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Rooftop photovoltaics (RPVs) are crucial in achieving energy transition and climate goals, especially in cities with high building density and substantial energy consumption. Estimating RPV carbon mitigation potential at the city level of an entire large country is challenging given difficulties in assessing rooftop area. Here, using multi-source heterogeneous geospatial data and machine learning regression, we identify a total of 65,962 km2 rooftop area in 2020 for 354 Chinese cities, which represents 4 billion tons of carbon mitigation under ideal assumptions. Considering urban land expansion and power mix transformation, the potential remains at 3-4 billion tons in 2030, when China plans to reach its carbon peak. However, most cities have exploited less than 1% of their potential. We provide analysis of geographical endowment to better support future practice. Our study provides critical insights for targeted RPV development in China and can serve as a foundation for similar work in other countries. Potential rooftop photovoltaic in China affords 4 billion tons of carbon mitigation in 2020 under ideal assumptions, equal to 70% of China's carbon emissions from electricity and heat. Yet most cities have exploited the potential to a limited degree. [ABSTRACT FROM AUTHOR]

Roadside noise barriers (RNBs) are important urban infrastructures to ensure that cities remain liveable. However, the absence of accurate and large-scale geospatial data on RNBs has impeded the increasing progress of rational urban planning, sustainable cities, and healthy environments. To address this problem, this study creates a vectorized RNB dataset in China using street view imagery and a geospatial artificial intelligence framework. First, intensive sampling is performed on the road network of each city based on OpenStreetMap, which is used as the georeference for downloading 6×106 Baidu Street View (BSV) images. Furthermore, considering the prior geographic knowledge contained in street view images, convolutional neural networks incorporating image context information (IC-CNNs) based on an ensemble learning strategy are developed to detect RNBs from the BSV images. The RNB dataset presented by polylines is generated based on the identified RNB locations, with a total length of 2667.02 km in 222 cities. Last, the quality of the RNB dataset is evaluated from two perspectives, i.e., the detection accuracy and the completeness and positional accuracy. Specifically, based on a set of randomly selected samples containing 10 000 BSV images, four quantitative metrics are calculated, with an overall accuracy of 98.61 %, recall of 87.14 %, precision of 76.44 %, and F1 score of 81.44 %. A total length of 254.45 km of roads in different cities are manually surveyed using BSV images to evaluate the mileage deviation and overlap level between the generated and surveyed RNBs. The root mean squared error for the mileage deviation is 0.08 km, and the intersection over union for overlay level is 88.08 % ± 2.95 %. The evaluation results suggest that the generated RNB dataset is of high quality and can be applied as an accurate and reliable dataset for a variety of large-scale urban studies, such as estimating the regional solar photovoltaic potential, developing 3D urban models, and designing rational urban layouts. Besides that, the benchmark dataset of the labeled BSV images can also support more work on RNB detection, such as developing more advanced deep learning algorithms, fine-tuning the existing computer vision models, and analyzing geospatial scenes in BSV. The generated vectorized RNB dataset and the benchmark dataset of labeled BSV imagery are publicly available at https://doi.org/10.11888/Others.tpdc.271914 (Chen, 2021). [ABSTRACT FROM AUTHOR]

Reliable information on building rooftops is crucial for utilizing limited urban space effectively. In recent decades, the demand for accurate and up-to-date data on the areas of rooftops on a large-scale is increasing. However, obtaining these data is challenging due to the limited capability of conventional computer vision methods and the high cost of 3D modeling involving aerial photogrammetry. In this study, a geospatial artificial intelligence framework is presented to obtain data for rooftops using high-resolution open-access remote sensing imagery. This framework is used to generate vectorized data for rooftops in 90 cities in China. The data was validated on test samples of 180 km2 across different regions with spatial resolution, overall accuracy, and F1 score of 1 m, 97.95%, and 83.11%, respectively. In addition, the generated rooftop area conforms to the urban morphological characteristics and reflects urbanization level. These results demonstrate that the generated dataset can be used for data support and decision-making that can facilitate sustainable urban development effectively. Measurement(s) building rooftop area Technology Type(s) computational modeling technique Sample Characteristic - Environment city Sample Characteristic - Location China [ABSTRACT FROM AUTHOR]

