Effects of Coating Materials as a Cleaning Agent on the Performance of Poly-Crystal PV Panels

Round 1

Reviewer 1 Report

• Even though there is a practical interest in the research topic, a comparison of commercial solar panel coatings is not contributing to scientific understanding and evolution. This argument stands firm as long as the authors fail to link each material’s performance with the underlying anti-soiling or cleaning
• The authors present a poor understanding of the phenomena that are related to coatings effect on solar panels: photocatalytic coatings are hydrophilic - never hydrophobic (line 95-96), there is no reference to anti-reflective mechanism, no explicit reference to temperature coefficient of solar panels, not even the lamda/4 rule for optical coatings.
• The use of the English language is deplorable, and there are apparent typos that the authors did not even proofread. Sentences starting with a relative clause (line 40), excessive punctuation (line 82), missing punctuation (line 34, 53, 66, 68, 75), mistyping (line 56, 112,191) or even sentences that do not make sense (line 42, 72-73, 88) are to name a few of the problems that make the manuscript extremely hard to read. There are two cases that instead of the word “able”, the word “apple” has been used (line 185 and 331).
• Experimental setup is insufficient: The authors do not refer to the season temperature recording were obtained and if there was a normalization procedure among the reference and coated solar panels.Surface preparation and sample application is debatable: Figure 13 presents a surface full of streaks and misapplication patterns.

Author Response

Reviewer #1:

1. Even though there is a practical interest in the research topic, a comparison of commercial solar panel coatings is not contributing to scientific understanding and evolution. This argument stands firm as long as the authors fail to link each material’s performance with the underlying anti-soiling or cleaning.

Response: The revised manuscripts includes additional comments on the novelty of the current paper.

Response:  The literature review has shown that there are no commercially available cleaning materials that have been approved as easy to clean materials for solar panels. In order to achieve such a material that exists at low cost and high cleaning efficiency, a need for developing customized materials do exist. The development of customized materials starts from available easy to clean materials for glass to overcome drop of efficiency of solar panels due to heat and dust accumulation.

The objective from the current study is to improve the electrical efficiency of the photovoltaic cells. Therefore, the performance of poly crystalline silicon panels under different coating materials has been investigated experimentally. The cell surface has been coated with different types of easy to clean materials founded in the Jordanian local market and used as easy to clean materials for glass surfaces. The main cleaning materials and techniques that are compared in this study are: Crystal glass coating type AJJL-CSS jiajialy nano energy saving and anti UV solution, GIE, sodium hexa me-ta phosphate and NanoUltra. Furthermore, a new material (TGIE) was developed in-house based on mixing GIE material with TiO₂ nanoparticles to improve the dirt cleaning effect. Many cleaning techniques are used simultaneously to increase cleaning effectiveness by reducing dust accumulation, reversing ultraviolet radiation and reducing cell temperature. Results were reported in terms of cell temperature and volt-age output.

 

2. The authors present a poor understanding of the phenomena that are related to coatings effect on solar panels: photocatalytic coatings are hydrophilic - never hydrophobic (line 95-96), there is no reference to anti-reflective mechanism, no explicit reference to temperature coefficient of solar panels, not even the lamda/4 rule for optical coatings.

Response: earlier work by other researchers has covered these issues as reported by the revised manuscript. The following paragraph was added:

Coatings transmission losses have been experimentally investigated to reduce the path length [15]. Moreover, quantity of incident light reaching the solar cell module could be increased by incorporating anti-reflection and light-scattering patterns [15]. Pedersen et al. [16] showed over the 2-month period of test a loss in efficiency in the range of 0.2–0.3%. This number was estimated based on 1–2% transmission losses as estimated. Oh et al. [17-18] utilized silica-based antireflection and anti-soiling coatings for which about 2.56% increase was achieved on average because of the anti-reflection coating.

