may cite that in your section 3.1. I have attached the paper here:

https://www.sciencedirect.com/science/article/pii/S2666278721000179

Authors' Response: The papers provided by the reviewer were found to be very useful and cited accordingly in the work (see reference list.). However, more detailed information was found in the papers and very helpful in enriching section 3.1 of the manuscript as could be seen highlighted in yellow.

Reviewer question I also recommend the authors on the available tools/software or the general available/applicable formulation and modeling of the environmental/economic aspects of the district energy systems. 

Authors' Response: Actually, the paper was intended to provide information on the economic and environmental impacts of district cooling systems, renewable energy-driven, and thermal energy storage integrated systems in order to identify the best and most efficient system among the three. However, the modeling of the economic and environmental aspects of the district cooling system was not part of the objectives of the paper and therefore, the reason for not incorporating that into the discussion.

Reviewer question; Number of references for a review paper is not enough and more literature is need to be reviewed.

Authors' Response: As suggested, the number of references was significantly improved.

Author Response File: Author Response.docx

Reviewer 2 Report

This paper provides a review of the economic and environmental impacts of the DCS, renewable, and TES with VCC-integrated technologies and suggests an economically viable route for achieving sustainability in the use of DCS technology. Overall, the authors have compiled a lot of literature on energy systems from the DCS perspective, but the content of the article needs to be supplemented and the writing needs to be improved.

1.      Introducing ‘Vapor Compression Chiller Integration into Thermal Energy Storage’ after the review of DCS and ‘Renewable energy integration into DCS’ is illogical. It is better to present review centered on district energy system and introduce energy storage from renewable energy access. Vapor compression chiller is a specific and small object, energy system should be reviewed from a more macro perspective.

2.      The content of the article needs to be further arranged. Relevant analysis of economic and environmental impacts about DCS, TES, VCC should be added. More references and reviews about renewable energy-driven systems are needed in Section 3 or 4.

3.      The frame of the article needs to be adjusted to meet the topic better. The text volume of Section 2 and 4 is much smaller than Section 3, and the materials about DCS in 3 needs to be reorganized together with Section 2.

4.      The conclusions of the summary in Table2 need further explanation, and the amount and representativeness of references sorted out in the table are insufficient.

5.      The role of the pictures in the article needs to be further explained. Whether these pictures are necessary since they are not really relevant to the review.

6.      In Section 3, why biomass energy, solar thermal energy, geothermal energy, solar photovoltaic, surface water is selected as the renewable energy? What about wind power, hydrogen and other energy sources?

7.      The quality of the writing must be significantly improved. The mistakes and errors of the article need to be corrected, such as:

1)      Section 2 and 3 have different indentation formats for paragraphs

2)      Section 5 has a different font size

3)      Section 3 has "." in title: ‘3. Renewable energy integration into DCS.’

4)      The paragraph of Figure 1 is not separated from the text

5)      The formats of figures are not consistent, such as "Figure 1:" "Fig. 2."

6)      Citation notation should be labeled with link

7.     Reference [42] is marked twice in the same place

Comments for author File: Comments.pdf

Author Response

Reviewer 2.

This paper provides a review of the economic and environmental impacts of the DCS, renewable, and TES with VCC-integrated technologies and suggests an economically viable route for achieving sustainability in the use of DCS technology. Overall, the authors have compiled a lot of literature on energy systems from the DCS perspective, but the content of the article needs to be supplemented and the writing needs to be improved.

Reviewer’s questions

1. Introducing ‘Vapor Compression Chiller Integration into Thermal Energy Storage’ after the review of DCS and ‘Renewable energy integration into DCS’ is illogical. It is better to present a review centered on the district energy system and introduce energy storage from renewable energy access. Vapor compression chiller is a specific and small object, energy system should be reviewed from a more macro perspective.

Authors' response: As suggested, the title was recasted to give a better description of the content in the manuscript. Besides, the energy storage system driven by renewable sources was presented in more detail.

 

2. The content of the article needs to be further arranged. A relevant analysis of the economic and environmental impacts of DCS, TES, and VCC should be added. More references and reviews about renewable energy-driven systems are needed in Section 3 or 4.

Authors' response: this has been addressed (see subsection 3.6)

Reviewer question 3; The frame of the article needs to be adjusted to meet the topic better. The text volume of Section 2 and 4 is much smaller than in Section 3, and the materials about DCS in 3 needs to be reorganized together with Section 2.

Authors' response: Various types of DCS and their benefits and challenges were presented to give more information on the DSC. Section 2.1.

Reviewer question 4; The conclusions of the summary in Table 2 need further explanation, and the amount and representativeness of references sorted out in the table are insufficient.

Authors' response: The conclusion of the summary was revised and more references were added.

Reviewer question 5; The role of the pictures in the article needs to be further explained. Whether these pictures are necessary since they are not really relevant to the review.

Authors response: The pictures were drawn and incorporated into the paper, just to give a glimpse on some of the description of DCS network and water surface of the DCS.

Reviewer question  6; In Section 3, why biomass energy, solar thermal energy, geothermal energy, solar photovoltaic, and surface water is selected as renewable energy? What about wind power, hydrogen, and other energy sources?

Authors' response: Hydrogen and wind can be used as fuel sources in district cooling systems, but they are not commonly used energy sources in this application. District cooling systems typically use electricity or waste heat from industrial processes as a source of energy. Hydrogen is still being explored as a source of energy for various applications, including cooling, and its usage in district cooling systems may increase in the future as technology advances and becomes more widespread.

