Conceptual Study and Development of an Autonomously Operating, Sailing Renewable Energy Conversion System
Round 1
Reviewer 1 Report
energies-1728209
Title: Conceptual Study and Development of an Autonomously Operating, Sailing Renewable Energy Conversion System
Authors: Christopher Rickert, Anurag Mohanan Thevar Parambil, and Mareike Leimeister
The authors proposed the use of sailing wind turbines operating autonomously in high seas to harvest energy. The corresponding energy conversion system is named the Sailing Renewable Energy Conversion (SailREC) System. The harvested energy was converted onboard to a renewable fuel which is then stored onboard and later transferred to shore or other destinations of use. The requirements of the basic subsystems of the SailREC System were identified and defined. Various operating possibilities were explored, including a comparison of different sailing strategies and fuels for storage. Also, existing ideas were briefly addressed, and an example concept was suggested as well. This paper also proposed that more detailed investigations are necessary to answer whether the development of such a sailing renewable energy conversion system is viable from an engineering, economic, and environmental point of view. The overall idea of this work is meaningful for explorations and development of future green and renewable energies. However, there are major points that need to be further clarified or addressed by the authors.
- The rough concept for a SailREC System as shown in Fig. 11 was designed for the case of wind blowing from the right front of the wind turbine. But in the real situation, the wind over the ocean is variable and the directions and the strength of the wind vary significantly with seasons. How do the authors consider this aspect?
- The energy conversion performance of the proposed SailREC System is suggested to be compared with other energy conversion technologies related to green ocean energy from different viewpoints such as the output power density, the energy conversion efficiency, and the cost.
- The structure of this paper is not well organized and the language in the manuscript also needs extensive polishing. For example,
1) The sections of Introduction and State of the Art should be reorganized into one part which plays a key role in leading to the main works of this paper.
2) The tense is not standardized appropriately and is inconsistent in the abstract.
3) CO2 and N2 (Line 316 and Line 321 on page 9) should be CO2 and N2. Lots of other similar typos should be carefully checked and corrected.
Generally, the idea and the innovation of this work are good enough. But the writing of this work is much more like a technical research report rather than a scientific paper. More in-depth efforts should be put into polishing the organization and the language to further improve the manuscript.
Author Response
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Reviewer 2 Report
The paper has no novelty and added no additional value to the science. The paper may be converted into a reviewal paper. The paper includes a lot of information but unfortunately, they are already available in the literature.
Author Response
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Reviewer 3 Report
This paper is divided into two parts autonomously operating and renewable energy conversion system for conceptual study. The content of the whole article is rich and compact, for researchers who want to focus on renewable energy, but in different fields, they can quickly obtain the knowledge they need. However, because of the rich and compact discussions, it is not easy to integrate reading and information. It is a bit like reading a manual.
- Because the discussion is a systemic problem, the research on individual key issues is not deep enough. For example, more researches are placed on 4MW wind turbines and energy conversion systems.
- In the part of Navi Group, although the purpose of each component is simply explained, there is no way to effectively guide readers to understand the interrelationships between them. In addition, there is a large degree in explaining the influence of wind. Although wind turbines are installed on floating bodies, a large part of the force is distributed on the sea surface. But in the open sea, in addition to the influence of wind, there will also be the influence of waves and currents. The natural forces of these oceans can also cause changes in the forces on floating bodies and wind turbines, further creating associated risks.
- As in the previous comment, three methods were used for evaluation in the section on different sailing strategies. Although the results of different methods were analyzed, the part of the marine natural forces was not fully considered.
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Further revisions are needed:
1. Line 342: “20.68 Kelvin” should be revised as “20.68 K”
2. Delete the frames over all the equations such as Equation 13 and Equation 16
3. Figure A5 should be presented in a more scientific way.
In addition to revisions above, further proofreading should be carefully conducted by the authors to improve the manuscript.
Author Response
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Reviewer 2 Report
I'd like to thank the authors for their clarifications.
The authors improve the presentation of the paper. The quality of the paper is improved as well.
It is good practise if the authors clarify in the introduction that part of the paper objectives is revirewing the exsiting/old work in order to compar it with the prpopsed model/intervention.
Author Response
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