The Potential Role of Ammonia as Marine Fuel—Based on Energy Systems Modeling and Multi-Criteria Decision Analysis

Round 1

Reviewer 1 Report

A list of acronyms would be appreciated.

The biggest problem with this study ( multi-criteria decision analysis) is that based on a long-term modeling methodology it is unlikely that it can be validated or that the predictions will be fulfilled. This does not stop it from being an excellent exercise, tough.

Improve table 3 since the sections are not clearly seen.

Add subscripts and superscripts (eg NOx, SO2, PM10 etc)

It is observed that changes in criteria can lead to modifications in the method. How is this influence avoided or verified?

Improve figure 4 and eliminate or reduce the size of the numbers that accompany the bars.

It is strange to show references in the conclusions of an article if this is not a review. The conclusions should be relative to the work itself, not to the work of other researchers.

I see too many conclusions and some aspects that appear in this section are also found in the discussion of results.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The paper is original, well structured and well documented.

The methodological approach is consolidated and carefully implemented.

The results are convincing and deeply analysed, though their graphical presentation  could be improved, particularly by:

• better integrating figure 1 and 2, somewhere overlap in contents;
• increase the graphical quality of figure 4.

The 4 tables in the appendix could be more effectively introduced in the paper or, under judgement of the authors, eliminated.

Author Response

Please see the attachment. 

Author Response File: Author Response.pdf

Reviewer 3 Report

Hansson et al. submitted an interesting paper entitled "The Potential Role of Ammonia as Marine Fuel Based on Energy Systems Modelling and Multi Criteria Decision Analysis"

In the study, a rigorous literarue survey on production, costs, environmental impact of ammonia have carried out to apply it to marine fuel. Based on the literature survey, a energy system modeing and cost analysis using GET model have also been made.

Topic itself is very interesting and timely.
Results are clearly given in a good manner.
However this paper looks like a summary report, not a scientific paper, therefore some improvement is required to be published in Energies.

1. Monte Carlo method seems to be used in the section 2.2.3, however there is no clear explanation of the method how it is employed in this paper. More detailed description is necessary.

2. With same reason as above, more detailed description on the Multi-criteria decision analysis is required.

3. More detailed explanation on the method and formula used in the calculation need to be addressed.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf