Energy and Daylighting Performance of Kinetic Building-Integrated Photovoltaics (BIPV) Façade

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This paper investigates BIPV and kinetic facades in a case building. Through simulations, the author aims to compare energy and daylighting performance across different scenarios. While the research holds some significance, the paper lacks depth and novelty. It does not adequately justify the choice of building, and the simulations are too basic, covering only the general conditions of a single facade across different seasons. The contribution of the findings to existing knowledge is unclear. Therefore, I cannot recommend this paper. Here are some additional suggestions:

1 - Lines 68-133 contain an overly lengthy paragraph that includes various topics such as the benefits of daylighting, a literature review on BIPV envelopes/kinetic facades for energy savings, and the research aim. This results in a disorganized presentation, making it difficult for readers to find key information. It is advisable to split this content into several paragraphs and clearly articulate your research motivation and aim.

2 - Additionally, why does this paper focus on evaluating the energy and daylighting of an Australian commercial building? What is the significance and innovation of this research?

3 - Are the kinetic PV designs in Figures 4 and 6 original to this paper or based on existing research? Why were these particular designs selected? It is recommended to clarify the scientific basis for these choices.

4 - Sections 2.3.1-2.3.4, which describe the simulation step by step, are not well-structured. It is suggested to reorganize this section to present the key information more clearly and concisely.

5 - Moreover, key information about the case building, such as total area, shape coefficient and window-to-wall ratio, is missing. These factors also have significant impacts on energy performance.

6 - It is also recommended to quantitively specify the differences in the four scenarios discussed in the methods section.

7 - The results section’s simulation of daylighting, which covers only one wall, is too simplistic to accurately reflect the internal conditions of the entire building.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This work presents a thorough analysis of the feasibility and benefits of integrating photovoltaic (PV) solutions into building façades. The authors conducted a comprehensive study on a photovoltaic adaptive façade, evaluating its performance across various aspects, including daylighting, energy load, and energy generation. The methodology employed is clearly defined and well-documented in the corresponding section. However, despite the quality of the work presented, the manuscript cannot be published without addressing the following points:

1. Given the novelty of the manuscript in comparison to existing literature, the introduction would benefit from citing more recent studies on the integration of PV technologies into buildings, particularly ventilated façades (e.g., Energies 16(19), 6901, 10.3390/su15129146).

2. Please increase the font size of the figures, as they are currently difficult to read.

3. The labels in Figure 2 overlap with the page headline. Please correct this issue.

4. Lines 184-186 are bolded. Is this necessary?

5. Lines 238-240 state: "Fig. 4 demonstrates the tilting of kinetic panels according to the solar exposure on the façade during the morning, noon, and evening of different seasons throughout the year." However, Figure 4 only displays two configurations.

6. The sentence in line 241 is unclear. Please clarify.

7. Table 2 contains characters of different dimensions. Please standardize the character sizes.

8. Ensure consistent formatting across all tables.

9. According to the data presented in Figure 12, the introduction of the kinetic façade results in the highest levels of indoor lighting. How is this possible? The lighting levels should be lower compared to the "building without BIPV" configuration. Please analyze this point in greater depth.

10. There is a blank page in the manuscript, after which both page and row numbers restart. Please correct this formatting error.

11. Please provide a more detailed description of what is depicted in Figure 13.

12. Are you certain about the timeframe discussed in lines 76-78 of the Discussion section? The warranty for PV panels is typically 20 years. Please revise this statement accordingly.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript is a good read and will contribute significantly to the body of knowledge. The following comments should be addressed to enhance and improve the quality of the manuscript.

1. Referencing should be properly done and well in accordance with the prescribed style of the journal. For example, Jayathissa, et al. should be written as Jayathissa et al. without the comma. Similar issues in Line 85, 93, 109, 112, 116, 119 etc should be addressed.

2. The unnecessary punctuation in Line 134 should be removed.

3. Authors should provide the full description of (kWh) as indicated in Line 138 and HVAC in Line 152, PV in Line 151, VAV in Line 270, EPW in Line 284 and other parts where similar issues are found all across the manuscript.

4. Figure 2 need to be re-organised to fit into the paper template.

5. Line 184 to 186 contain bolded statements which are not pressing any idea or points from the manuscript. What is the significance of this part?

6. Figure 3 showing the case study building modeled using Rhino should be bordered on the sides and re-presented to show some form of context of the area/geographical location.

7. Table 1 should be re-organised as well to properly fit the contents.

8. The quality of Figure 4 should be enhanced to clearly show the numbers/values indicated within the Figure.

9. Table 4 is poorly presented and done. The authors need to address this and similar instances.

10. There are empty spaces and pages within the manuscript which should be addressed by the authors.

11. The conclusion and recommendation section requires some refining and concise inputs from the authors drawn from the results and findings of the study.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

This research demonstrates significant effort, yet several aspects require further clarification. Specifically, the study would benefit from a more detailed explanation of the research highlights and the identification of research gaps. It is also crucial to include a thorough comparison with similar studies in the field, analyzing the strengths and weaknesses of this work relative to others. I recommend a major revision of the article. Please carefully review my suggestions.

• The term "BIPV" in the title should be replaced with the full term “Building Integrated Photovoltaics (BIPV)” to enhance clarity and accessibility.

• Table 2: There are several blank spaces within the table. Please either provide explanations for these gaps or fill them with “/” if no data is available. Ensure consistency across the table to avoid confusion. Additionally, a similar issue is observed in Table 3, where a screenshot is used. Please replace this with a properly formatted table.

• Section 2.1 Case Study Building: The description of the institutional building parameters should be expanded. It should not only include the area but also provide details on the materials used, construction techniques, and any other relevant architectural and environmental factors.

• Section 2.2.1: The first paragraph should be presented in standard text format, not bolded, to maintain uniformity and readability.

• Figure 3: The purpose of Figure 3 is unclear. If the figure does not provide essential or useful information for the readers, it may be best to remove it. Please clarify its relevance or reconsider its inclusion.

• Efficiency of PV Panels: A more detailed explanation of the photovoltaic (PV) panels' efficiency, both in modeling and real-world application, is necessary. This should include a discussion of the materials used in the panels and their corresponding efficiency rates. The relationship between the modeled performance and actual performance should be clearly outlined.

• Formula 1 in Section 2.3.4 Energy Balance: It is unnecessary to dedicate an entire chapter to a single formula. This can be integrated into the broader discussion within the section to streamline the content.

• Blank Page Following Page 17: Please remove the blank page following page 17 to ensure a professional and polished presentation of the manuscript.

• Conclusion: The study mentions the implementation of a kinetic BIPV facade as a retrofit measure to enhance energy performance, daylighting, and renewable energy generation. However, the conclusions drawn from the study are not entirely convincing. Please provide a more descriptive analysis of the data to strengthen the argument and justify the conclusions.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 4 Report

Comments and Suggestions for Authors

Authors have revised accordingly.