Forecasting the Energy and Economic Benefits of Photovoltaic Technology in China’s Rural Areas

Round 1

Reviewer 1 Report

The study is well organized and developed in an articulated way, perhaps I would reduce the engineering part and give more space to the economic results obtainable with the development of solar radiation. Furthermore, the times of realization of the works are infinitely long. Other than that it is a decent paper, but I am not an alternative energy specialist.

Author Response

Thank you for your comments concerning our manuscript. Your comments for our manuscript are very helpful for us to improve this paper. Your affirmation of the value of our research makes us more confident to do this research better.

Reviewer 2 Report

Please, consider the topic: “ Forecast of the energy and economic benefits that photovoltaic power generation technology can achieve in China’s rural areas in the future. “ Is this forecast of benefits the best choice for topic? Could this be something like: Possibilities for…

Please, try to find some more max.5 year old references.

Please, give the results categorized more precisely. Under chapter 4.4. Social benefits there are given good information about possible benefits. You could highlight these benefits and even discuss about them in chapter Discussion.

18: 6.4 billion m²

51: MJ/m² (three times)

52: 50×〖10〗^18 KJ  ???

53: 2.4×〖10〗^4 ???

121,126, 130,132: MJ/m²

295: PFA should it be BFA ???

554: E_gird should it be E_grid ???

708: m²

Author Response

1. At present, rural photovoltaic construction has been carried out in China, so the title of the manuscript is reasonable with the theme of " Forecasting ". The title of the manuscript is revised. At present, the title has been modified to " Forecasting the energy and economic benefits of photovoltaic technology in China’s rural areas ".

2. More references within 5 years have been added:

11. Margolis, R.; Gagnon, P.; Melius, J.; Phillips, C.; Elmore, R., Using GIS-based methods and lidar data to estimate rooftop solar technical potential in US cities. Environ. Res. Lett. 2017, 12, (7), 11.
12. Mikovits, C.; Schauppenlehner, T.; Scherhaufer, P.; Schmidt, J.; Schmalzl, L.; Dworzak, V.; Hampl, N.; Sposato, R. G., A Spatially Highly Resolved Ground Mounted and Rooftop Potential Analysis for Photovoltaics in Austria. ISPRS Int. J. Geo-Inf. 2021, 10, (6), 15.
13. Fina, B.; Auer, H.; Friedl, W., Cost-optimal economic potential of shared rooftop PV in energy communities: Evidence from Austria. Renew. Energy 2020, 152, 217-228.
14. Senatla, M.; Bansal, R. C.; Naidoo, R.; Chiloane, L.; Mudau, U., Estimating the economic potential of PV rooftop systems in South Africa's residential sector: a tale of eight metropolitan cities. IET Renew. Power Gener. 2020, 14, (4), 506-514.

3. Chapter 4.4 is a supplement to the favorable conditions for the construction of distributed photovoltaic system in rural areas. This chapter mainly analyzes the support of national policies for rural photovoltaic construction. At the end of chapter 4.4, the benefits of these policies to the development of rural photovoltaic are emphasized.

4. The unit and symbol problems in the manuscript have been corrected. More references have been added to the manuscript.

Reviewer 3 Report

The work attempts to assess the potential for solar photovoltaic power generation on the roofs of residential buildings in rural areas of mainland China by analyzing the economic benefits of investing in the construction of distributed photovoltaic (PV) systems in various provinces.
It is true that it is a scientific approach, however, it is not understood to be very new, as it has been applied in a similar way in other cases. Therefore, it is necessary to delve into the novel aspects of the proposal and indicate how it would be applicable to other countries.
Regarding the title and abstract, something else could be synthesized to attract more potential readers. The summary and, consequently, the text should perhaps more strictly follow the classical structure of objectives, methodologies, results, discussion and conclusions.
On the other hand, although the methodology followed is explained at the end of the introduction, it is understood that it must be an independent section just after said introduction.
Regarding the factors used for the calculation carried out, which affect the results of the economic benefits, it is believed that there are others in addition to those mentioned. They must be indicated and explained why they have not been used.
Limitations, reliability analysis and a better definition of some aspects should be included, when appropriate, as well as further development of the new findings resulting from this article. Finally, it is considered that the references are somewhat scarce since there is evidence of the existence of other authors not mentioned who have carried out similar experiences.

Author Response

1. The scientific method of this study are not novel. The highlight of this study is the overall situation of the installed capacity and economic benefits of photovoltaic system in rural China. At present, many researches are rarely related to the overall situation of China's rural areas, and most of them only focus on the photovoltaic construction in some specific regions of China. In order to show this point, this revised manuscript has added a description of the research highlights in "1. Introduction"(line 98-101).