As energy saving and emission reduction become a global action, the disparity in energy intensity between different regions is a new rising problem that stems a country's or region's energy‐saving potential. Here we collect China's provincial panel data (1995–2017) of primary and final energy consumption to evaluate China's unequal and polarized regional pattern in energy intensity, decompose the inequality index into contributing components, and investigate possible driving factors behind the unequal pattern both regionally and structurally, for the first time. The results show that China's interprovince disparities in energy intensity increase and are exacerbated by the enlarging disparities in energy intensity between the least developed and most developed regions of China. The causes for this phenomenon are as follows: (i) rather loose regulatory measures on mitigating coal consumption; (ii) inferior energy processing technology in areas specializing in energy‐intensive industries; (iii) increasing interregional energy fluxes embodied in trade; and (iv) separate jurisdictions at provincial administrative levels. These factors can synthetically result in unintended spillover to areas with inferior green technologies, suggesting an increasingly uneven distribution of energy‐intensive and carbon‐intensive industries and usage of clean energy. The results reveal the necessities of regional coordination and cooperation to achieve a green economy. Key Points: This study aims to explore the regional disparities in energy intensity and its driving factors both regionally and structurallyRegional disparities in energy intensities are enlarging, especially after China introduced more stringent energy conservation policyThe causes are ineffective regulatory measures, unbalanced technologies, interregional energy fluxes, and separate jurisdictions [ABSTRACT FROM AUTHOR]

Technology transfers through the Clean Development Mechanism (CDM) under the Kyoto Protocol is one of the most important catalysts in the cooperation between developed (Annex I) and developing (non-Annex I) countries for climate change mitigation. With the large-scale implementation of CDM projects in recent years, it is important to timely and comprehensively analyze the effectiveness of technology transfers in these implemented projects on the level of individual countries. In this context, China is of particular significance as it is the biggest host country of CDM projects in the world; 50% of total CDM projects implemented from 2007 to 2012 have issued Certified Emission Reductions (CERs) to 60% of all of the CDM projects. In this study, we evaluated the performance of technology transfers in an exclusive database of 754 CDM projects hosted by China between 2007 and 2012 with issued CERs since CERs were first issued in China. In addition, we developed a logistic regression approach using 11-variables that include a series of extended technology transfer-based indicators from the perspectives of project design, economic level, and technology capability that have not been studied in detail in the past. The results show that technology transfers are more likely to occur in large-sized projects with higher CER incomes, in projects with international participants, and in projects involving types such as HFC-23 reduction, fuel substitute, and N 2 O decomposition, in comparison to projects involving renewable energy. We observed that over 90% of the technology transfer projects only include importation of equipment or training to China. In our findings of the regression results, it shows that technology transfers occurred more often in regions with lower technology capabilities, less energy consumption, and a lower GDP growth rate. Supported by high local technology capability and the governmental strategy with independent innovation, the advantages of introducing technology from other countries are offset by local technology diffusion. In a market view, financial incentives hinder CDM host parties from introducing new equipment or trainings for the high marginal cost, unless the high marginal cost of technology transfer can be offset by a large CDM with a high CER income. Technology transfer is more income-driven than sustainability-driven at the present stage in China. In our analysis, the drive out effect between HFC-23 and renewable projects in CDM suggests China government to publish more effective incentives to attract more sustainable types of CDM projects with a higher level of technology innovation. The results are also discussed in the context of policy issues, which can be helpful for the decision makers when formulating future sustainable strategic plans and policy. [ABSTRACT FROM AUTHOR]