 

3. The use of the English language is deplorable, and there are apparent typos that the authors did not even proofread. Sentences starting with a relative clause (line 40), excessive punctuation (line 82), missing punctuation (line 34, 53, 66, 68, 75), mistyping (line 56, 112,191) or even sentences that do not make sense (line 42, 72-73, 88) are to name a few of the problems that make the manuscript extremely hard to read. There are two cases that instead of the word “able”, the word “apple” has been used (line 185 and 331).

Response: The manuscript has been revised and proofread to improve the readability.

 

4. Experimental setup is insufficient: The authors do not refer to the season temperature recording were obtained and if there was a normalization procedure among the reference and coated solar panels. Surface preparation and sample application is debatable: Figure 13 presents a surface full of streaks and misapplication patterns.

Response: Weather condition for each experiment day is described and ambient temperature is measured during that day as seen in temperature measurement results.

Response: No normalization for data is used except that each solar panels were tested without any coating materials and difference in measured temperature and voltage was used as constant difference value in all discussions

Response: For figure 12 streaks are from the manual method we used to coat the glass with. For that, in conclusion we recommend to used other coating technique or methods. However, we can see that coated material is transparent and clean after one day of implementing it.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

In this work the authors focused on investigation of the effect of different clean materials on performance of poly crystalline silicon panels by Coating the cell surface with different types of easy-to-clean materials founded in the local market. There is no scientific novelty to the experiment design, I don't think it brings any new ideas or input to the PV technology community. The whole experiment is simply picking a a few cleaners from the market and see which cleans the panel better. I don't think it qualifies as a research article at all.

Author Response

Reviewer #2:

1. In this work the authors focused on investigation of the effect of different clean materials on performance of poly crystalline silicon panels by Coating the cell surface with different types of easy-to-clean materials founded in the local market. There is no scientific novelty to the experiment design, I don't think it brings any new ideas or input to the PV technology community. The whole experiment is simply picking a a few cleaners from the market and see which cleans the panel better. I don't think it qualifies as a research article at all.

Response: The revised manuscripts includes additional comments on the novelty of the current paper.

Response:  The literature review has shown that there are no commercially available cleaning materials that have been approved as easy to clean materials for solar panels. In order to achieve such a material that exists at low cost and high cleaning efficiency, a need for developing customized materials do exist. The development of customized materials starts from available easy to clean materials for glass to overcome drop of efficiency of solar panels due to heat and dust accumulation.

The objective from the current study is to improve the electrical efficiency of the photovoltaic cells. Therefore, the performance of poly crystalline silicon panels under different coating materials has been investigated experimentally. The cell surface has been coated with different types of easy to clean materials founded in the Jordanian local market and used as easy to clean materials for glass surfaces. The main cleaning materials and techniques that are compared in this study are: Crystal glass coating type AJJL-CSS jiajialy nano energy saving and anti UV solution, GIE, sodium hexa me-ta phosphate and NanoUltra. Furthermore, a new material (TGIE) was developed in-house based on mixing GIE material with TiO₂ nanoparticles to improve the dirt cleaning effect. Many cleaning techniques are used simultaneously to increase cleaning effectiveness by reducing dust accumulation, reversing ultraviolet radiation and reducing cell temperature. Results were reported in terms of cell temperature and volt-age output.

 

Reviewer 3 Report

 

1. The authors need to show what GIE and TGIE terms means ?? !!!! to be recognized by readers
2. The words "Fouling" is used many times. This reptation is disturb the reader ……from time to time, so the authors can  use other description  
3. Fig 3 need to use dashed line to or color line recognize them. Same thing with fig 4. And Fig 9 . My suggestion is all figures need to re-presents by used color bright lines. and even can the author write small note on the above of line to be recognized easily.
4. I advise the authors to present the " 7 modules" descriptions with their photos in Figures in practical part to rich the reader previously with PV modules to be easy understand the results and discussion later.
5. Why the authors write mat ₀ , mat 1 , mat 2 , etc when did the comparison between their modules …. The authors should use the same "names" or abbreviation   that used  to describe the module as they did before the comparison
6. For the comparison that did in fig 21 the authors can do zoom in range 11.04 and 2.05  and,  for y- access the authors can select range between (30 -52) ^o this will  better express the differences  between their modules.
7. Finally the weather is changing from month to month …even from week to week . The authors need to write statement they did the measurements for the modules at sametime  or same week. To ensure the true coparison between all modules.    

