Analysis of Digital Twin Applications in Energy Efficiency: A Systematic Review

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Overall Evaluation

This paper presents a broad and relevant review of Digital Twins (DTs) for energy efficiency, covering their potential benefits, applications, and challenges. The topic aligns well with sustainability and Industry 4.0 trends, and the manuscript includes many references. However, the paper does not yet meet the standard of a rigorous systematic review due to methodological inconsistencies, lack of depth in critical analysis, and conceptual ambiguities.

The following major revisions are required before the paper is suitable for publication:

Major Issues Requiring Revision

1. Methodological Issues in Systematic Review Approach

Issue: The manuscript claims to be a "systematic review," but it does not adhere to established protocols such as PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses).

• The search methodology lacks clear documentation regarding:
• Exact search strings & Boolean operators used in IEEE Xplore, MDPI, Elsevier, etc.
• Synonyms, truncation, or controlled vocabulary (e.g., IEEE Thesaurus) were used.
• Justification for inclusion/exclusion criteria (e.g., why were studies over 10 years excluded?).
• Bias mitigation strategies (e.g., was article selection verified by multiple reviewers?).
• Figure 1 (Methodology Tree) is vague and does not effectively explain how articles were filtered and assessed.
• The quality assessment process is unclear. The paper mentions impact factors but does not use a standardised framework, such as the Cochrane Risk of Bias tool or Scopus journal quartiles.

Recommendation:

• Provide a PRISMA-style flowchart summarising the screening process.
• Include a table listing inclusion/exclusion criteria with clear justifications.
• Explain how study quality was assessed (e.g., journal quartile, number of citations, methodology strength).

2. Lack of Critical Analysis in Literature Review

Issue: The paper summarises a large number of sources but does not critically engage with them:

• There is little discussion of contradictory findings or research gaps.
• The paper does not clearly explain why some studies show different DT efficiency levels across industries.
• The review lacks a structured synthesis—it lists many DT applications but does not categorise them into meaningful themes.

Recommendation:

• Instead of listing studies individually, synthesise findings into key thematic categories, such as:
• Energy efficiency improvements (e.g., HVAC, smart grids, predictive maintenance).
• Industry-specific adoption barriers (e.g., real estate vs. manufacturing vs. utilities).
• Scalability & data security issues in large-scale DT deployment.
• Critically discuss methodological weaknesses in existing DT studies—which ones lacked real-world validation? Which ones relied too much on simulation-based assumptions?

3. Conceptual Clarity: Digital Twins vs. Related Technologies

Issue: The manuscript interchanges DT with BIM, IoT, and simulation models without clear distinctions.

• BIM is not inherently a Digital Twin—a BIM model is static, while a DT incorporates real-time sensor feedback and predictive analytics.
• The manuscript does not cite ISO 23247 (Digital Twin Framework for Manufacturing) or ISO 19650 (BIM Information Management).

Recommendation:

• Clearly define Digital Twins and their key components, distinguishing them from:
• BIM (Building Information Modelling).
• IoT-based monitoring systems.
• Computational simulations (which do not have real-time feedback loops).
• Reference official DT standardisation frameworks such as ISO 23247 & IFC standards.

 

4. Limited Discussion of Implementation Barriers

Issue: The paper focuses on DT benefits but minimises discussion of adoption barriers, including:

• High computational costs & energy demands for real-time data processing.
• Cybersecurity risks—DTs collect operational data, making them vulnerable to cyberattacks.
• Interoperability issues with legacy infrastructure in older buildings.

Recommendation:

• Dedicate a separate section to DT implementation challenges.
• Provide case study examples where DT adoption was unsuccessful or faced significant obstacles.
• Discuss emerging solutions (e.g., blockchain-based DT security, edge computing for scalable real-time processing).

5. Figures & Tables Need More Explanation

Issue:

• Several figures are not adequately integrated into the discussion (e.g., Figure 1 lacks a detailed explanation).
• Some tables are too text-heavy and challenging to interpret.