Reviewer question 7;      The quality of the writing must be significantly improved. The mistakes and errors in the article need to be corrected, such as:

1) Sections 2 and 3 have different indentation formats for paragraphs

2)      Section 5 has a different font size

3)      Section 3 has "." in title: ‘3. Renewable energy integration into DCS.’

4)      The paragraph of Figure 1 is not separated from the text

5)      The formats of figures are not consistent, such as "Figure 1:" "Fig. 2."

6)      Citation notation should be labeled with a link.

7. Reference [42] is marked twice in the same place

Authors' response: All observations raised in question 7, were corrected accordingly.

Author Response File: Author Response.docx

Reviewer 3 Report

Please see the attachment.  

Comments for author File: Comments.pdf

Author Response

Authors' Responses to Reviewer 3

The authors are not disputing all the observations and comments highlighted by the reviewer, however, the present work focused on the following objectives.

To review the current state of the art in renewable energy-driven district cooling systems with thermal energy storage.

To analyze the economic and environmental impacts of these systems, including their energy efficiency and greenhouse gas emissions.

To examine the benefits and challenges associated with integrating renewable energy and thermal energy storage into district cooling systems.

To compare the performance of renewable energy-driven district cooling systems with thermal energy storage to traditional air conditioning systems.

To provide recommendations for the future development and implementation of renewable energy-powered district cooling systems with thermal energy storage.

To highlight the potential for these systems to contribute to a more sustainable and efficient built environment.

Besides, the difference between the paper "Green Cooling: Exploring the Benefits of Renewable Energy-Powered District Cooling with Thermal Energy Storage" from related kinds of literature can depend on the specific focus and approach taken in the paper. However, some possible differences are:

Integrated approach: This paper takes an integrated approach to analyze the economic and environmental impacts of renewable energy-driven district cooling systems with thermal energy storage, which is different from studies that focus only on one aspect, such as energy efficiency or renewable energy integration.

Focus on thermal energy storage: This paper places a special emphasis on the role of thermal energy storage in renewable energy-powered district cooling systems, which is a unique aspect compared to other studies that may not address this component or only consider it briefly.

Recommendations for implementation: This paper provides specific recommendations for the future development and implementation of these systems, which is a practical and actionable aspect that sets it apart from other studies that may not provide concrete guidance for implementation.

Interdisciplinary perspective: This paper takes an interdisciplinary perspective, considering both the economic and environmental impacts of these systems, which is different from studies that may be focused on only one of these aspects.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The revised paper is suitable for publication in sustainability. 

Author Response

 Reviewer 1 comments: The revised paper is suitable for publication in sustainability.

 

Authors response; Thank you, Sir, for the insightful comments and valuable suggestions.

Author Response File: Author Response.docx

Reviewer 2 Report

1. Why should the cooling system with renewable energy use VCC rather than absorption equipment？ How does the logic of the article transition from ''3.6 The economic and environmental analysis of renewable energy-driven systems for cooling'' to ''4. Vapor Compression Chiller Integration into Thermal Energy Storage''?

2. Reviewer's comments need to be answered carefully. The author's response needs to be more detailed for better understanding. Some comments are missing, such as comment 3) in reviewer question 7 .

3. Please revise the article carefully again.  There are still many errors in the article format, such as paragraph and font format in section 3.6, Table 1 and 2.

Author Response

Reviewer’s questions

1. Why should the cooling system with renewable energy use VCC rather than absorption equipment？

Authors' response: This work attempt to put forward a review of the benefits (environmental and economic) of renewable energy-incorporated district cooling and integrated thermal energy storage with vapor compressor cooling for district cooling system. Therefore, the authors are not referring to the use of renewable energy systems with VCC for cooling systems. Rather, the work X-rayed the economic and environmental benefits of renewable energy-integrated, thermal energy storage coupled with VCC in comparison to the performance of district cooling systems alone based on economic and environmental impacts.

Reviewer question; How does the logic of the article transition from ''3.6 The economic and environmental analysis of renewable energy-driven systems for cooling'' to ''4. Vapor Compression Chiller Integration into Thermal Energy Storage''?

Authors response, to this question, the two subheadings are talking about different things. 3.6 is talking about the benefits of renewable energy-powered district cooling systems while section 4, discusses the benefits of integrating vapor compressor cooling/thermal energy storage integration into DCS. This has been corrected and therefore, hoped that this clarifies.

2. Reviewer's comments need to be answered carefully. The author's response needs to be more detailed for better understanding. Some comments are missing, such as comment 3) in reviewer question 7.

Authors' response; for this query, it can be seen that the title of the manuscript was changed from a review on the environmental and economic benefits of renewable energy integrated district cooling with thermal energy storage and vapor compressor cooling to a review on green cooling: exploring the benefits of sustainable energy-powered district cooling with thermal energy storage. Therefore, the duplication of renewable energy integrated DSC with thermal energy storage is in the title, and section 3 was removed.  

3. Please revise the article carefully again. There are still many errors in the article format, such as paragraph and font format in section 3.6, Tables 1 and 2.

Authors' response; The errors were significantly minimized and the Table 1 and 2 formats were harmonized.

 

Author Response File: Author Response.docx

Reviewer 3 Report

I believe the manuscript has been sufficiently improved.  

Author Response

 Reviewer 3 comments: I believe the manuscript has been sufficiently improved.  

 

Authors response; Thank you, Sir, for the insightful comments and valuable suggestions.

Author Response File: Author Response.docx

Round 3

Reviewer 2 Report

The authors addressed all my comments satisfactorily, and I believe the paper can be accepted for publication.