Evaluation of Site Suitability for Photovoltaic Power Plants in the Beijing–Tianjin–Hebei Region of China Using a Combined Weighting Method

Round 1

Reviewer 1 Report (Previous Reviewer 1)

Comments and Suggestions for Authors

The manuscript „Evaluation of Site Suitability for Photovoltaic Power Plants in the Bejing-Tianjin-Hebei Region of China Using a Combined Weighting Method” has been revised, taking into account the review recommendations, and the review comments have been summarised in a separate document. What I found confusing, however, was the fact that in track change mode, word-identical passages from the original version are also marked as changes. I think that the article can be further improved in the following respects:

1.     Introduction

The introduction section was expanded following the recommendations, but I still see opportunities for a more in-depth examination of the basic approach to the designation of suitable areas in the combination of negative approaches (exclusion of areas on the basis of selected criteria) with positive approaches (areas that are in principle suitable). It would also be desirable to deal explicitly with the topic of agri-photovoltaics at a suitable point, which is the dual use of PV installations over agricultural land that yields both power from the PV as well as agricultural products (fruits or crops).

2.     Materials and Methods

In the materials and methods section, further improvements could still be made in the presentation of the data, e.g. the new Table 2 Frequency statistics of evaluation indicators is not very attractive and easy to read in its current form.

The explanations in Table 3 on the indicators actually raise new questions if, for example, only cost aspects are considered under land suitability, which in this form should actually belong to the economic aspects.

3.     Discussion and conclusion

In the discussion section, I would prefer a more detailed discussion of the strengths and weaknesses of the chosen approach, in particular a discussion of the limitations with regard to aspects that cannot be covered by the methodology described (e.g. ecological and climate considerations).

Author Response

Thank you for your interest in our topic and taking the time and effort to comment on our manuscript. Your seriousness and the breadth and depth of thinking about problems are examples of our learning. The following sub-items and questions are answered one by one.

 

Reviewer 1:

 

The manuscript „Evaluation of Site Suitability for Photovoltaic Power Plants in the Bejing-Tianjin-Hebei Region of China Using a Combined Weighting Method” has been revised, taking into account the review recommendations, and the review comments have been summarised in a separate document. What I found confusing, however, was the fact that in track change mode, word-identical passages from the original version are also marked as changes. I think that the article can be further improved in the following respects:

 

Responses: 

 

Thank you very much for your reminder.In response to the mistake of repeated marks you raised, the reason for the problem is that the content of the article has been reordered, and we mistakenly believe that repeated marks can bring the reviewer reading convenience. We have corrected this misunderstanding in the latest modified version.

 

1. Introduction

 

The introduction section was expanded following the recommendations, but I still see opportunities for a more in-depth examination of the basic approach to the designation of suitable areas in the combination of negative approaches (exclusion of areas on the basis of selected criteria) with positive approaches (areas that are in principle suitable). It would also be desirable to deal explicitly with the topic of agri-photovoltaics at a suitable point, which is the dual use of PV installations over agricultural land that yields both power from the PV as well as agricultural products (fruits or crops).

 

Responses: 

 

Thank you for your suggestion.The introduction section delves deeper into the research methods that are appropriate for the region.  Additionally, we put forth a proposal regarding the feasibility of determining suitable areas for PV power plant construction on agricultural land.

 

The modifications are as follows:

 

Lines 73-84.

 

Depending on the chosen criteria, a simple spatial overlay method may overlook the varying degrees of influence of each factor in different regions, leading to an inaccurate assessment of boundary extent. However, relying solely on mathematical modeling or machine learning algorithms to evaluate the weight of influencing factors poses challenges such as data redundancy between indicators, complex calculation processes, high sample requirements and reduced accuracy. In this study, we adopt the horticultural forest frass and photovoltaic complementary space model[21–23] proposed by the Chinese government and develop a multi-level site suitability evaluation system based on factors such as urban density, solar radiation conditions, and vegetation coverage. To determine factor weights, we propose a comprehensive evaluation model named AHP-XGBoost-GIS that integrates the subjectivity of Analytic Hierarchy Process (AHP) with the objectivity of XGBoost.

 

Lines 98-100.

 

Furthermore, this research explores the applicability of the evaluation model across various land types and clarifies operational strategies for integrating parallel photovoltaic power generation with agricultural production on agricultural lands.

