An Optimization Algorithm for Embedded Raspberry Pi Pico Controllers for Solar Tree Systems

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dr. Punitha et al. present an optimisation algorithm for orientation of a tree-like arrangement of solar panels, with the aims of reducing the required space for the installation and allowing maximum energy extraction. The article has potential, and the proposal is definitely interesting, but to warrant publication an extensive editing, rearranging, and updating is necessary. As it stands right now, the article is nearly incomprehensible, not only due to the level of English, which has to be improved, but also by its structure, lack of clarity, and overexplanations. I suggest the authors to look at their article critically, as if they did not know anything about it, and then try to write it again.

A few points where the authors might put some emphasis are: 

- The abstract contains lots of unstructured data, making it hardly informative. And, what is a 1200-angle displacement?

- It really is not necessary to explain in so thorough detail the Fibonacci series...

- Why are solar panels of 10 W chosen? And in general, why are the models chosen? Why the numbers? The choices must be explained for the research to be useful to different researchers.

- The algorithm explanation, several pages long, talking about horses, really breaks up the flow of the article. Please improve it and explain in terms of solar photovoltaic energy.

- How are the cases shown in results chosen, and why? How do they support the results and conclusions? Those are important questions whose answer cannot be easily found.

- I'll suggest that aesthetic judgement has no place in the article, as in line 560. Stick to facts.

 

Comments on the Quality of English Language

It really must be improved

Author Response

Reviewer comments and response of the authors:

A few points where the authors might put some emphasis are: 

Question 1: The abstract contains lots of unstructured data, making it hardly informative. In addition, what is a 1200-angle displacement?

Author Response: As per the reviewer suggestion, unstructured data and typographical mistakes are removed in the abstract section we have modified the abstract by incorporating all the suggestions.  We apologize for the typo error it is to bring it your notice that it is 120⁰ (degree) angle displacement and is corrected in the manuscript.

Question 2: It really is not necessary to explain in so thorough detail the Fibonacci series…

Author Response: As per the reviewer suggestion, the detail of the Fibonacci series sentence is removed the manuscript is updated.

Question 3: Why are solar panels of 10 W chosen? And in general, why are the models chosen? Why the numbers? The choices must be explained for the research to be useful to different researchers.

Author Response: Three panels are required for the development of a basic model of the phyllotaxy pattern to keep things simple. Firstly, employing three panels allows for the development of a basic model of the phyllotaxy pattern, which is essential for understanding how solar panels can be arranged efficiently in solar tree structures. Secondly, selecting panels with a modest power rating of 10 W each helps to keep the experimental setup manageable and cost-effective, especially for initial proof-of-concept studies. Thirdly, by using three panels, totaling 30 W, the research can demonstrate the feasibility of the proposed solar tree concept while still providing sufficient power output for practical applications as   per the reviewer suggestions the above information is included in the result section.

Question 4: The algorithm explanation, several pages long, talking about horses, really breaks up the flow of the article. Please improve it and explain in terms of solar photovoltaic energy.

      Author Response: As per the reviewer’s suggestions, some points of the general HHO algorithm is removed and HHO relevant to our application is included in section 2.3.1.

Question 5:How are the cases shown in the results chosen, and why? How do they support the results and conclusions? Those are important questions whose answer cannot be easily found.

Author Response: This study explores three distinct irradiation scenarios to comprehensively evaluate the performance of the proposed technique. Cases 1 and 2 represent uniform and non-uniform irradiation conditions, respectively, while Case 3 involves non-uniform irradiation with three distinct peaks.

In Case 1, where irradiation is uniform, a single identifiable peak is expected. This serves as a baseline for comparison and demonstrates the technique's ability to accurately identify the maximum power point (MPP) under ideal conditions.

 

In Case 2, with non-uniform irradiation, the technique's performance is further tested under more realistic scenarios. Here, the presence of multiple peaks challenges the algorithm to distinguish the global MPP from local maxima accurately. The ability of the suggested technique to accurately pinpoint the global MPP among local peaks demonstrates its robustness and applicability in practical settings.

 

Case 3 introduces a scenario with non-uniform irradiation featuring three distinct peaks. This represents a more complex situation commonly encountered in real-world environments. By successfully identifying the global MPP among multiple local peaks, the technique showcases its efficacy in optimizing solar energy extraction under diverse conditions.

 

In the first case, there is just one peak that is easily identifiable. However, in the second and third situations, the global maximum power was found in the first and third peaks, and the suggested technique accurately distinguished these values from other local peak values. This will strengthen the results of this work, and it is also included in the conclusion section.                      

Question 6: I'll suggest that aesthetic judgement has no place in the article, as in line 560. Stick to facts.

Author Response: Thank you for your suggestion. I respect your opinion, but we wish to bring to your notice that . Aesthetic judgement is not subjective, as it can be based on empirical evidence and criteria, such as visual appeal, usage, and creativity. The aesthetic appeal can be enhanced by applying attractive color paints and flower-like lighting on the solar tree. This may increase the solar tree's attraction to the public while also creating a pleasant ambiance in the surrounding region.