Comments for author File: Comments.docx

Author Response

Reviewer #3:

1. The authors need to show what GIE and TGIE terms means ?? !!!! to be recognized by readers.

Response: The manuscript has been revised and proofread to improve the readability.

2. The words "Fouling" is used many times. This repetition is disturb the reader from time to time, so the authors can use other description.

Response: The manuscript has been revised and proofread. Other terms have been used wherever possible to replace the term “Fouling”.

3. Fig 3 need to use dashed line to or color line recognize them. Same thing with fig 4. And Fig 9 . My suggestion is all figures need to re-presents by used color bright lines. and even can the author write small note on the above of line to be recognized easily.

Response: The manuscript has been revised and the figures were modified to enhance the readability.

4. I advise the authors to present the " 7 modules" descriptions with their photos in Figures in practical part to rich the reader previously with PV modules to be easy understand the results and discussion later.

Response: Authors thank the reviewer for his advice. However, we tend to keep the current layout of the manuscript to maintain the original flow of information.

5. Why the authors write mat 0 , mat 1 , mat 2 , etc when did the comparison between their modules …. The authors should use the same "names" or abbreviation   that used  to describe the module as they did before the comparison.

Response: The manuscript has been revised and the figures were modified to enhance the readability.

6. For the comparison that did in fig 21 the authors can do zoom in range 11.04 and 2.05  and,  for y- access the authors can select range between (30 -52) o this will  better express the differences  between their modules.

Response: Authors highly appreciate the recommendation of the reviewer. However, the current range of data was kept to maintain consistency throughout the manuscript.

7. Finally the weather is changing from month to month …even from week to week. The authors need to write statement they did the measurements for the modules at same time or same week. To ensure the true comparison between all modules.

Response: Weather condition for each experiment day is described and ambient temperature is measured during that day as seen in temperature measurement results.

 

Reviewer 4 Report

The topic mentioned in this manuscript is potentially exciting and the manuscript contains some practical experiments, relating to the enhancing of PV panel efficiency by using nanomaterial coating as a cleaning agent. However, there are some major issues that should be addressed by the authors:

 

• with respect to Figures, Fig. 1 should be redrawn or might need to take a copyright permission from another publisher except for the MDPI, please check if it requires so.

 

• Please change all x-axis titles from "Time By Hour" into "Time (hr)", and also make all figures more clear.

 

• The "Abstract" and "Introduction" sections must be made much more impressive by highlighting your contributions. The contribution of the study should be explained simply and clearly.

 

• Please define all the abbreviations in the Abstract section and all manuscript: e.g. AJJL-CSS, GIE, TGIE, …… etc.

 

• Please check all references citation carefully, hence Ref. [5] is not cited.

 

• In the introduction section, you should add a much more impressive background paragraph on the importance of using nanomaterials in electrical applications and also the efficiency of PV panels by adding and citing the up-to-date references, 2021, (Recent Advances in Polymer Nanocomposites Based on Polyethylene, PVC nanocomposites for cable insulation with enhanced dielectric properties, Effect of functionalized TiO₂ nanoparticles on dielectric properties of PVC nanocomposites, Proposed ANFIS Based Approach for Fault Tracking, Detection, Clearing and Rearrangement for Photovoltaic System).

 

• where are the specifications of Crystal glass coating type AJJL-CSS, jiajialy nano energy saving & anti UV solution, GIE, TGIE, sodium hexa meta phosphate and NanoUltra, and nanoparticles materials?? (type, company, dimensions, …etc.)

 

• Please add a new text that describes the characterization process of these new nanomaterials used for cleaning the PV panels.

 

• The conclusion section should be rearranged. According to the topic of the paper, the authors may propose some interesting problems as future work about the second generation in nanotechnology.
  
