Research on Reservoir Optimal Operation Based on Long-Term and Mid-Long-Term Nested Models

Round 1

Reviewer 1 Report

This paper deals with reservoir optimization by dovetailing long-term and mid-long term scheduling. In particular, it has been showed that a nested approach can improved the power generation as well as the reservoir management from a more general point of view. Despite the importance of the problem here faced and studied, I have major concerns about the novelties of the work. Could the authors provide a proper comment on this issue?

There are also some flaws in paper structure.

 

Here more detailed comments:

 

In my opinion, the introduction is not clear. The scope of the work is mixed with the tools utilized. If I understand correctly, the aim of the work is indeed to develop a nested optimization by taking advantage of long and mid term dovetailed scheduling. However, most of the literature review deals with optimization algorithms. Please, rewrite the introduction with a proper literature review regarded reservoir nested optimization. See for example “Shahryar Khalique Ahmad and Faisal Hossain, Forecast-informed hydropower optimization at long and short-time scales for a multiple dam network, Journal of Renewable and Sustainable Energy, 2020”. See also “Impact of the quality of hydrological forecasts on the management and revenue of hydroelectric reservoirs -- a conceptual approach, HESS”. In this framework please underline properly the points of novelty of the work.

 

The work hypothesis are not clear. In some part the author use “the typical years” in other the assessment analysis is performed year by year without any motivations.

 

Some definitions in the results discussion are not commented and have not link to the general assessment methodology descriptions.

 

Abstract lines 20-22 are not clear, could please reformulate them.

Line 42. I am not sue if “on the other hand” can be put at the end of one sentence.

I do not think that “abandoned” is the right collocation word for water in this context. What about “not exploited water”? Please check with a native speaker. Could also better specify what do you mean for abandoned water?

Line 177: The author have declared that “In this paper, the nesting of optimal scheduling is only done in flood season.” Could you please motive this choice?

Line 210: the authors refer to “Equations (3) ~ (7) are taken as constraint conditions of the objective function”. It is not clear whether they are using a multi-object optimizations of a single optimization nested. Please reformulate the mathematical description of the problem and its description.

Line 203. wrong formatting and not capital letter

Formula 8: this formula is not clear. Could the author introduce formula (8) more properly as well as give more details and literature references?

Line 284: The authors seems to introduce the consent of “error in runoff prediction”. Why here? What are the the hypothesis taken in this work in order to deal with run-off error and the assessment of the methodology?

the influence of different implementation modes on the operation of hydropower station

is analyzed”

Conclusion section. This section seems more a “discussion section” Please write proper discussion and conclusion sections.

Results and Discussion: could the authors show in a proper figure the comparison between power generation obtained by using the classical approach and presented one?

Could the authors compare in a proper scheme the three methodology here assess: Water level control mode, flow control mode, output control mode. Are these linked with the evaluation indexes?

Author Response

         Thank you for your serious and constructive comments on our manuscript. According to your suggestion, the manuscript has been revised. The revisions we have made can be seen in the attachment.  

Author Response File: Author Response.docx

Reviewer 2 Report

The paper addresses optimal reservoir operation based on long-term and mid-long term nested. The revision of the paper should address the following comments.

1. The case study should be better described. Information on installed powerhouse capacity should be given.
2. The purpose of the reservoir is not clear. Is it only power generation or also flood and draught protection?
3. The capacity storage in Table 1 should be defined in the text.
4. What is about the short-term operation of the reservoir. Is it influenced by the demand of the electricity market and its prizes?
5. Is firm energy and electricity supply safety not an issue?
6. Runoff forecast has high uncertainties. How is this considered in the in the presented approach? What is the confidence interval of the results?
7. In view of the uncertainties the results are given with an unreasonable precision (up to three digits for kWh and m3. The production results should be given in GWh with only tow digits. No digits should be used for the water volumes.

Author Response

          Thank you for your serious and constructive comments on our manuscript. According to your suggestion, the manuscript has been revised. The revisions we have made can be seen in the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors answered properly to all my requests. I have, however, still some suggestions. In particular, the novelties of the work have to be better underline. The literature review has been accurately expanded. This supports the key feature of the work: the adoption of a nested multi-object that deals with hydrological uncertainties and by considering different objectives. Although the nested approach has been already developed in the scientific community, it applications is still scarce as well as the quantification of uncertainties. These novelties could be added after line 120. I would suggest to add a list of the key element of this work as well.

Please add at line 117 the following references: “A Review of Optimization Algorithms in Solving Hydro Generation Scheduling Problems”, energies 2020; and Short-term hydropower optimization driven by innovative time-adapting econometric model, APEN 2020. These indeed provide some examples of standard optimization.

Please support the sentence “ As an important water supply source, the reservoir plays an important role in the utilization and allocation of water resources. Reservoir optimal scheduling is one of the important means to efficiently utilize water resources, improve flood utilization, and increase reservoir benefits.” with the following references examples:  Detailed simulation of storage hydropower systems in large Alpine watersheds, JOH, 2021; Determining dynamic water level control boundaries for a multi-reservoir system during flood seasons with considering channel storage. J Flood Risk Management. 2020; 

line 108: please cite “Impact of geology on seasonal hydrological predictability in alpine regions by a sensitivity analysis framework, water 2020” and “Benchmarking ensemble streamflow prediction skill in the UK”, HESS 2018 as examples of ESP applications. 

Author Response

Thank you for your serious and constructive comments on our manuscript. According to your suggestion, the manuscript has been revised. The revisions we have made can be found in the attachment.

Author Response File: Author Response.docx