 

 

 

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The authors did some investigation and simulation for the solar tree system. This work can help to improve the performance of the solar tree. It can be accepted after the following issues are addressed.

1.     The spectrum of the light source should be provided. Is it AM 1.5G?

2.     The size of the PV modules should be provided.

3.     In Figure 10 and 20, some words at the top were hidden.

4.     The font of the words in some figures (such as Figure 8 and 9) is too small to recognize, please enlarge.

5.     In the introduction, some references should be cited when the authors introduced photovoltaic (PV) energy to help the readers understand the background knowledge: Advanced Science, 2016, 3 (7), 1500324; J. Semicond, 2022, 43(12): 122701; DeCarbon, 2024, 3, 100025; iEnergy, 2023, 2(3), 172-199.

6.     In Fig. 11-14 and 21-24, the caption for x and y axis should be provided.

7.     In table 4, the unit for Open circuit voltage should be V, not “VV”.

8.     In table 5, the unit for Optimum voltage should be V, not “v”.

Comments on the Quality of English Language

Quality of english language is good.

Author Response

Reviewer comments and response of the authors:

   Question 1: The spectrum of the light source should be provided. Is it AM 1.5G?

Author Response: Thank you for your Suggestion. The AM 1.5G spectrum represents the solar radiation at the Earth’s surface under clear sky conditions. In this study, 12W LED light is used who’s spectrum with wavelengths ranging from 380 nm to 940 nm and is included in the manuscript line number 575. 

 

 Question 2: The size of the PV modules should be provided.

Author Response: Thank you for your suggestion. The size of the three PV modules used in this study is 10 W and is specified in the result section

Question 3: In Figure 10 and 20, some words at the top were hidden.

Author Response: Thank you for your Observation. We apologize for the error as per the reviewers comment Fig. 10 and 20 hidden title is rewritten.

Question 4: The font of the words in some figures (such as Figure 8 and 9) is too small to recognize, please enlarge.

Author Response: Thank you for your Suggestion. As per the reviewer's suggestion, we have updated the font size, especially in Fig. 8 and 9 and we have verified the remaining figures.

 Question 5: In the introduction, some references should be cited when the authors introduced photovoltaic (PV) energy to help the readers understand the background knowledge: Advanced Science, 2016, 3 (7), 1500324; J. Semicond, 2022, 43(12):             122701; DeCarbon, 2024, 3, 100025; iEnergy, 2023, 2(3), 172-199.

Author Response: Thank you for your suggestions . We agree that citing and including above 4 references specified by reviewer on PV energy would help the readers understand the context and significance of our study. Therefore, we have revised the introduction section and added the following sentences with the suggested references:

PV energy conversion is based on the generation of electric current from light absorption by semiconductor materials. However, the efficiency and stability of PV devices are still limited by various factors, such as material defects,         environmental conditions, and device architectures [1-4].

Question 6: In Fig. 11-14 and 21-24, the caption for the x and y axis should be provided.

Author Response: As per the reviewer's suggestion, we have updated the figures by including the X and Y Axis from Fig. 11-14 and 21-24.

    

Question 7: In table 4, the unit for Open circuit voltage should be V, not “VV”.

Author Response: We apologize for the typo error, as per the suggestions we have updated the unit for open circuit voltage in the manuscript.

Question 8: In Table 5, the unit for Optimum voltage should be V, not “v”.

Author Response: As per the reviewers comment, the unit for Optimum voltage is corrected.

 

 

 

 

Author Response File: Author Response.doc

Reviewer 3 Report

Comments and Suggestions for Authors

The article presents a thorough investigation into the design, simulation, and hardware implementation of a solar panel system with a cascaded buck-boost converter. The writing pattern is clear and concise, making it easy for readers to follow the methodology and results presented. However, to further enhance the quality of the article, it would be beneficial to ensure consistency in terminology and formatting throughout the manuscript. Additionally, providing more detailed explanations and insights into the rationale behind certain design choices or simulation parameters could help readers better understand the research methodology and outcomes. By incorporating below comments, the paper can provide a more comprehensive analysis of the proposed solar panel system.

 1.     Provide more details about the simulation setup, such as the software used, simulation parameters, and any assumptions made.

2.     Incorporate an efficiency analysis of the proposed system to evaluate how effectively it converts solar energy into electrical power.

3.     Discuss the effectiveness of voltage regulation in the hardware setup. Provide insights into how well the cascaded buck-boost converter maintains stable output voltage levels under varying solar irradiation conditions.

4.     Discuss the efficiency of the cascaded buck-boost converter under different operating conditions. Analyze factors affecting converter efficiency, such as switching losses and component characteristics, and propose potential optimizations.

5.     Evaluate the performance of the Raspberry Pi Pico controller in generating PWM signals and controlling the buck-boost converter. Discuss any challenges faced during implementation and suggest improvements for better control accuracy.

6.     Perform a sensitivity analysis to evaluate the impact of parameter variations (e.g., solar panel characteristics, converter components) on system performance.

