Tilt Angle and Orientation Assessment of Photovoltaic Thermal (PVT) System for Sub-Saharan Tropical Regions: Case Study Douala, Cameroon

Round 1

Reviewer 1 Report

This paper evaluates an optimization model of tilt angle and orientation of a photovoltaic thermal system for Sub-Saharan Tropical Regions. The paper is focused and the objective has been achieved. The following suggestion should be incorporated before publication.

1.       Kindly add some more recent but relevant research papers on tilt angle and orientation of a photovoltaic thermal system for Sub-Saharan.

2.       It is suggested to add a separate section namely “Insights for practitioners and policy makers”. This section should describe the utilization of the results in a comprehensive and detail way for proposed regions.

 

Author Response

Journal                         Sustainability (ISSN 2071-1050)

Manuscript ID               sustainability-1947533

Type                             Article

Title                             TILT ANGLE AND ORIENTATION ASSESSMENT OF PHOTOVOLTAIC THERMAL (PVT) SYSTEM FOR SUB-SAHARAN TROPICAL REGIONS

Authors                        Aloys Martial EKOE A AKATA *, Donatien Njomo, Basant Agrawal,

                                    Auguste Mackpayen , Abdel-Hamid Mahamat Ali

Section                         Energy Sustainability

Special Issue                 Sustainable Energy Saving Building Envelopes

 

Reviewer comments and details Response to Reviewer comments:

Reviewer # 1:

This paper evaluates an optimization model of tilt angle and orientation of a photovoltaic thermal system for Sub-Saharan Tropical Regions. The paper is focused and the objective has been achieved. The following suggestion should be incorporated before publication.

1. Kindly add some more recent but relevant research papers on tilt angle and orientation of a photovoltaic thermal system for Sub-Saharan.

Some relevant research papers on tilt angle and orientation of photovoltaic thermal system for some Sub-Saharan countries have been added.

1. 3 of 18, L101 to 120

Lehloka et al. [13] investigated on empirical validation of the optimum tilt for PV modules in the Highveld of South Africa. They used Three fixed-axis PV modules installed at optimum tilt angles of Latitude -10°, Latitude, and Latitude +10° for they study. They recommended that PV modules should be mounted at Latitude minus 10° for the summertime period in the Highveld region of South Africa. Kokouvi [14] analyse the Effect of orientation and tilt angles of solar collectors on their performance in West and Central Africa. He concluded that the usual recommendation of orientation to the equator and tilt to latitude should not be understood as a requirement. Ashetehe et al. [15] used isotropic and anisotropic diffuse solar radiation models to developed a model in order to determine the seasonal and annual optimal tilt angle of the Photovoltaic module at any location in Ethiopia. The study showed that 5.11% to 6.275% (isotropic) and 5.72% to 6.346% (anisotropic models) solar radiation energy is lost when using the yearly average fixed optimal tilt angle as compared with the monthly optimal tilt angle. Obiwulu et al. [16] used an experimental approach to estimate the optimal monthly and yearly mean tilt angle in Lagos and 37 metropolitan cities in Nigeria. Six modules were mounted at different tilt angles with two modules north-facing, three south-facing, and one positioned horizontally to determine the orientation and tilt angle performance. The results were considerably appreciable concerning the magnitude of the values found in the literature, as well as the corresponding latitudes and global solar radiation recorded in those locations.

[13]      M. C. Lehloka, A. J. Swart, P. E. y Hertzog, Validating the optimum tilt angle for PV modules in the Highveld of South Africa for the Summer season, 3C Tecnología. Glosas de innovación aplicadas a la pyme. Edición Especial (2020) 137–157. http://doi.org/10.17993/3ctecno.2020.specialissue5.137-157.

[14]      E. N. Kokouvi, Effect of orientation and tilt angles of solar collectors on their performance: Analysis of the relevance of general recommendations in the West and Central African context, Scientific African 15 (2022) 2468–2276. https://doi.org/10.1016/j.sciaf.2021.e01069.

[15]      A. A. Ashetehe, B. B. Gessesse, F. Shewarega, Development of Optimal Tilt Angle Models of a Photovoltaic Module for Maximum Power Production: Ethiopia, Int. J. Photoenergy. (2022) ID. 8729570. https://doi.org/10.1155/2022/8729570.

[16]        A. U. Obiwulu, N. Erusiafe, M. A. Olopade, S. C. Nwokolo, Modeling and estimation of the optimal tilt angle, maximum incident solar radiation, and global radiation index of the photovoltaic system, Heliyon 8 (2022) e09598. https://doi.org/10.1016/j.heliyon.2022.e09598.

2. It is suggested to add a separate section namely “Insights for practitioners and policy makers”. This section should describe the utilization of the results in a comprehensive and detail way for proposed regions.

            Thanks for the suggestion, but the authors think that this section is not necessary.

 

Reviewer 2 Report

In the attached file.