2. The title and abstract have been modified to highlight the characteristics of this study.

Title modified to " Forecasting the energy and economic benefits of photovoltaic technology in China’s rural areas ".

The revised results of the abstract are as follows:

In recent years, with the rapid development of China's economy, China's energy demand is also growing rapidly. Promoting and promoting the use of renewable energy in China has become an urgent need. This study evaluates the potential of solar photovoltaic power generation on the roofs of residential buildings in rural areas of mainland China and calculate the area that can be generated, in-stalled capacity and power generation, and conduct a comprehensive analysis of the economic benefits of investing in the construction of distributed photovoltaic (PV) systems in various provinces. The findings unveiled in this study indicate that China still has more than 6.4 billion m² of rural construction area available for installation of PV modules. If it is all used for solar power generation, its annual power generation can reach up to 1.55 times the electricity consumption of urban and rural residents in the whole society. Through comprehensive evaluation of energy efficiency and economic benefits, the Chinese mainland can be divided into three types of resource areas. The three types of resource areas have their own advantages and disadvantages. According to their own characteristics and advantages, we can reasonably formulate relevant policies to accelerate the development of rural photovoltaic industry.

3. “2. Methodology” is added after “1. Introduction” as a summary of the research methods. At the same time, the summary of the method in the introduction is deleted.

As follows:

2. Methodology

This research first analyzes the building types and converts the rural building area into the roof area. Then, the roof area is converted into the installation area of PV modules which can be used for power generation by considering the influencing factors such as the optimal installation angle, installation spacing, roof slope and sur-rounding environment. Then, according to the solar radiation data of different regions and the current PV module parameters and other data, calculate the solar power generation potential, that is, energy efficiency. Finally, calculate and analyze the economic benefits of the construction of distributed PV system in rural areas under the relevant policies and measures of China. An overview of the methods used in this study is shown in Figure 1.

4. In the revised manuscript, other factors affecting the economic results of rural roof photovoltaic system are added (line 520-523, 569-572), and the reasons why it is not used in this study are explained.

As follows:

The cost of other PV system components not mentioned in Table 2 (wires, control system and renovation costs, etc.) is not included in the cost analysis in this research.

At the same time, there are also the energy-saving benefits brought by the environmental changes after the installation of photovoltaic system to reduce the building load. However, this part of income is greatly affected by the climate, and its income is low and unstable. Therefore, this benefit is not considered in this research.

5. In the conclusion of this paper, the limitations and develop ability of this study have been supplemented.

As follows:

This study only calculated and analyzed the photovoltaic application prospects of rural building roofs in China, and lacked the analysis of photovoltaic power generation potential of rural abandoned land in China, which could not reflect the overall photovoltaic power generation potential of China. Therefore, further work could be done to forecast the energy and economic benefits of photovoltaic technology in China.

And more references within 5 years have been added:

10. Vardimon, R., Assessment of the potential for distributed photovoltaic electricity production in Israel. Renew. Energy 2011, 36, (2), 591-594.
11. Margolis, R.; Gagnon, P.; Melius, J.; Phillips, C.; Elmore, R., Using GIS-based methods and lidar data to estimate rooftop solar technical potential in US cities. Environ. Res. Lett. 2017, 12, (7), 11.
12. Mikovits, C.; Schauppenlehner, T.; Scherhaufer, P.; Schmidt, J.; Schmalzl, L.; Dworzak, V.; Hampl, N.; Sposato, R. G., A Spatially Highly Resolved Ground Mounted and Rooftop Potential Analysis for Photovoltaics in Austria. ISPRS Int. J. Geo-Inf. 2021, 10, (6), 15.
13. Fina, B.; Auer, H.; Friedl, W., Cost-optimal economic potential of shared rooftop PV in energy communities: Evidence from Austria. Renew. Energy 2020, 152, 217-228.
14. Senatla, M.; Bansal, R. C.; Naidoo, R.; Chiloane, L.; Mudau, U., Estimating the economic potential of PV rooftop systems in South Africa's residential sector: a tale of eight metropolitan cities. IET Renew. Power Gener. 2020, 14, (4), 506-514.
15. Miranda, R. F. C.; Szklo, A.; Schaeffer, R., Technical-economic potential of PV systems on Brazilian rooftops. Renew. Energy 2015, 75, 694-713.

Reviewer 4 Report

Thank you for the opportunity to review this manuscript. The topic undertaken in the article is interesting and certainly needs to be explored. Unfortunately, there are several shortcomings that should be considered in the revised version.

Comment 1: Title is too long. I propose to shorten it. For example: "Forecasting the energy and economic benefits of photovoltaic technology in rural areas".

Comment 2: Findings in the abstract are also a bit too long. Only the most important results, directly related to the aim of the paper, should be indicated.

Comment 3: As the title of the article is about forecasting, so I think this keyword should also be mentioned in the keywords.