 

2.     Materials and Methods

 

In the materials and methods section, further improvements could still be made in the presentation of the data, e.g. the new Table 2 Frequency statistics of evaluation indicators is not very attractive and easy to read in its current form.

 

Responses:

 

Thank you for reminding.The contents in Table 2 have been reorganized and presented graphically to enhance readability for readers.

 

The modifications are as follows:

 

Lines 166-167.

 

 

Figure 2. Frequency statistics of evaluation indicators.

 

The explanations in Table 3 on the indicators actually raise new questions if, for example, only cost aspects are considered under land suitability, which in this form should actually belong to the economic aspects.

 

Responses: 

 

Thank you very much for your suggestions.Our concept of land suitability is further refined to distinguish it from economic suitability.

 

The modifications are as follows:

 

Line 175.

 

Table 2. Description of evaluation index system.

Target	Criterion	Indicator	Description of indicators
Site suitability of photovoltaic power plant	Ecological suitability	Terrain elevation sensitivity	Characterize the vertical zonality of the region. Additionally, elevation analysis can assist planners in identifying the most suitable areas for development.
		Terrain slope sensitivity	The slope is a vital indicator that reflects the undulating nature of the Earth's surface and plays a crucial role in classifying regional landforms and evaluating natural resources.
		Sensitivity of water source protection area	The presence of protected water sources and unfavorable hydrological conditions limit the placement of photovoltaic power plants.
		Vegetation cover sensitivity	Vegetation coverage reflects the extent of vegetation cover in a certain area, which is closely related to its ability to prevent soil erosion and reduce desertification.
		Surface temperature sensitivity	Photovoltaic cells show peak power generation in a specific temperature range, which directly affects the generation efficiency.
	Economic suitability	Solar radiation condition	The extent of photovoltaic resource abundance directly impacts the development capacity and operational efficiency of photovoltaics.
		Elasticity coefficient of electricity consumption	The elasticity coefficient of electricity consumption reflects the relationship between electricity consumption and national economic development. In this study, we simulate using nighttime lighting data.
		Urban density	Urban density reflects the level of regional urbanization, the closer to the city, the more conducive to reducing the cost of power consumption.
		Transport convenience	The distance from the road determines the convenience of photovoltaic farm construction and directly affects the construction cost.
	Land suitability	Sensitivity of agricultural land	By minimizing the spatial overlap between the electric field region and agricultural land, we ensure the safeguarding of agricultural productivity and preservation of farmers' rights.
		Sensitivity of residential land	The reduction of the overlap area between the electric field and residential land effectively mitigated local residents' resistance to power plant construction, ensuring smooth progress in project implementation.
		Sensitivity of  Special land	By minimizing the spatial overlap between the electric field region and the special land (including cultural landscape, military facilities, etc.) , potential constraints imposed by governmental policies can be circumvented, thereby facilitating unimpeded construction and operation of the power plant.

 

3.     Discussion and conclusion

 

In the discussion section, I would prefer a more detailed discussion of the strengths and weaknesses of the chosen approach, in particular a discussion of the limitations with regard to aspects that cannot be covered by the methodology described (e.g. ecological and climate considerations).

 

Responses：

 

Thank you for your advice.In the discussion part, we discussed the advantages of the methods used in this study, and further discussed the limitations of the current study.

 

The modifications are as follows:

 

Lines 459-470.

 

The selection of evaluation indicators in this study fully considers their applicability in the study area, and the quantification of index weights based on the combination method enhances the scientific and targeted nature of the final evaluation results. However, due to regional constraints and data sources, there is a lack of comprehensive consideration for ecological and climatic elements' impact on suitability. For instance, local rainfall can reduce photovoltaic panel power generation efficiency, mountain slope aspect can limit photovoltaic panel installation, and poor geological structure can affect engineering construction economics. The primary objective of photovoltaic is to decrease reliance on fossil fuels while providing greater economic and social benefits to users and investors.Therefore, future research should prioritize the incorporation of additional micro influencing factors into the evaluation indicators to enhance the comprehensiveness of the evaluation system.

Author Response File: Author Response.pdf

Reviewer 2 Report (Previous Reviewer 2)

Comments and Suggestions for Authors

The paper is now publishable due to the extensive positive changes the authors made in the work. However, adding a new section of policy implications seems to be good for guiding renewables agencies in China. 

Comments on the Quality of English Language

 Minor editing of English language required

Author Response

Thank you for your interest in our topic and taking the time and effort to comment on our manuscript. Your seriousness and the breadth and depth of thinking about problems are examples of our learning. The questions and suggestions provided will be addressed comprehensively in the subsequent sections.

 

Reviewer 2:

 

The paper is now publishable due to the extensive positive changes the authors made in the work. However, adding a new section of policy implications seems to be good for guiding renewables agencies in China.

 

Responses: 

 

Thank you very much for your reminder. In the introduction, we have added a discussion of the methodological advantages and disadvantages of the study and a more in-depth discussion of the contribution of the study to science, as well as the contribution of the research results to energy institutions in China.

 

The modifications are as follows:

 

Lines 73-84.

 

Depending on the chosen criteria, a simple spatial overlay method may overlook the varying degrees of influence of each factor in different regions, leading to an inaccurate assessment of boundary extent. However, relying solely on mathematical modeling or machine learning algorithms to evaluate the weight of influencing factors poses challenges such as data redundancy between indicators, complex calculation processes, high sample requirements and reduced accuracy. In this study, we adopt the horticultural forest frass and photovoltaic complementary space model[21–23] proposed by the Chinese government and develop a multi-level site suitability evaluation system based on factors such as urban density, solar radiation conditions, and vegetation coverage. To determine factor weights, we propose a comprehensive evaluation model named AHP-XGBoost-GIS that integrates the subjectivity of Analytic Hierarchy Process (AHP) with the objectivity of XGBoost.

 

Lines 89-105.

 

The Beijing-Tianjin-Hebei region serves as the economic hub of northern China[24–27], and the establishment of photovoltaic power plants in this area presents an opportunity to reduce power transmission costs and mitigate greenhouse gas emissions[28].  As the scale of photovoltaic power plant construction expands, available land resources are gradually diminishing[29].  Consequently, investors seek to maximize their returns on investment by identifying the most suitable areas for construction[30–33].  This study aims to develop a suitability evaluation model that streamlines traditional location selection methods, reducing labor and time costs while enabling rapid preliminary assessments of potential photovoltaic power field locations within the study area.  Furthermore, this research explores the applicability of the evaluation model across various land types and clarifies operational strategies for integrating parallel photovoltaic power generation with agricultural production on agricultural lands.  Through these efforts, this study expands the range of suitable locations for mountainous areas' photovoltaic electric fields and enhances land potential. In summary, the research findings can offer decision-making assistance to investors, practical applications in domains such as mountainous and agricultural land, and technical support for renewable energy institutions to achieve enhanced production efficiency.

Reviewer 3 Report (Previous Reviewer 3)

Comments and Suggestions for Authors

The article Evaluation of Site Suitability for Photovoltaic Power Plants in the Beijing-Tianjin-Hebei Region of China Using a Combined Weighting Method, resubmitted for review, has been significantly supplemented. However, there is still no information on the hosing capacity and the technical condition of power lines and their availability. The summary should be completed, the barrack is for research purposes Similarly, the introduction still does not clearly define the purpose of the research It is worth emphasizing in the conclusions what is the contribution of this article to science, and whether the method can be applied to other areas.

Author Response

Thank you for your interest in our topic and taking the time and effort to comment on our manuscript. Your seriousness and the breadth and depth of thinking about problems are examples of our learning. The questions and suggestions provided will be addressed comprehensively in the subsequent sections.

 

Reviewer 3

 

The article Evaluation of Site Suitability for Photovoltaic Power Plants in the Beijing-Tianjin-Hebei Region  of  China  Using  a  Combined  Weighting  Method,  resubmitted  for  review,  has  been significantly supplemented. However, there is still no information on the hosing capacity and the technical condition of power lines and their availability. The summary should be completed, the barrack is for research purposes Similarly, the introduction still does not clearly define the purpose of the research It is worth emphasizing in the conclusions what is the contribution of this article to science, and whether the method can be applied to other areas.

 

Responses: 

 

Thank you very much for your reminder. In section 2.3.1 of the paper, we provide additional information on capacity, technical status of power lines, and their availability that were not addressed in the study(lines 155-165). It is important to note that my selection of indicators only considered the current applicability within the research area. Additionally, in the introduction section, we have incorporated a comprehensive analysis of the methodological strengths and limitations of this study, along with an extensive examination of its scientific significance as well as the practical implications for energy institutions in China(lines 89-105).

