Sustainability Performance Evaluation of Hybrid Energy System Using an Improved Fuzzy Synthetic Evaluation Approach

Round  1

Reviewer 1 Report

The idea beyond the paper is surely interesting because it addresses a very actual and important issue. However, the paper presents some important issues that must be addressed carefully, as detailed below:

- line 34-42, please enclose at least one reference for each of the cited examples;

- Table 1, project no. 5 and 6, please specify (approximatively at least) which are the energy sources in order to highlight the hybrid nature of those projects;

- line 171, please define C_t and C_o immediately after (3) and better explain the meaning of i_c;

- line 175, please define W_des,T immediately after (4);

- line 180, (4) may be misleading, namely summing the deviations of all the energy supply may lead to zero when positive and negative contributions compensate for each other; in this regard, a more suitable choice should be summing the absolute values of all the energy supply deviations in order to avoid that opposite deviations compensate to each other, wrongly resulting in high power supply reliability;

- line 181, the second expression of (6) seems wrong, namely P_E,C should be removed and “]dt” is missing;

- line 193, (7) is not clear as it seems that round brackets are missing, please check this;

- line 212, “m” should be “n” in (8);

- line 218, the meaning of “m” used in (9) is unclear as it should not be the amount of carbon dioxide (line 194); please replace this symbol with the right one and explain the meaning of (9) more in detail. In this regard, please check also the use of “m” on lines 247-248 as another symbol seems to have to be employed (for example, h) for avoiding misunderstandings;

- line 233, “i,j” should vary within “1..n”, while k should vary within “1..l”, please check this;

- line 252, (15) is not clear, please explain better its meaning and that of the vector ω_i;

- lines 260-264, definition no. 2 should be moved after line 270; in addition, its meaning should be explained better, especially that of the symbol µ;

- lines 286-300, the statements there reported are not clear and confused; please explain better how the algorithm works and avoid putting equations within the main text;

- lines 328-331, the genesis of those matrices is not clear; in particular, those reported on line 328 seem the “A” matrices computed in accordance with (8), but the genesis of the other ones is unknown;

- Fig. 5, the meaning of this figure must be explained clearly and extensively within the main text, by highlighting the meaning of each colour and number there reported;

- lines 343-349, the statements there reported are unclear, please explain better how the case study has been assessed and how achieving the corresponding numerical values there reported;

- lines 351-358, it is not clear why the proposed algorithm should be insensitive to weight variation as the HES assessment should depend on the weight given to each criterion;

- lines 368-373, the statements there reported refer to FSE results, but these do not seem to be enclosed in the paper; please, check this carefully.

Furthermore, minor improvements are required, as pointed out in the following:

- line 2, please remove “(HES)” from the paper title;

- lines 20-23, please move the sentences “The results show … is “Moderate”.” to the conclusion because the outcomes of the paper should not be disclosed in the abstract;

- line 24, please replace “superiority” with “superior” and specify which other method is used for the comparison (FSE); the same goes also on line 384;

- please add a full stop at the end of each figure caption;

- line 136, please define GAHP again on this line because it is the first time it is used in the paper (without considering the abstract);

- line 146, “group AHP” should be replaced with “GAHP” directly;

- line 158, please define the acronym LCOE;

- line 226, title of Table 3 is the same of Table 2, please fix this;

- please increase the resolution of Fig. 3;

- line 312, please specify where the industrial plant is/will be located;

- line 314, check the unit of average radiation intensity (W/m2?);

- Table 8, please enlarge the table in order to show all the numeric intervals in just one row;

- please fix the following typos: “kings” with “kinds” (line 31), “as” with “is” (line 47), “Fig X” with “Fig. 3” (line 270).

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

This paper tries to evaluate the sustainability performance of HES. Firstly, an evaluation criteria system is established based on literature review. After that, the group analytic hierarchy process (GAHP) technique is used to obtain the importance weights of these criteria. Later, the sustainability performance of HES is calculated through an improved fuzzy synthetic evaluation approach based on cloud model.

The strong point of this work is that the applicability and effectiveness of this approach is demonstrated by a real case study in Zhejiang province, China. Also, the work is well organized, especially sect. 2 with the classification of the evaluation criteria. Another strong point is the sensitivity analysis, which is very important in understanding the robustness of the evaluation.

I have some comments

1) Is Fig. 1 done by the authors? If not, the source should be given

2) Sometimes the text has a grey background. Would it be possible to remove it?

3) Sect. 1 seems very look and the authors might consider having it shorter

4) In Sect. 4, my suggestion is to represent the member functions in a figure.