China is the second largest emitter of greenhouse gases (GHG) in the world, with potentially about two thirds of total Certified Emission Reductions (CERs) for Asia on the world carbon market (Gruetter, 2002). Since 68% of its primary energy is from coal, China's average energy intensity is 7.5 times higher than the EU and 4.3 times higher than the US (EU, 2003). Therefore, introducing advanced clean technologies and management to China represents opportunities for Annex I countries to obtain low-cost CERs through CDM projects, and access to one of the largest potential energy conservation markets in the world. CDM can provide a win-win solution for both China and Annex I countries, and the Chinese government considers that the introduction of CDM projects can bring advanced energy technologies and foreign investment to China, thereby helping China's sustainable economy and generating CERs. As energy efficiency is generally low and carbon intensity is high in both China's energy supply and demand sectors, numerous options exist for cost-effective energy conservation and GHG mitigation with CDM. This paper reviews current Chinese policies and administrative and institutional settings for CDM cooperation, and discusses existing policy, institutional and other barriers in the energy market by drawing on observations and experience from previous initiatives such as Cleaner Production and energy efficiency. Some options to remove these barriers are addressed. In order to make CDM projects feasible, China's government needs to promote awareness, streamline administrative systems, and be more active in building a competitive edge in the world carbon market. [ABSTRACT FROM AUTHOR]

Wood pellets are regarded as one of the substitutes for fossil fuels like coal and oil for heating and co-generation. Wood pellets are a successful example of market penetration of renewable energy in some countries in Europe, e.g., Sweden. An analysis process is proposed in this paper and used to conduct a techno-economic assessment of wood pellets production and applications in some areas in China with the consideration of technology transfer from Sweden by examining their market competitiveness with coal in these areas. Financial indices such as net present value (NPV), internal return rate (IRR) and year-to-positive cash flow are calculated to investigate the profitability of the technology transfer. Four locations of applications in China have been considered as case studies. The result indicates that in the market-only-based scenario, wood pellets production will not be profitable in all selected areas. New scenarios from the analysis process show that reducing investment and increasing the amount of bank loan will be helpful to increase the project's profitability in general; adding taxes on coal could be effective, but it depends on Chinese government's future efforts on climate change mitigation; carbon credits on wood pellets through the clean development mechanism (CDM) might make wood pellet projects profitable giving wood pellets a nich-market. The potential global environment benefits of CO2 emission reduction by using wood pellets to replace coal in a 7 MWth coal-fired industrial boiler with a thermal efficiency of 80% and 5000 hours of operation time are also presented. [ABSTRACT FROM AUTHOR]

Negative emission technologies driven by nature with less energy input, lower costs, and long carbon storage capacities are essential for meeting ambitious global carbon mitigation goals. This paper evaluates the carbon sequestration potential of bivalve shellfish farming because its sequestration process is driven by nature, and it is cost-effective and energy efficient. The carbon in shells and the carbon that enters sediments via bio-deposition are long-lived forms of carbon. Using China as a case study, a preliminary estimation suggests that the carbon sequestration efficiency and intensity of cultivated shellfishes are much higher than those of artificial forests. In China, approximately 6.23 Mt CO 2 -eq a−1 was fixed via net carbon sequestration during shellfish growth from 2015 to 2019. In addition, the farmed shellfishes provided 0.37 Mt of harvested protein, and approximately 37.39 Mt CO2-eq a-1 were reduced compared to the same amount of protein provided by beef, and thus, shellfish farming has the win-win benefits of carbon sequestration and high-quality food provision. More importantly, a total of 5.64 Gt CO 2 -eq, accounting for 17.63% of the total emissions in 2020, can be potentially sequestrated at the global scale under the world's largest farming area scenario. • A Negative Emission Technology via shellfish farming was introduced. • Carbon sequestration function and efficiency of shellfish farming were investigated. • Carbon sequestration potential for bivalve shellfish farming was evaluated globally. • Life cycle GHG emissions of shellfish farming in China was assessed. [ABSTRACT FROM AUTHOR]