 

The modifications are as follows:

 

Lines 155-165.

 

The factors influencing the site selection process of photovoltaic plants are relatively intricate. Currently, the government is actively promoting the rapid construction of high-voltage outgoing channels in the study area, which has significantly reduced the impact of power route accessibility on the suitability of photovoltaic plants[45,46]. Simultaneously, the government encourages ground-based photovoltaic projects to be located in areas with available capacity, thereby exempting the need for energy storage facilities[47]. Consequently, this study extensively analyzed various factors suitable for constructing photovoltaic power stations[37,48–55], and ultimately determined the appropriate factors for the study area (Figure 2). The determination of suitability evaluation factors in this study was based on both their applicability to the study area and their frequency of use as evaluation indicators.

 

Lines 89-105.

 

The Beijing-Tianjin-Hebei region serves as the economic hub of northern China[24–27], and the establishment of photovoltaic power plants in this area presents an opportunity to reduce power transmission costs and mitigate greenhouse gas emissions[28].  As the scale of photovoltaic power plant construction expands, available land resources are gradually diminishing[29].  Consequently, investors seek to maximize their returns on investment by identifying the most suitable areas for construction[30–33].  This study aims to develop a suitability evaluation model that streamlines traditional location selection methods, reducing labor and time costs while enabling rapid preliminary assessments of potential photovoltaic power field locations within the study area.  Furthermore, this research explores the applicability of the evaluation model across various land types and clarifies operational strategies for integrating parallel photovoltaic power generation with agricultural production on agricultural lands.  Through these efforts, this study expands the range of suitable locations for mountainous areas' photovoltaic electric fields and enhances land potential. In summary, the research findings can offer decision-making assistance to investors, practical applications in domains such as mountainous and agricultural land, and technical support for renewable energy institutions to achieve enhanced production efficiency.

Reviewer 4 Report (Previous Reviewer 4)

Comments and Suggestions for Authors

This new version of the document is of higher scientific quality and many of the issues mentioned in the first revision have been revised.

Author Response

Thank you for your interest in our topic and taking the time and effort to comment on our manuscript. Your seriousness and the breadth and depth of thinking about problems are examples of our learning. The questions and suggestions provided will be addressed comprehensively in the subsequent sections.

 

Reviewer 4

 

This new version of the document is of higher scientific quality and many of the issues mentioned in the first revision have been revised.

 

Responses：

 

Thanks for your suggestions. We really appreciate reviewers’ insightful comments, which are very helpful! As suggested, we have incorporated these comments into the revised manuscript. Our major revisions are summarized as follow.

 

First, we revised the manuscript and marked it with tracking change (in response to all reviewers’ comments).

 

Additionally, we meticulously recreated all the graphics in the article to ensure consistency in font and format. At the same time, we also checked the possible spelling mistakes in the text.

 

Besides response to the major comments above, we also checked the possible spelling mistakes in the text.

 

The article has been thoroughly revised and all the changes have been duly marked.  For further details, please refer to our recently uploaded manuscript.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript „Evaluation of Site Suitability for Photovoltaic Power Plants in the Bejing-Tianjin-Hebei Region of China Using a Combined Weighting Method” deals with the identification of suitable areas for PV power plant sites. With a multi-level evaluation system and the combination of AHP-XGBoost-GIS an interesting approach is presented, which, however, in my opinion, can be further improved with regard to the points described below.

1.     Introduction

The introduction should also focus more on the different systems of assessment criteria for examining the suitability of potential sites for the installation of photovoltaic systems, e.g. exclusion criteria that rule out the use of a site for ground-mounted photovoltaics, conflict criteria that describe a potential conflict of use that could arise from the use of a site for photovoltaic installations.

2.     Materials and Methods

Against the background described above, the definition of the evaluation index system in particular should be explained in more detail in the materials and methods section. Table 2 and Figure 2 contain redundant information. With regard to the economic indicators, it should also be critically noted that costs are only taken into account in terms of proximity to the road network. from an energy-economic perspective, optimal locations are in the vicinity of substations, which means that the highest possible amounts of energy can be fed into the grid with the least possible effort.

For the sub-chapters on the individual methodological steps, a simple visualisation with a graphic representation in diagram form would contribute to easier comprehension and better understanding of the content, e.g. AHP steps in 2.3.1 or XGBoost in 2.3.3

In any case, the textual descriptions of scale values 7 and 9 should be differentiated in Table 3. The AHP description in section 2.3.2 should also explain how the values in Tables 4 and 6-8 were determined. Make sure that the wording matches exactly, e.g. land suitability index in Table 8 and indicator name in Table 2.

