Overall statement:

The paper presents an experimental investigation into the implementation of organic PCM (with a melting point of 30-32) for the thermal management of conventional monocrystalline photovoltaic modules (with a size of 50 W). The PCM material was filled in aluminum tubes which were attached to the back of the PV, with a layer of thermal grease to eliminate air gaps and improve heat transfer.

The strengths:

1) The study is comprehensive offering both electrical and thermal behaviours of the PV with and without PCM. 2) The problem statement is very relevant, and the introduction offers a well-prepared research background on the topic. 3) In the introduction the authors show the effect of PCM, and hence the importance of type, on PV surface temperature, and the type of PCM container. Although in most of the literature provided the container was rectangular, the authors of this study justified the problems with using rectangular container (weight, cost, suppression of natural convection, etc.). 4) The use of organic PCM was justified in the experimental setup and procedure section, refer to page 1520. 5) The experimental setup was explained in detail in the experimental setup and procedure section. 6) The results are well displayed, showing inputs and outputs to the system. 7) The element of comparison is well done, refer to table 3.

Weaknesses:

1. The authors should have presented literature on active cooling systems with PCM.
2. In figure 2, which shows the two tested PV modules, the thermocouples could have been placed more properly to cover less area of cells to avoid shading.
3. The measurements should have lasted longer to observe the effect of PCM discharge.
4. The paper is an experimental investigation, it would’ve been good to add the uncertainty analysis of the experiments.
5. The comparison in the section (a brief economic analysis) was made in terms of total costs “In comparison, the total cost of the current PV-PCM system is 55% lower.” however, it is preferable to compare the two systems based on cost of energy (COE).

Minor points:

1. In page 1518, in the sentence “… while inorganic PCM (RT20) with a melting …” I believe this is a typographical error, giving that RT20 is organic paraffin - PCM [1-2].

Recommendations for future work:

• To consider the impact of PCM charging and discharging on the performance of photovoltaic.
• To consider the impact of melting-solidification cycles on the performance of the PCM, and consequently, the performance of PV.
• To provide the fill factor and IV-curve characteristics of the PV with and without PCM.
• To consider nano-enhanced organic PCM for PV thermal management.

References:

[1] Hasan, A., McCormack, S. J., Huang, M. J., & Norton, B. (2014). Characterization of phase change materials for thermal control of photovoltaics using Differential Scanning Calorimetry and Temperature History Method. Energy Conversion and Management, 81, 322-329. [2] Goswami, D. Y., & Zhao, Y. (Eds.). (2009). Proceedings of ISES World Congress 2007 (Vol. 1-Vol. 5): Solar Energy and Human Settlement. Springer Science & Business Media.

• This is a post-publication review. The adherence to journal guidelines is not considered as the paper has already been processed by the editorial team of the journal