Photovoltaic water pumping (PVWP) and wind power water pumping (WPWP) systems for irrigation represent innovative solutions for the restoration of degraded grassland and the conservation of farmland in remote areas of China. The present work systematically compares the technical and economic suitability of such systems, providing a general approach for the design and selection of the suitable technology for irrigation purposes. The model calculates the PVWP and WPWP systems sizes based on irrigation water requirement (IWR), solar irradiation and wind speed. Based on the lowest PVWP and WPWP systems components costs, WPWP systems can compete with PVWP systems only at high wind speed and low solar irradiation values. Nevertheless, taking into account the average specific costs both for PVWP and WPWP systems, it can be concluded that the most cost-effective solution for irrigation is site specific. According to the dynamic simulations, it has also been found that the PVWP systems present better performances in terms of matching between IWR and water supply compared to the WPWP systems. The mismatch between IWR and pumped water resulted in a reduction of crop yield. Therefore, the dynamic simulations of the crop yield are essential for economic assessment and technology selection. [ABSTRACT FROM AUTHOR]

Photovoltaic noise barriers (PVNBs) have the potential to contribute to sustainable urban development by increasing the supply of renewable energy to cities while decreasing traffic noise pollution. However, estimating the power generation of PVNBs at the city or national scale remains a challenge due to the complexities of the urban environment and the difficulties associated with collecting data on road noise barriers (RNBs) and radiation. This study used RNBs, 2.5-dimensional (2.5D) buildings, and hourly time resolution radiation data, to estimate the power generation of PVNBs in 52 of China's major cities. First, hourly building shadows were estimated for each day of the year, covering the period from sunrise to sunset, to identify areas of RNB that are shaded at any given time. Second, hourly clear-sky radiation data were collected and corrected using a radiation correction model to simulate real weather radiation. Finally, utilizing an inclined surface radiation estimation model, the photovoltaic (PV) potential both inside and outside RNBs affected by building shadows was assessed. Subsequently, the power generation of PVNB was estimated based on parameters of mainstream PV systems in the market. The results show that the RNB mileage in 52 selected cities represents 87.7% of China's total RNB mileage. Building shadows often result in a radiation loss of approximately 30% for RNBs reception. The installed capacity and annual power generation of PVNBs in all investigated cities are 2.04 GW and 690.74 GWh, respectively. This study estimates the comprehensive PV potential of potentially exploitable PVNBs in China, offering essential scientific insights to inform and facilitate the strategic development of PVNB projects at both the national and municipal levels. • A framework to assess the photovoltaic (PV) potential of noise barriers is developed. • Building shadows are considered when assessing the PV potential of photovoltaic noise barriers (PVNB). • The RNB mileage of each city is closely and positively related to the PV potential on RNBs. • The annual power generation of PVNBs in China's 52 cities was estimated. [ABSTRACT FROM AUTHOR]

This paper analyzes if solar photovoltaic technology is economically feasible enough to compete with coal-fired power in Chinese cities in the subsidy-free context. Considering this, this paper further investigates how profitable investing in solar PV projects is. This paper firstly analyzes to what degree local coal-fired power plants can be replaced by distributed solar power in 344 prefectural-level cities in China. Levelized Cost of Electricity of solar PV power and the local desulfurized coal benchmark price are used for simplified cost crossover math to identify the replacement risk of local coal-fired power plants. Four risk-levels and their corresponding cities are identified, i.e. deemed no cost-risk, potentially at cost-risk, at cost-risk, and substantially at cost-risk. As a whole, 85.17% of current coal-fired power plants from the investigated cities are under cost-risk. Levelized Profit of Electricity, Net Present Value, Internal Rate of Return, and Discounted Payback Period are calculated for each city, and grouped using K-means algorithm. The cities are clustered into four groups, i.e. high return, medium return, moderate return, and low return. The results show that 65.99% of all the cities could achieve a moderate or higher financial return. The cost-risk and investment profit results are mapped for a better understanding of the regional variation in China. • We use the cost crossover method to group 344 prefectural-level Chinese cities into four cost-risk levels. • We use the K-means clustering algorithm to group 344 prefectural-level Chinese cities into four investment-profit levels. • 85.17% of current coal-fired power plants from the investigated cities are generally under cost-risk. • 36.63% of them can be replaced by distributed solar PV projects. • Investing in 65.99% of the cities will achieve an IRR of higher than 8%, and a DPBP of less than 15 years. [ABSTRACT FROM AUTHOR]