Comment 4: Abbreviations used in the work should be explained. For example, what it means: " 〖10〗^ "

Comment 5: The aim of the work, and especially the research gap which is filled in this article should be clearly defined and distinguished. The reader should not have to search for it and guess what the aim of the work, and especially the research gap and novelty to literature, are.

Comment 6: The title of the article concerns energy and economic benefits. However, the reader does not know which part concerns the energy benefits. I am not saying that it is not there, but reading the article it is difficult to guess where the energy benefits are calculated.

Comment 7: References should be internationalised. Firstly, there are few references and secondly, almost only Chinese authors. And yet the subject of photovoltaic technology is very common in the world literature and widely covered.

Comment 8: The 'conclusions' section needs to be improved. The main conclusions should be indicated here, whether the obtained results are in accordance with the literature or not, what contribution to the literature was finally achieved, what are the research limitations.

Author Response

1: The title has been modified to “Forecasting the energy and economic benefits of photovoltaic technology in China’s rural areas”.

2: The paper abstract has been rewritten and reduced to the Findings. As follows:

In recent years, with the rapid development of China's economy, China's energy demand is also growing rapidly. Promoting and promoting the use of renewable energy in China has become an urgent need. This study evaluates the potential of solar photovoltaic power generation on the roofs of residential buildings in rural areas of mainland China and calculate the area that can be generated, in-stalled capacity and power generation, and conduct a comprehensive analysis of the economic benefits of investing in the construction of distributed photovoltaic (PV) systems in various provinces. The findings unveiled in this study indicate that China still has more than 6.4 billion m² of rural construction area available for installation of PV modules. If it is all used for solar power generation, its annual power generation can reach up to 1.55 times the electricity consumption of urban and rural residents in the whole society. Through comprehensive evaluation of energy efficiency and economic benefits, the Chinese mainland can be divided into three types of resource areas. The three types of resource areas have their own advantages and disadvantages. According to their own characteristics and advantages, we can reasonably formulate relevant policies to accelerate the development of rural photovoltaic industry.

3: The keyword "forecasting" has been added. And the keywords were rewritten. As follows:

Solar energy; Distributed PV system; Energy-saving benefits; Economic benefit; Rural areas of China; Forecasting;

4: "〖10〗^" is a text format error, such as “50×〖10〗^18” should be “50×10¹⁸”, the corresponding part of the paper is revised.

5: In "1. Introduction"(line 98-101), we have added a description of the work objectives of this paper, especially the research gaps filled in by this paper.

At present, there are few researches on the prediction and analysis of the overall construction of distributed photovoltaic system in China's rural areas, most of which are for a single city or region. Therefore, this paper calculates and analyzes the distributed photovoltaic system for the overall construction of rural areas in China. This research first analyzes the building types and converts the rural building area into the roof area. Then, the roof area is converted into the installation area of PV modules which can be used for power generation by considering the influencing factors such as the optimal installation angle, installation spacing, roof slope and sur-rounding environment. Then, according to the solar radiation data of different regions and the current PV module parameters and other data, calculate the solar power generation potential, that is, energy efficiency. Finally, calculate and analyze the economic benefits of the construction of distributed PV system in rural areas under the relevant policies and measures of China.

6: This paper mainly calculates the installed area and power generation capacity of photovoltaic in rural areas of China in "3. Calculation of PV module power generation area " and "4. The calculation of power generation ", so as to analyze and calculate the energy efficiency.

7: More international references have been added. However, the research object of this study is rural areas in China, and the research of Chinese authors is closer to the actual situation of rural areas in China, so the reference of Chinese authors is more.

More references within 5 years have been added:

10. Vardimon, R., Assessment of the potential for distributed photovoltaic electricity production in Israel. Renew. Energy 2011, 36, (2), 591-594.
11. Margolis, R.; Gagnon, P.; Melius, J.; Phillips, C.; Elmore, R., Using GIS-based methods and lidar data to estimate rooftop solar technical potential in US cities. Environ. Res. Lett. 2017, 12, (7), 11.
12. Mikovits, C.; Schauppenlehner, T.; Scherhaufer, P.; Schmidt, J.; Schmalzl, L.; Dworzak, V.; Hampl, N.; Sposato, R. G., A Spatially Highly Resolved Ground Mounted and Rooftop Potential Analysis for Photovoltaics in Austria. ISPRS Int. J. Geo-Inf. 2021, 10, (6), 15.
13. Fina, B.; Auer, H.; Friedl, W., Cost-optimal economic potential of shared rooftop PV in energy communities: Evidence from Austria. Renew. Energy 2020, 152, 217-228.
14. Senatla, M.; Bansal, R. C.; Naidoo, R.; Chiloane, L.; Mudau, U., Estimating the economic potential of PV rooftop systems in South Africa's residential sector: a tale of eight metropolitan cities. IET Renew. Power Gener. 2020, 14, (4), 506-514.
15. Miranda, R. F. C.; Szklo, A.; Schaeffer, R., Technical-economic potential of PV systems on Brazilian rooftops. Renew. Energy 2015, 75, 694-713.