Recommendation:

• Improve Figure 1 by providing a step-by-step methodology breakdown.
• Convert large tables into summary tables with key insights rather than excessive text.

6. Language & Formatting Issues

Issue:

• Some sections contain grammatical errors and awkward phrasing.
• Repetitive content appears in multiple sections (e.g., DT advantages are restated several times).

Recommendation:

• A professional language edit is required to improve clarity.
• Remove redundant content and improve transitions between sections.

Final Recommendation

Reconsider after Major Revisions

Strengths:

• The manuscript addresses a highly relevant topic.
• It includes a wide range of references.
• The discussion on energy efficiency applications is well-structured.

Weaknesses that must be addressed:

• Methodological rigor is lacking—systematic review methods must be appropriately documented.
• The literature analysis is too descriptive—a more substantial critical synthesis is needed.
• DT concepts must be clearly defined to avoid confusion in BIM, IoT, and simulation.
• Discussion on implementation challenges must be expanded with real-world case studies.

Comments on the Quality of English Language

Language & Formatting Issues

Issue:

• Some sections contain grammatical errors and awkward phrasing.
• Repetitive content appears in multiple sections (e.g., DT advantages are restated several times).

Recommendation:

• A professional language edit is required to improve clarity.
• Remove redundant content and improve transitions between sections.

Author Response

The authors would like to sincerely thank the reviewers for their valuable comments and insightful suggestions, which have significantly contributed to improving the quality and clarity of our manuscript. All modifications have been carefully incorporated, with additions marked in blue for clarity and ease of review.

Reviewers 1

Reviewers 1	Responses
1-     Methodological Issues in Systematic Review Approach	The methodology has been reworked by adopting the prisma style.
2-     Lack of Critical Analysis in Literature Review	done
3-     Conceptual Clarity: Digital Twins vs. Related Technologies	A part has been added
4-     Limited Discussion of Implementation Barriers	A part has been added
5-     Figures & Tables Need More Explanation	Figures and tables are improved
6-     Language & Formatting Issues	The english was revised

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The article provides a comprehensive review of the impact of Digital Twins on energy efficiency and industrial sustainability, emphasizing their transformative potential.
 The case studies discussed provide concrete examples of how Digital Twins can optimize energy consumption and improve the performance of  industrial systems. This article also highlights the relevance and potential benefits of Digital Twins and provides a series of recommendations for improving energy efficiency and industrial sustainability. 

The work is well structured and the amount of information provided makes it a good tool to know the current state of the object of study.
Sometimes the presentation of the publications is a bit massive and rambling. But I sincerely believe that it is difficult to make a lighter presentation given the amount of information analyzed and presented in the work.
Some typographical errors should be corrected in the final edition. Therefore, I recommend the present work in its present state with only slight modifications in writing.

 

Comments on the Quality of English Language

Only slight modifications in the writing are necessary.

Author Response

The authors would like to sincerely thank the reviewers for their valuable comments and insightful suggestions, which have significantly contributed to improving the quality and clarity of our manuscript. All modifications have been carefully incorporated, with additions marked in blue for clarity and ease of review.

 

Reviewers 2

Thank you for your feedback. The article has been improved.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

Table 2 does not read well. Please consider reworking that table for better understanding.

Figure 3 has typos. “Sustanaible” and “Decarbonation”.

Section 3.4 has a lot of language on avoiding energy use in the energy sector or scheduling optimization. Generally, this doesn’t apply to energy efficiency, as stated in the title of the paper. I think this material is relevant to the topic, but the title of the paper may not be indicative of this point. For instance, lines 289-293 talk about energy use predictions and digitalization, which are great topics but may be out of the scope as it relates to the title of the paper.

Line 285 has an odd break. I’m not sure if content is missing there.

Section 3.6.1 has good information about construction but does the scope of the section include building commissioning? That could be an important section the seems to be left out of this section.

