Hydrogen vs. Battery in the Long-term Operation. A Comparative Between Energy Management Strategies for Hybrid Renewable Microgrids

Round 1

Reviewer 1 Report

Look at my all 25 comments and address them carefully. Check all references one more time.

Comments for author File: Comments.pdf

Author Response

Please see the attachment cover letter.

Author Response File: Author Response.pdf

Reviewer 2 Report

The authors present an interested manuscript with important experimental results. The manuscript is very insightful but needs improvement before acceptance. In particular :

a. The introduction even though it is informative it is presents very few details about the strategies in control of DERs in microgrids. It is propose that the authors should explain more the alternatives presented in their introduction, which will allow them to present more strongly their approach. To this point, the authors should include the findings of the following very recently published papers. The work presented in these manuscripts provide useful insights and approaches that this manuscript is not presenting very clear even though it should be in order to improve the comparison with the recent research work of others that improves every manuscript. These recent papers are:

1. C.N. Papadimitriou et al "Demand Response schemes in Energy Hubs: A comparison study", Energy Procedia, 157, 2019, p939-944,
   https://doi.org/10.1016/j.egypro.2018.11.260.
2. A.G. Anastasiadis et al "Maximum Power Photovoltaic Units Penetration under Voltage Constraints Criteria in Distribution Network Using Probabilistic Load Flow", Energy Procedia, 157, 2019, p578-585, https://doi.org/10.1016/j.egypro.2018.11.222.

b. Even though the authors present some explanations about 1 min of simulation corresponds to 1 hour of operation but, this is not justified. The authors should clearly justify this, as it is a critical part of their research.

c. There is an error analysis by mentioning only the values of errors in different points of the manuscript. They must present a comprehensive error analysis and not just a mentioning of the expected error, as their work is an experimental one and the evaluation of results and conclusions are always based on the expected error of the results.

d. The authors say that electrolyser is modelled empirically. This must be justified why the choose this and present more clearly this modelling along with the equations used.

e. In Fig 16 the figure caption seems to need a change as the authors present hydrogen hysteresis strategy and battery hysteresis strategy. (the word hysteresis is missing in the hydrogen strategy).

f. The comparison of the findings of the authors with the work of others is extremely small. The authors must present this comparison with details in order to justify the importance and the differences of their work, against the already published papers. This is of paramount importance for justifying acceptance.

Author Response

Please see the attachment cover letter.

Author Response File: Author Response.pdf

Reviewer 3 Report

1. The paper presents a study about “Hydrogen vs. Battery in the long-term operation. A comparative between Energy Management Strategies for hybrid renewable microgrids”. This topic is very relevant for a future perspective of smart grids. However, in some parts, it seems more a report than a scientific paper. For instance, how it can be useful for other researchers?
2. Please, clarify how the Res contributes to mentioned power quality problems (for instance, for current harmonics due to power electronics). It is expected that the power converters are controlled with sinusoidal grid current.
3. Figure 1 seems not clear. Please, clarify in the figure the meaning of the dashed lines.
4. The dc-dc (and others) converter was developed by the research team?
5. Figure 11b must be removed.
6. In figures 12 and 13 the tables cannot be above the figure. Please, correct it.
7. In figure 14, the variations are due to? For instance, at t=5h, why such sudden change in the battery voltage? This is real? It seems that happens a short-circuit.
8. In figure 19, the meaning of the negative powers is due to the charging/discharging process?
9. Please, clarify the meaning of the efficiency in table 4. What were the conditions for obtaining these values? This is very dependent of the charging/discharging process
10. Table 4a and 4b must be independent tables (4 and 5).

 

Author Response

Please see the attachment cover letter.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors have improve their manuscript, but still there are some minor but important points.

In particular:

1. Previous comment d. The authors should explain better this inside the manuscript. The response to the reviewer is quite clear but should become that clear inside the text.
2. Previous comment c. The authors must place this response inside the manuscript.

Author Response

Please see the attachment Cover letter to Reviewer 2 - round 2

Author Response File: Author Response.pdf