8: The conclusion has been rewritten as follows:

This paper takes the rural residential buildings in mainland China as the research object, carries out the solar energy resource application potential evaluation and economic benefit analysis, and draws the following conclusions:

China's rural areas are rich in space resources for investment and installation of distributed photovoltaic system, and the annual power generated by photovoltaic system can bear the power load of rural areas. And the calculation results show that there are still more than 6.4 billion m2  of building roof area in rural areas that can be used for the investment and installation of distributed photovoltaic systems, if used rationally, the power generation will be able to reach 1.55 times the total power consumption in rural areas. The research also gives the photovoltaic installable resources in rural areas of China, which can provide some data support for China's future plan of " carbon neutrality".

Promoting the popularization of distributed photovoltaic systems in rural areas will not only bring energy benefits and alleviate environmental problems, but also bring certain economic benefits to rural farmers. Comprehensively considering economic and energy benefits, mainland China is divided into three types of resource areas, and each resource area should reasonably formulate relevant policies based on its own characteristics and advantages to promote the development of the photovoltaic industry in rural areas.

This study only calculated and analyzed the photovoltaic application prospects of rural building roofs in China, and lacked the analysis of photovoltaic power generation potential of rural abandoned land in China, which could not reflect the overall photovoltaic power generation potential of China. Therefore, further work could be done to forecast the energy and economic benefits of photovoltaic technology in China.

Round 2

Reviewer 4 Report

Thank you for the opportunity to review this article again. Undoubtedly the article has been much improved and it is now better written. However, I still have 2 comments.

Comment 1: I still do not see an arguable research gap. The authors have only written: "At present, there are few researches on the prediction and analysis of the overall construction of distributed PV system in China's rural areas, most of which are for a single city or region. Therefore, this paper calculates and analyzes the distributed PV system for the overall construction of rural areas in China" (p.3).

There should be an explanation of why the topics taken up by the authors are worth investigating.

Comment 2: Section 6 'Conclusion' needs refinement. It does not indicate at all whether a research gap has been filled or not, i.e. what is the novelty of this work. Furthermore, it is not indicated whether the results obtained in this study coincide with the literature or not (probably because the literature review is poor).

Author Response

1. China is committed to "peak carbon dioxide emissions" and " carbon neutrality" in the future. Photovoltaic is considered to be one of the main energy situations in the future. And the distributed photovoltaic system combined with building has many advantages, which is considered as one of the important technical solutions to achieve "peak carbon dioxide emissions" and " carbon neutrality" in the future. At present, China needs to calculate the installed capacity and power generation that can be achieved by building integrated distributed photovoltaic. In this way, the relevant institutions to develop policies to improve data support and help. Recently, a number of provinces in China have formulated the building roof photovoltaic installation plans of cities and counties[1-5]. The calculation of PV installed capacity in China's provinces in this study can provide assistance for the implementation of the plan.

2. In this paper, the purpose of photovoltaic related prediction is to serve the formulation of relevant policies, so as to predict the total amount of energy that distributed photovoltaic can provide in China's rural areas in the future. It can provide assistance for many provinces in China to formulate the building roof photovoltaic installation plans of cities and counties in the near future.

[1]           Notice! The National Energy Administration released the pilot scheme of distributed photovoltaic development on the roof of the whole county (city, district). https://mp.ofweek.com/solar/a656714976197 (2021. 06. 24),

[2]           11th province! Shanxi Province issued the policy of promoting distributed photovoltaic in the whole county! https://baijiahao.baidu.com/s?id=1703804914999411688&wfr=spider&for=pc (2021. 06. 28),

[3]           Hubei Provincial Development and Reform Commission. Notice of Hubei Energy Bureau on submitting the pilot scheme of roof distributed photovoltaic development for the whole county (city, district). http://fgw.hubei.gov.cn/fbjd/xxgkml/jgzn/wgdw/nyj/xnyhkzsnyc/tzgg/202106/t20210629_3618798.shtml (2021. 06. 29),

[4]           Notice of Fujian Provincial Development and Reform Commission on carrying out the pilot work of centralized promotion of household photovoltaic in the whole county. https://msolar.in-en.com/html/solar-2377381.shtml (2021. 06. 06),

[5]           Notice on submitting the pilot scheme of roof distributed photovoltaic development in the whole county (city, district) (Anhui). https://news.solarbe.com/202106/27/340661.html