Peer Review Report Optimum unit sizing of hybrid renewable energy system utilizing harmony search, Jaya and particle swarm optimization algorithms

After reviewing this article published in the Sustainable Cities and Society Journal, the research topic of this paper is not new. Several authors have written extensively on the comparison of different algorithms. The paper itself is reasonably written though and would recommend acceptance after the following revision: Remarks and recommendations: 1. The aim of this paper is clear and it sounds interesting to read, which the authors proposed utilizing the Harmony Search (HS), Jaya and particle swarm optimization algorithms for sizing an optimum design of a hybrid renewable energy system containing a set of the Wind-Photovoltaic-Biomass-Battery technologies with a goal of cost-effectively, efficiently, and reliably meeting customers’ electricity demands. The outcomes of the three algorithms are compared, and the one with the most techno-economic optimum unit sizing of the HRES was determined. Different configurations consisting of solar PV, biomass generators, wind turbines, and batteries are modeled, simulated and optimized to obtain a system combination that is most energy-efficient and cost-effective in the studied zone. The study demonstrated that the ideal system with the least cost and the best performance was that which consists of thirteen solar PV systems, four biomass systems, one wind turbine and battery banks. 2. The title of the research is well-matched and related to the work done. Also, appropriate key studies have been included in this research. 3. The abstract section is generally very good and contains the aims of work, the summary of work and contain some quantitative analysis of the simulation results. 4. The introduction was good, the references are well selected and related and furthermore they are recent and sufficient, but the authors have to list some of the references that used the same algorithms to achieve the same goals, the authors should enrich the literature review by including additional related works. The impact of hybrid renewable energy sources (HRES) and microgrids must be mentioned. I suggest to study and introduce more literature relating to the application of multi-criteria decision analysis tools for HRES integration. Also, the authors should explain why they chose HS, Jaya and PSO over algorithms. Emphasis should be made by pointing out the strengths and limitations of other “non-algorithmic-specific-parameter algorithms” that mentioned at end of introduction page 3.

1. In general, the writing of the paper is good, the format of the paper is not all compatible with the desired template of the journal. Figure 5 is unclear, a little distorted, and needs to be clearer and more accurate. Likewise with Figure 2.

2. The paper technically sound and certainly, the paper contributes to the body of knowledge but there is no novelty in this paper. The subject matter presented in a comprehensive manner.

3. From a scientific point of view, this paper presents like those available in the references. It is recommended for authors to add relative advantages and disadvantages to each algorithm proposed in this work, as well as a comparison with more standard algorithms is required.

4. The procedure/mechanism of Figure 3 & 4 is significantly unclear.
5. Redundancy: many redundant sentences are detected throughout the manuscript, e.g., (According to Bloomberg New Energy Finance, the global electricity demand is expected to reach approximately 38,700 TW-hours (TWh) by 2050, which is up from 25,000 TW h in 2017), etc.

6. Many parameters/variables are not clearly defined in the paper.

7. Most of the presented equations under (Section IV. ALGORITHMS) requires a better presentation. In addition, no need to repeat the obtained result in the Conclusion. The Conclusion Section should reflect concluding remarks of the paper without going through the paper’s details.

8. The formula for writing and numbers must be consistent in all research. The forme of some equations that differ in Figures and writing, as well as the word (where), came after equation 6 and 7 in a capital letter while it came after equation 13 in a small letter.

9. The statistical representation of the number of simulation runs should be done to confirm the stability of the algorithms. Since the focus of the journal is to compare optimality of the algorithms, stability in fault must be addressed.

10. In the Emissions Analysis section, the emissions calculation methodology and formulation should be included with references cited. Just the tabular and graphical representations are not enough for an academic journal.

11. The analyses, results, and conclusions in the manuscript were logical for the data used.

12. The topic subject of this paper may be somewhat matched with the topic of the Sustainable Cities and Society Journal.

13. Considering the mentioned issues, in fact, that the paper needs some improvements. Its suitability for publication is not in doubt if auditors benefit from feedback provided by auditors and reviewers. I recommend accepting the manuscript after making the required amendments.