Indoor air pollution resulting from volatile organic compounds (VOCs) is a significant health concern, especially formaldehyde. Therefore, predicting indoor formaldehyde concentration is essential for environmental control. In this research, the authors develop a thermal and wet coupling calculation model of porous fabric that considers the influence of different phases of wet components and the coupling effect of heat and humidity on formaldehyde migration. We propose a modified calculation method of the formaldehyde mass transfer characteristic parameters of fabric to obtain the diffusion coefficient D and partition coefficient K. The heat and humidity coupling model and formaldehyde mass transfer model of fabric are simultaneously solved, and the authors analyze the influence mechanism of fabric loading rate, fabric type, temperature, and humidity on indoor formaldehyde mass transfer characteristics. We study the variation trend of fabric formaldehyde mass transfer characteristics coefficient and the temporal and spatial distribution of indoor formaldehyde concentration. The theoretical model is applied to practical problems by pre-evaluating the indoor formaldehyde concentration of decorated residential buildings in typical climate areas of China before occupancy. The authors obtain the variation rule of indoor formaldehyde concentration of residential buildings under typical hot and humid climate conditions, building materials, furniture, and fabrics. To provide theoretical support for indoor environmental control and human health protection. [Display omitted] • The VOC mass transfer process and heat and moisture transfer process of fabric are considered in coupling. • The influence of different phases of wet components is considered on VOC migration. • A calculation method for fabric's VOC mass transfer characteristic parameters is proposed. • The influence mechanism of fabric loading rate, fabric type, temperature, and humidity on indoor VOC migration are analyzed. [ABSTRACT FROM AUTHOR]

Multi-energy industrial parks, composed of the district energy supply system and terminal industrial loads, are dominant energy consumers with over 50% occupation of total energy consumption. Considering the energy conversion in the district energy supply system and adjustment of production subtasks in terminal industrial loads, the industrial parks could provide considerable flexibility for utility multi-energy systems to deal with contingencies. However, industrial parks may have multiple uncertainties originating from the production subtasks' variability, distributed renewable energy's fluctuation, and random failures of equipment. These uncertainties could make the flexibility assessment of industrial parks unreliable, which may further exacerbate utility system risks. To address the problem, this paper innovatively proposes the concept of probabilistic integrated flexible regions and corresponding characterization approaches, which can effectively describe the credible multi-energy adjustment ability of industrial parks. First, the energy-material flows in the industrial park are modeled considering multiple uncertainties while subject to constraints such as operating limits of equipment, energy and material balancing, and production targets. Then, the modeling and calculation methods of probabilistic integrated flexible regions are given. These regions are labeled with certain probability requirements and visualized in the input multi-energy space. Using a real-world test system that produces air conditioning equipment in China, the results show that the proposed model can effectively reflect the probability characteristics of the integrated flexibility under multiple uncertainties. For this test system, the area of a highly credible integrated flexibility, represented by the probabilistic integrated flexible region with 99% probability, is about half of that obtained by the deterministic model. That is, half of the integrated flexibility evaluated by the deterministic method in the test system may not be practically utilized considering the impacts of uncertainties. Therefore, the proposed method could provide a credible and comprehensive evaluation of the multi-energy industrial park's flexibility considering multiple uncertainties. • Exploiting the multi-energy(integrated) flexibility of industrial parks • Describing the probability characteristics of the integrated flexibility • Uncertainties in industrial parks shrink their integrated flexibility • Facilitating the interaction between demand and utility side in energy systems [ABSTRACT FROM AUTHOR]