Comments for author File: Comments.pdf

Author Response

Journal                         Sustainability (ISSN 2071-1050)

Manuscript ID               sustainability-1947533

Type                             Article

Title                             TILT ANGLE AND ORIENTATION ASSESSMENT OF PHOTOVOLTAIC THERMAL (PVT) SYSTEM FOR SUB-SAHARAN TROPICAL REGIONS

Authors                        Aloys Martial EKOE A AKATA *, Donatien Njomo, Basant Agrawal, Auguste Mackpayen, Abdel-Hamid Mahamat Ali

Section                         Energy Sustainability

Special Issue                 Sustainable Energy Saving Building Envelopes

 

Reviewer comments and details Response to Reviewer comments:

 

Reviewer # 2:

 

I found the subject studied appropriate and interesting. Its originality relies on investigation on both thermal and electric energy issues within one product: PVT modules. The paper is well written and organized. The scientific aim and methodology are clear and adequate. The results are precise and respond to the target of the paper. However, it seems they are applicable for the individual location. One can assume that other locations of Sub-Saharan Tropical Regions could feature different outcomes. For this reason, it is suggested to stress the fact in the title by adding “case study”. The limitation should be also mentioned in the main text.

 

P. 1 of 18, L3 to L4

 “… case study Douala, Cameroon.” added in the title

 

      The limitation mentioned in the main text.

P2 of 18, L62 to L80

Cameroon is a sub-Saharan African country bordered by Nigeria to the west, Chad to the northeast, Equatorial Guinea, Gabon and the Republic of Congo to the south and Central Africa to the east. It currently has a population of over 27 million, with a population growth rate of 2.6 percent. Like many other countries in the Sub-Saharan African region, Cameroon has many potential sources of renewable energy that are not fully exploited. Cameroon's solar potential is quite enormous. Average daily solar radiation ranges from about 4.5 kWh/m2/day in the south to about 5.7 kWh/m2/day in the north.  However, solar energy is not sufficiently well exploited. The government of Cameroon has the ambition to increase investments in photovoltaic electricity. Many solar projects have been implemented to increase the rate of access to electricity, public lighting as the Cameroon 2025 Photovoltaic Power Project PV. This project targets off-grid rural villages as well as underserved urban populations. The program plans to develop more than 500 MW of installed PV capacity throughout the country for a production of 750 GWh (about 1500 MWh/year for an installed capacity of 1 MW). However, the industry is facing a problem due to the lack of local technicians. Allowing for the fact that, the popularity of solar technologies grows, particularly the PV systems, the aims of the study is to prevent their indiscriminate use in construction sector and to encourage the use of photovoltaic electricity.

 

 

It is also recommended to add some explanation about the importance of tilt and angle (section 1.1.) in reference to the PV cells technologies (PV cells of 3d generation like perovskites, are not so much sensitive to tilt and angle like the silicon cells, including mono-crystalline cells to be the subject of the study).

 

     Some explanation about the tilt angle is found in the main text.

     Exemple: P. 2 of 18,  L82 to L93

 

 

 

Reviewer 3 Report

The topic is interesting to the relevant research field, however, the novel feature of the work is not clear showed. From this perspective, it needs major revision. The authors have conducted a brief work but some important things should be included in the revised manuscript.

1. The real applications and meaning of this study should be further elaborated in the section of Conclusion. It should only contain the significant outcomes and the take home message and novel findings of this manuscript.

2. Please read the paper carefully for English language style and accuracy, and make appropriate corrections and changes. With assist of professional experts rectify the grammatical and vocabulary error in the paper wherever necessary.

3. All abbreviations must be given full where first in use.

4. Some specific results should be given in the abstract.

5. What is the main aim of this study? It should be specified at the end of the introduction.

6. What exactly is the difference between this study and other studies in the literature? The answer to this question should be reflected in the study.

Author Response

Journal                         Sustainability (ISSN 2071-1050)

Manuscript ID               sustainability-1947533

Type                             Article

Title                             TILT ANGLE AND ORIENTATION ASSESSMENT OF PHOTOVOLTAIC THERMAL (PVT) SYSTEM FOR SUB-SAHARAN TROPICAL REGIONS

Authors                        Aloys Martial EKOE A AKATA *, Donatien Njomo, Basant Agrawal, Auguste Mackpayen, Abdel-Hamid Mahamat Ali

Section                         Energy Sustainability

Special Issue                 Sustainable Energy Saving Building Envelopes

 

Reviewer comments and details Response to Reviewer comments:

Reviewer # 3:

The topic is interesting to the relevant research field, however, the novel feature of the work is not clear showed. From this perspective, it needs major revision. The authors have conducted a brief work but some important things should be included in the revised manuscript.

1. The real applications and meaning of this study should be further elaborated in the section of Conclusion. It should only contain the significant outcomes and the take home message and novel findings of this manuscript.

Thank you for the suggestion, the author thinks that this suggestion has been made.

 

2. Please read the paper carefully for English language style and accuracy, and make appropriate corrections and changes. With assist of professional experts rectify the grammatical and vocabulary error in the paper wherever necessary.

The English language has been revised

 

3. All abbreviations must be given full where first in use.

Done

 

4. Some specific results should be given in the abstract.

Four (04) specific results have already been given in the abstract

P.1 of 18, L20 to L25

 

5. What is the main aim of this study? It should be specified at the end of the introduction.

            The main of this study have been specified in the introduction

P.2 of 18, L77 to L82

P.3 of 18, L152 to L156

 

6. What exactly is the difference between this study and other studies in the literature? The answer to this question should be reflected in the study.

The difference between this study and other studies has been added in the main text (introduction: P. 3 of 18, L152 to L156), particularly with studies conducted in the tropical Sub-Saharan region.

 

Round 2

Reviewer 3 Report

Accept in the present form.