5) The surname in ref. [32] are missing

6) The following references have used artificial intelligence methods to predict or optimize energy demand, and they might be relevant for citation

Forecasting District Heating Demand using Machine Learning Algorithms
Energy Procedia, Volume 149, September 2018, Pages 59-68
Etienne Saloux, José A. Candanedo

Proactive control for solar energy exploitation: A german high-inertia building case study
Applied Energy, Volume 155, 1 October 2015, Pages 409-420
Iakovos T. Michailidis, Simone Baldi, Martin F. Pichler, Elias B. Kosmatopoulos, Juan R. Santiago

A hybrid method of dynamic cooling and heating load forecasting for office buildings based on artificial intelligence and regression analysis
Energy and Buildings, Volume 174, 1 September 2018, Pages 293-308
Jing Zhao, Xiaojuan Liu

Author Response

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Reviewer 3 Report

Revision manuscript ID sustainability-430113

The paper delivers on the agenda set in its title, by developing a method for assessing the performance of hybrid energy system using improved fuzzy synthetic evaluation approach. The topic of this research paper may be of interest to the engineering community. However, the current paper needs a careful revision.

Please consult the following observations:

1.   The English writing level must be improved. There are several sentences that are ambiguous;

2.   Figures must have axis titles and if possible measure units;

3.   Abstract section: The abstract is too trivial. The most important quantitative results should be added to the abstract section.

4.   Introduction section: Please add a reference to table 1;

5.   Evaluation criteria system section:

§  Please insert the criteria matrix components to figure 2;

§  Please consult equation 4. What does W_grid,T and W_des,T represents?

6.    Methodology section:

§  Please consult equation 9. What does m represents?

§  Where is definition 1? The numbering starts from 2 apparently;

7.    An empirical study section:

§  In my opinion, this section is the central area of the paper and yet many details are missing;

§  Please extend the case study;

§  Please add to this section the pseudocode extract for each method (evaluation criteria system, GAHP and Fuzzy synthetic approach);

§  Please add some numerical values for the used parameters. In addition please the references;

8.    Conclusions section:

§  Please expand the conclusions. The conclusions are extremely trivial.

The above observations are intended to contribute to the improvement of the manuscript. It should be noted, however, that they have not exhausted all possible improvements to be made.

 Best regards,

Author Response

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Reviewer 4 Report

Please find the attached file.

Comments for author File: Comments.pdf

Author Response

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Round  2

Reviewer 1 Report

I am quite satisfied of the way in which the authors have addressed many of the issues I highlighted. However, some few but important points still need to be improved, as detailed below:

- lines 20-22, please move the sentence “The results show that the criteria “levelized cost of energy” is the most important criterion with a weight of 0.253, followed by “energy utilization rate” with a weight of 0.140.” to the conclusion because the outcomes of the paper should not be disclosed in the abstract;

- although (4) has been modify, it seems that results are the same; I was thus wondering if they have been updated for accounting for this modified relationship;

- line 268-270, please clarify the meaning of µ, especially which property it measures, and which are the relationships with x and T;

- Section 3.4 is still not very clear, please better explain how cloud model works by clarifying the example there reported; in this regard, please avoid putting equations within the main text for better clearness;

- lines 353-362, some further explanations on how to achieve Table 9 should be enclosed, as well as the meaning of the numbers it encloses.

Furthermore, the following minor changes should be introduced:

- line 157, C_o seems being the “cash outflow” rather than the “cash flow”, please fix this;

- line 183, round brackets are still missing in (7), please fix this;

- line 288, please remove “and” before “below figure”;

- line 293, please fix two typos (“aggrate” and “finnal”);

- line 309-311, it is not necessary to give exact location of the plant, but just the city near which it is or will be built;

- line 339, first and second matrix seems duplicate, please check which is the right one;

- line 344, please replace “inter” with “inner”;

- please add a full stop at the end of each figure caption.

Author Response

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Reviewer 3 Report

A major revision of this manuscript has been made. The authors have taken into account my observations. Their responses are satisfactory. Several paragraphs and sentences have been duly clarified. Clearly, the manuscript has been greatly improved.

Best regards!          

Author Response

Thanks for your valuable comment

Reviewer 4 Report

The authors have done quite well to address all the concerns and comments of reviewers. 

Thank you for putting the effort to revise the paper.

Author Response

Thanks for your good comment.

Round  3

Reviewer 1 Report

The authors have addressed successfully all the issues I highlighted. Just few minor improvements should be introduced, as detailed below:

- (5) should account for absolute values of supply deviations, as done for (4), in order to avoid that positive and negative deviations compensate for each other;

- please show the variable name on the x-axis of Fig. 4;

- line 288, replace “undetook" with “undertook;

- line 183, round brackets are still missing in (7), please fix this;

- line 330, first and second matrix come from the same expert (E3), so one of them should be removed.

Author Response

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