• Battery transport and logistics to increase renewable use and system flexibility. • Full train transport and carpooling to improve the economics of battery use. • Levelized cost of energy of battery transport & logistics is $0.045/kWh averagely. High share of variable renewable energy is challenging to the traditional power system technically and economically. This calls for a significant increase to the system flexibility, which might result in the costs associated with energy storage and costly upgrades to the traditional transmission and distribution system. This paper presents a multi-stage battery transportation and logistics optimization method to increase the renewable energy consumptions, economics, and mobilities of the battery utilization. A new approach is proposed in which the batteries are charged in the renewable power plants and transported back and forth by railways between the renewable power plants and cities. Based on the forecasts of battery supplies/demands, multiple optimization stages (full train transport and carpooling) are designed by the branch-and-bound algorithm and genetic algorithm respectively. The proposed battery transportation and logistics concept and model are performed using the Beijing-Tianjin-Hebei region in China as an example. The results show that the levelized cost of energy of the battery transportation and logistics model is $0.045/kWh averagely. Also, by the use of mobilized batteries, the proposed battery transportation and logistics model increases the system flexibilities and renewable energy deliveries to the end users without the reinforcement of transmission and distribution system and any constraint from a highly penetrated power system. [ABSTRACT FROM AUTHOR]

Highlights • The dynamic mesh numerical method is validated by the model experiment. • Energy conservation by effective utilization of piston wind is significant. • The energy saving rates are about 13%∼32% in different climatic regions. • The minimum train speed is calculated based on the CO 2 concentration. • From the perspective of thermal environment, the optimal train speed is 30 m/s. Abstract With the flourishing development of the subway construction, it becomes increasingly urgent to improve the subway tunnel environment and reduce the energy consumption of the tunnel ventilation system. The tunnel environment is significantly affected by the piston wind, which is influenced by the train speed. In this paper, a three-dimensional computational model of a subway tunnel is developed and validated through experiments. The model is used to study the carbon dioxide concentration and thermal environment of the subway tunnel. The optimal train speed is proposed with the aim to minimize the volume of mechanical supply air and to optimize the carbon dioxide concentration and thermal environment of the tunnel. In parallel with the considerations of tunnel environment, the subways in 25 cities of China are analyzed to study the energy conservation of the tunnel ventilation system by making full use of piston wind. The results indicate that the optimal train speed is 30 m/s based on the carbon dioxide concentration and thermal environment. The effective utilization of the piston wind can reduce 13%∼32% of the energy consumption for tunnel ventilation. The calculation method of the optimal train speed developed in this paper is also applicable to ordinary railway tunnels and high-speed railway tunnels. [ABSTRACT FROM AUTHOR]

Coal is the dominant fuel for electricity generation around the world. This type of electricity generation uses large amounts of water, increasing pressure on water resources. This calls for an in-depth investigation in the water-energy nexus of coal-fired electricity generation. In China, coal-fired power plants play an important role in the energy supply. Here we assessed water consumption of coal-fired power plants (CPPs) in China using four cooling technologies: closed-cycle cooling, once-through cooling, air cooling, and seawater cooling. The results show that water consumption of CPPs was 3.5 km 3 , accounting for 11% of total industrial water consumption in China. Eighty-four percent of this water consumption was from plants with closed-cycle cooling. China’s average water intensity of CPPs was 1.15 l/kWh, while the intensity for closed-cycle cooling was 3–10 times higher than that for other cooling technologies. About 75% of water consumption of CPPs was from regions with absolute or chronic water scarcity. The results imply that the development of CPPs needs to explicitly consider their impacts on regional water resources. [ABSTRACT FROM AUTHOR]

The mobilized thermal energy storage (M-TES) system is a promising alternative to conventional heating systems to meet the heat demand for distributed users. This paper provided a techno-economic assessment of the M-TES system based on a case study in China. According to the analysis of the design specifications of the heating system, the suitability of matching the M-TES with existing heating systems was analyzed. The results show that the M-TES is appropriate for use with heating systems with a fan-coil unit and under-floor pipe. Containers and operating strategies for the M-TES with different transportation schemes were also designed. The maximum allowed load of the M-TES container is 39 t according to the discussion of transportation regulations on the road. The cost and income of the M-TES in the study case were estimated, and the net present value (NPV) and payback period (PBP) were also calculated. The best operating strategy is the use of 2 containers and 4 cycles of container transportation per day, with a PBP of approximately 10 years. The M-TES is applicable for middle and small-scale heat users in China. [ABSTRACT FROM AUTHOR]