Table 5 would look a lot better if it wasn’t double-spaced. Right now, it is hard to read. Some of the references in this section appear to be more relevant to building operation than construction. A review of these references for inclusion in this section may be appropriate.

Again, in section 3.6.2, the text discredits applications of energy efficiency and elaborates on other aspects. This may necessitate a change in the title of the paper to change the focus away from energy efficiency.

Section 3.6.4 – what is the “energy efficiency sector”? I don’t know if that can be correctly compared to construction, mobility, and industrial sectors.

Line 382 – what is the “industrial transformation sector”? You might just mean “industrial sector” but it is not clear.

Line 392 – the text states “energy sector” but then the sentence goes on to mention production as if implying manufacturing. The cacophony of language here makes it difficult to understand what sector is actually being referenced.

Lines 400-417 are out of place and confusing. What are the questions here? Why are there bullet points? Why do the bullet points change halfway through. These lines need to be presented a different way for understanding.

Sections 3.7 and 3.8 need to be thoroughly revised. There is not flow in the sections. They are confusing and not well structured. There are no references in either of the sections, which is a major problem in a review paper. They seem like rough outlines and are very different than the rest of the paper up to this point.

Line 447 mentions “several studies” but no studies are referenced.

Line 154 cites the structure of digital twins but line 470 gives a different structure. It seems that these should be referenced in a similar section.

Section 3.9 title- Seems that “IA” is a typo.

Section 3.9 has little to no mention of energy use or energy efficiency. It doesn’t fit in the scope of the paper.

Sections 3.7, 3.8, and 3.9 are all poorly written and should all be completely rewritten. It is hard to follow what the authors are trying to show here.

Line 550 – typo

Line 554-548 need to be rewritten. It doesn’t read well.

Line 554 -576 – why does this section go into such detail on artificial furnaces? It seems very out of place and hard to follow. It needs to be rewritten.

Lines 583-589 are way too much detail into a topic that is way off the mark for this paper. This whole section should be completely rewritten or removed.

Line 604 – if energy is the focus of the paper, this needs to be the guiding principle throughout and other material not related to energy needs to be removed.

All of Section 4 is not written well. It seems like a bulleted list instead of a well-written analysis that synthesizes the findings from the review. The whole section should be rewritten as an article as opposed to bulleted notes on the topic.

Lines 740-741 – Overall, the paper doesn’t support this conclusion. There is not enough focus in the paper on energy efficiency and sustainability specifically. I feel that the paper goes off on tangents and doesn’t maintain a focused narrative throughout.  

The paper has a large number of typos and many unnecessary hyphens. These need to be corrected.

The first half of the paper reads much better than the second half.

Overall, the title of the paper might need to change, or the paper needs to be refocused on energy efficiency and sustainability. The paper seems to go off topic and doesn’t stay grounded in the central purpose of the paper.

Comments on the Quality of English Language

The second half of the paper needs to be thoroughly checked and clarified. It doesn't read as well as the first half. This would be from section 3.9 to the end. 

Author Response

The authors would like to sincerely thank the reviewers for their valuable comments and insightful suggestions, which have significantly contributed to improving the quality and clarity of our manuscript. All modifications have been carefully incorporated, with additions marked in blue for clarity and ease of review.

 

Reviewers 3

 