  

Author Response

Reviewer #4:

The topic mentioned in this manuscript is potentially exciting and the manuscript contains some practical experiments, relating to the enhancing of PV panel efficiency by using nanomaterial coating as a cleaning agent. However, there are some major issues that should be addressed by the authors:

1. With respect to Figures, Fig. 1 should be redrawn or might need to take a copyright permission from another publisher except for the MDPI, please check if it requires so.

Response: The manuscript has been revised and the mentioned figure was removed.

 

2. Please change all x-axis titles from "Time By Hour" into "Time (hr)", and also make all figures more clear.

Response: The manuscript has been revised and the figures were modified to enhance the readability.

 

3. The "Abstract" and "Introduction" sections must be made much more impressive by highlighting your contributions. The contribution of the study should be explained simply and clearly.

Response: The manuscript has been revised and the reviewer comments were implemented.

 

4. Please define all the abbreviations in the Abstract section and all manuscript: e.g. AJJL-CSS, GIE, TGIE, …… etc.

Response: The manuscript has been revised and proofread to improve the readability.

 

5. Please check all references citation carefully, hence Ref. [5] is not cited.

Response: References have been updated, new references have been added and all have been cited.

 

6. In the introduction section, you should add a much more impressive background paragraph on the importance of using nanomaterials in electrical applications and also the efficiency of PV panels by adding and citing the up-to-date references, 2021, (Recent Advances in Polymer Nanocomposites Based on Polyethylene, PVC nanocomposites for cable insulation with enhanced dielectric properties, Effect of functionalized TiO2 nanoparticles on dielectric properties of PVC nanocomposites, Proposed ANFIS Based Approach for Fault Tracking, Detection, Clearing and Rearrangement for Photovoltaic System).

Response: The manuscript has been revised and proofread to improve the readability. Furthermore, references have been updated, new references have been added and all have been cited.

 

7. Where are the specifications of Crystal glass coating type AJJL-CSS, jiajialy nano energy saving & anti UV solution, GIE, TGIE, sodium hexa meta phosphate and NanoUltra, and nanoparticles materials?? (type, company, dimensions, …etc.).

Response: Descriptions of each materials main properties is found for each material in results. company names for some of them is not shown since we are not allowed to do commercial advertisements and we have to take a copyright permission from them.

 

8. Please add a new text that describes the characterization process of these new nanomaterials used for cleaning the PV panels.

Response: The revised manuscripts includes additional comments on the novelty of the current paper.

Response:  The literature review has shown that there are no commercially available cleaning materials that have been approved as easy to clean materials for solar panels. In order to achieve such a material that exists at low cost and high cleaning efficiency, a need for developing customized materials do exist. The development of customized materials starts from available easy to clean materials for glass to overcome drop of efficiency of solar panels due to heat and dust accumulation.

The objective from the current study is to improve the electrical efficiency of the photovoltaic cells. Therefore, the performance of poly crystalline silicon panels under different coating materials has been investigated experimentally. The cell surface has been coated with different types of easy to clean materials founded in the Jordanian local market and used as easy to clean materials for glass surfaces. The main cleaning materials and techniques that are compared in this study are: Crystal glass coating type AJJL-CSS jiajialy Nano energy saving and anti UV solution, GIE, sodium hexa meta phosphate and NanoUltra. Furthermore, a new material (TGIE) was developed in-house based on mixing GIE material with TiO₂ nanoparticles to improve the dirt cleaning effect. Many cleaning techniques are used simultaneously to increase cleaning effectiveness by reducing dust accumulation, reversing ultraviolet radiation and reducing cell temperature. Results were reported in terms of cell temperature and volt-age output.

 

9. The conclusion section should be rearranged. According to the topic of the paper, the authors may propose some interesting problems as future work about the second generation in nanotechnology.

Response: the future work section was removed for the revised manuscript.

 

Round 2

Reviewer 2 Report

The authors have explained and answered the reviewers' concerns, I think the revised version is qualified for publication.

Author Response

thanks

Reviewer 4 Report

Accept in present form

Author Response

thanks