Further redundancies are caused by listing the weightings in tabular form and as formulae, which could be reduced to a more readable form (without duplication of the information).

The explanations in section 2.3.6 could be more detailed.

3.     Results and Analysis

The results are presented and analysed in section 3. please pay attention to the legibility of the maps, which could be displayed slightly larger. Figure 6 should also be dealt with in a separate paragraph.

The above-mentioned aspects of costs in connection with a possible grid expansion should also be addressed (e.g. lines 311-312).

For a better understanding of the region described, perhaps another map could serve to supplement the explanations in the second paragraph of section 3.2.1

The analysis chapter should be concluded with a separate section on the strengths and weaknesses of the proposed method. Particularly with regard to the AHP part, it should also be addressed that elaborate calculations obscure/suppress the fact that pair comparisons are generally based on subjective assessments ("gut decisions").

4.     Results and Analysis

Section 4 should be renamed in any case, perhaps conclusions, the limitations could then already be addressed in the section on strengths and weaknesses suggested above.

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript aims to conduct a multi-level evaluation system for a comprehensive evaluation model for assessing site suitability for the construction of photovoltaic power plants in the Beijing-Tianjin-Hebei region. It also proposes an AHP-XGBoost-GIS comprehensive evaluation model. The findings suggest 48,800 km2 (21.59% of the total area) for establishing photovoltaic power plants since they are suitable areas in the study region. However, the methodology and the findings as two contributions of the paper are not new and do not help any development in the field of site selection for renewable energy production systems. Moreover, there is no development in environmental indicators which are vital in site selection for photovoltaic power plants. In addition, the work faces the following challenges for the publication;

- The work has no specific contributions to the concurrent literature in terms of both technical methodology and results.

- The results of the study do not help to develop a scientific background in the site selection field.

- The manuscript failed to give deeper insights into site selection methods regarding renewable energy power plants on a regional scale with ecological and climate considerations.

Therefore, I feel that the manuscript is not suitable to be published in Land.

Comments on the Quality of English Language

Moderate editing of the English language required

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have taken up a very important topic. The article deals with the evaluation of site suitability for photovoltaic power plants in China as a case study Beijing-Tianjin-Hebei region. Authrs have developed a multi-level evaluation system and proposed an AHP-XGBoost-GIS comprehensive evaluation model for assessing site suitability in the chosen region. I evaluate the research methods used for the designation of areas for the location of photovoltaic power farms correctly.

There are objections to the general assumption for the construction of photovoltaic farms. There is a lack of information on which farms are concerned in view of the predicted power. The authors adopted three groups of factors: ecological, economic and land suitability.

In the reviewer's opinion, the most important factor is missing - information on the hosting capacity and information of the condition of power infrastructure in in the study area. Site conditions, paved road access and power infrastructure are the main factors determining the economic viability of a photovoltaic power farm. Unless the authors prove that these factors, especialyy hosting capacity do not matter in China

In table 4 , line 3 should be land suitability

 

Reviewer 4 Report

Comments and Suggestions for Authors

The research article "Evaluation of Site Suitability for Photovoltaic Power Plants in 2 the Beijing-Tianjin-Hebei Region of China Using a Combined 3 Weighting Method" addresses an issue of great importance today, helping to deepen the feasibility of the energy transition.

However, in my opinion, the document presents two levels of quality: maximum, from section 3 (Results and analysis), but improvable in terms of the introduction and section 2 of methods and case study.

The introduction does not state the main objective of the study, nor the specific objectives. Nor does it make direct reference to the contribution of this research to the scientific field, nor does it cite the limitations, which undoubtedly exist, and which are always an element of rigour in any analysis.

On the other hand, section 2 appears to be disorganised and unbalanced. In my opinion, the methodology should be analysed first, in detail, but perhaps more synthetically than it appears in the text. And highlighting the reasons why the proposed method is selected. It should not be forgotten that the scientific literature that appears in this section will serve as a reference when analysing the results in the following section. Once the methodological part has been completed, the case study should be explained, even adding a guide outline of how the proposed methodology has been applied. Surely all the information is already in the document, but a revision is necessary to specify and order the contents in section 2.