Reviewers 3	Responses
1-     Table 2 does not read well. Please consider reworking that table for better understanding.	Table 2 is reworked
2-     Figure 3 has typos. “Sustanaible” and “Decarbonation”.	It's corrected
3-     Section 3.4 has a lot of language on avoiding energy use in the energy sector or scheduling optimization. Generally, this doesn’t apply to energy efficiency, as stated in the title of the paper. I think this material is relevant to the topic, but the title of the paper may not be indicative of this point. For instance, lines 289-293 talk about energy use predictions and digitalization, which are great topics but may be out of the scope as it relates to the title of the paper.	some elements have been added to better reflect the article and title
4-     Line 285 has an odd break. I’m not sure if content is missing there.	It's corrected
5-     Section 3.6.1 has good information about construction but does the scope of the section include building commissioning? That could be an important section the seems to be left out of this section.	It includes the building commissioning.
6-     Table 5 would look a lot better if it wasn’t double-spaced. Right now, it is hard to read. Some of the references in this section appear to be more relevant to building operation than construction. A review of these references for inclusion in this section may be appropriate.	It’s improved
7-     Again, in section 3.6.2, the text discredits applications of energy efficiency and elaborates on other aspects. This may necessitate a change in the title of the paper to change the focus away from energy efficiency.	This section explores the use of digital twins in industry, highlighting that, in addition to their energy efficiency advantages, they are also crucial for saving time and reducing costs. The time savings lead to lower energy consumption than anticipated, aligning with the study's main objective: examining the role of digital twins in enhancing energy efficiency.
8-     Section 3.6.4 – what is the “energy efficiency sector”? I don’t know if that can be correctly compared to construction, mobility, and industrial sectors.	The title has been replaced by Energy applications across sectors, which better reflects the content
9-     Line 382 – what is the “industrial transformation sector”? You might just mean “industrial sector” but it is not clear.	you're right, it's been corrected
10- Line 392 – the text states “energy sector” but then the sentence goes on to mention production as if implying manufacturing. The cacophony of language here makes it difficult to understand what sector is actually being referenced.	the text has been reworded
11- Lines 400-417 are out of place and confusing. What are the questions here? Why are there bullet points? Why do the bullet points change halfway through. These lines need to be presented a different way for understanding.	It's corrected
12- Sections 3.7 and 3.8 need to be thoroughly revised. There is not flow in the sections. They are confusing and not well structured. There are no references in either of the sections, which is a major problem in a review paper. They seem like rough outlines and are very different than the rest of the paper up to this point.	These sections are summaries of what has been discussed in the previous part of the state of the art. They have been rewritten for greater fluidity and clarity.
13- Line 447 mentions “several studies” but no studies are referenced.	References are added
14- Line 154 cites the structure of digital twins but line 470 gives a different structure. It seems that these should be referenced in a similar section.	This part has been corrected
15- Section 3.9 title- Seems that “IA” is a typo.	It's corrected
16- Section 3.9 has little to no mention of energy use or energy efficiency. It doesn’t fit in the scope of the paper.	Thank you for your comment. We have modified the section title to "Interaction Between Digital Twins and Artificial Intelligence: General Applications" to better reflect its content, which demonstrates how these technologies optimize processes and contribute to reducing energy consumption.
17- Sections 3.7, 3.8, and 3.9 are all poorly written and should all be completely rewritten. It is hard to follow what the authors are trying to show here.	these sections have been rewritten
18- Line 550 – typo	It's corrected
19- Line 554-558 need to be rewritten. It doesn’t read well.	This section have been rewritten
20- Lines 583-589 are way too much detail into a topic that is way off the mark for this paper. This whole section should be completely rewritten or removed.	this part has been reworked
21- Line 604 – if energy is the focus of the paper, this needs to be the guiding principle throughout and other material not related to energy needs to be removed.	It's done
22- All of Section 4 is not written well. It seems like a bulleted list instead of a well-written analysis that synthesizes the findings from the review. The whole section should be rewritten as an article as opposed to bulleted notes on the topic.	This section has been rewritten

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

Most of my comments were sufficiently addressed. I still think there is an underwhelming number of citations in sections 3.7 and 3.8. Since it is a review paper, it seems there should be more references in that section supporting the ideas there.

Author Response

We thank the reviewer for their insightful comment. In response to the concern regarding the limited number of citations in Sections 3.7 and 3.8, we have revised these sections and added several relevant references to strengthen the scientific grounding of the discussion. These additions are highlighted in blue in the revised manuscript. We believe these references now provide a more comprehensive support to the ideas presented, in alignment with the expectations of a review paper.

Author Response File: Author Response.docx