7.     Provide insights into the real-world application of the proposed solar panel system. Discuss potential deployment scenarios, such as off-grid installations or integration into existing power systems, and highlight the system's advantages in such contexts.

8.     Compare the proposed system with existing solar panel systems or MPPT algorithms. Highlight the unique features and advantages of the proposed approach, such as improved efficiency, better voltage regulation, or lower cost.

 

9.     Improve the quality of figures and diagrams to enhance readability and clarity. Use color coding, labels, and legends effectively to convey information intuitively. 

Comments on the Quality of English Language

minor check spellings are required

Author Response

Question 1:  Provide more details about the simulation setup, such as the software used, simulation parameters, and any assumptions made.

Author Response: As per the reviewer suggestion we have updated the article with a simulation setup ie. the software used is MATLAB and the simulation parameters are given in Fig. 8 and 9.

Question 2: Incorporate an efficiency analysis of the proposed system to evaluate how effectively it converts solar energy into electrical power.

Author Response: Thank you for your insightful suggestion. We agree that an efficiency analysis of our proposed MPPT technique is important to demonstrate its effectiveness and superiority. Therefore, we have added it in the results and discussion section and comparison Table 5 which is highlighted in yellow color. It is also included in the conclusion section also.

Question 3: Discuss the effectiveness of voltage regulation in the hardware setup. Provide insights into how well the cascaded buck-boost converter maintains stable output voltage levels under varying solar irradiation conditions.

Author Response: As per the reviewer's Suggestions, the optimum voltage provided by the proposed HHO algorithm is incorporated in Table 5. The cascaded buck-boost converter maintains stable output voltage levels are demonstrated in Table 3.

Question 4: Discuss the efficiency of the cascaded buck-boost converter under different operating conditions. Analyze factors affecting converter efficiency, such as switching losses and component characteristics, and propose potential optimizations.

Author Response: As per the reviewer suggestion, the efficiency of the converter is incorporated and a comparison is tabulated in Table 5. The cascaded buck-boost converter maintains stable output voltage levels are demonstrated in Table 3.

Question 5: Evaluate the performance of the Raspberry Pi Pico controller in generating PWM signals and controlling the buck-boost converter. Discuss any challenges faced during implementation and suggest improvements for better control accuracy.

Author Response : As per the reviewers comment, the performance of the Raspberry Pi Pico controller in generating PWM signals based on HHO provided duty cycle its GPIO pins used for the purpose and controlling the buck-boost converter is discussed and two different PWM signal is shown in Fig 26 a and b for evaluation purpose which is included in line number 560 onwards. In addition, for controlling the buck-boost controller, various input voltages, duty cycle from the Raspberry Pi Pico controller, and battery value as a load condition, 40 different buck and boost modes have been determined and summarized in Table 3. Table 2 shows the ripple current, ripple voltage, capacitor, and inductor used in the prototype development on cascaded converter’s boost and buck sides. The formula for developing a cascaded buck-boost converter is also thoroughly detailed in lines 482-509.

Question 6: Perform a sensitivity analysis to evaluate the impact of parameter variations (e.g., solar panel characteristics, converter components) on system performance.

Author Response: According to the reviewer suggestion, a sensitivity analysis is performed to assess the impact of parameter variations on solar panel characteristics using three different case studies, and converter components and design considerations are discussed in line 477 onwards, with values for the converter's parameters and values tabulated in Table 2 and 3.

Question 7 Provide insights into the real-world application of the proposed solar panel system. Discuss potential deployment scenarios, such as off-grid installations or integration into existing power systems, and highlight the system's advantages in such contexts.

Author Response : As per the reviewer  suggestion ,we have updated the article by including the  advantages of the solar PV Tree system is highlighted in the Introduction section line number 63 and 73. The real-world applications of the unique solar tree system include mounting several solar panels to a single pillar, resulting in a tree-like structure that uses sunlight to generate direct current (DC) from solar power. The tree structure enhances architectural look while also addressing land urbanization concerns. It may power streetlights, decreasing reliance on the grid; serve as charging stations for electric vehicles; and improve the visual attractiveness of outdoor settings, among other things. Off-grid installations enable solar trees to run independently and deliver dependable power even in remote locations.

Question 8: Compare the proposed system with existing solar panel systems or MPPT algorithms. Highlight the unique features and advantages of the proposed approach, such as improved efficiency, better voltage regulation, or lower cost.

Author Response:  As per the reviewer  suggestions, we have updated the article by including the proposed HHO algorithm in comparison in terms of optimum voltage and efficiency and is included in Table 5.

 Question 9  Improve the quality of figures and diagrams to enhance readability and clarity. Use color coding, labels, and legends effectively to convey information intuitively. 

Author Response: As per the reviewer's suggestion we have enhanced the readability and    clarity of    our figures and diagrams, we have used color coding, labels, and legends to highlight the key findings and explain the meaning of the data.

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have gone to great lengths to address my comments, substantially improving their article in the process. Therefore, I believe it is now suitable for publication.

Reviewer 3 Report

Comments and Suggestions for Authors

Author revised the manuscript properly and csn be accepted in present form.