Solar energy for building applications may significantly reduce the conventional energy consumption and the related carbon dioxide emissions. The comprehensive utilization of integrated solar thermal and photovoltaic systems is undoubtedly a subject of interest. In the present paper, an optimization model was proposed for integrated solar energy systems, aiming to figure out the optimal utilization and economical efficiency of solar energy resources for buildings in cold plateau areas. A case study in Lhasa city was further carried out in order to evaluate the energy and economic performance of the developed model. The results indicated that solar photovoltaic systems are preferred than solar thermal systems for typical office buildings in cold plateau areas with rich solar energy resources. In addition, a sensitivity analysis was performed to investigate the influences of financial subsidies and commercial electricity prices on the system economical performance. Furthermore, life cycle assessment was conducted to compare and analyze the performances of an optimization system and a conventional system. [ABSTRACT FROM AUTHOR]

Expansion by photovoltaic (PV) technologies in the renewable energy market requires exploring added value integrated with business model innovation. In recent years, a pilot trial of PV water pumping (PVWP) technologies for the conservation of grassland and farmland has been conducted in China. In this paper, we studied the added value of the PVWP technologies with an emphasis on the integration of the value proposition with the operation system and customer segmentation. Using the widely used existing PV business models (PV-roof) as a reference, we evaluated discounted cash flow (DCF) and net present value (NPV) under the scenarios of traditional PV roof, PVWP pilot, PVWP scale-up, and PVWP social network, where further added value via social network was included in the business model. The results show that the integrated PVWP system with social network products significantly improves the performance in areas such as the discounted payback period, internal rate of return (IRR), and return on investment (ROI). We conclude that scenario PVWP social network with business model innovation, can result in value add-ins, new sources of revenue, and market incentives. The paper also suggests that current policy incentives for PV industry are not efficient due to a limited source of revenue, and complex procedures of feed-in tariff verification. [ABSTRACT FROM AUTHOR]

[Display omitted] • This paper summaries the present regulations and policies concerning M−TES (Mobilized thermal energy storage) in China. • The policies are analyzed based on the aspects including facility manufacture and operation, road transportation, and financial guidance. • The results can provide references for the government or policy makers to promote the development and safe operation of M−TES in China. Mobilized thermal energy storage (M−TES) is a promising technology to transport heat without the limitation of pipelines, therefore suitable for collecting distributed renewable or recovered resources. In particular, the M−TES can be flexibly used for the emergency heating in the COVID-19 era. Though the M−TES has been commercializing in China, there is not any specific regulation or standard for M−TES systems. Therefore, this paper summarizes and discusses the existing regulations and policies concerning M−TES in the aspects of facility manufacture and operation, road transportation, and financial support and guidance. Furthermore, the suggestions were presented including necessary consensus on the development of M−TES among different departments, consideration of local conditions when drafting or revising regulations and policies, sufficient investment, or subsidy on the R&D of M−TES, and qualification recognition of M−TES companies and staffs. [ABSTRACT FROM AUTHOR]

• A spatiotemporal model to estimate the photovoltaic (PV) potential of highways is developed. • The dynamic shadows of the surrounding terrain on the highway surface are considered. • By 2020, the mileage of Chinese highway was 143,684 km and the area was 3,957 km2. • The installed capacity and power generation of PV highways in China are 700.85 GW and 629.06 TWh, respectively. Installing photovoltaic (PV) modules on highways is considered a promising way to support carbon neutrality in China. However, collecting the area of the highway, and precisely assessing the shadow area of the highway under complex terrain remain challenges. That severely hinders the assessment of highway PV potential. To address these challenges, a spatiotemporal model is developed in this study to estimate the annual solar PV potential on highways over the whole Chinese territory. First, the areas of different highway segments are calculated based on highway network and highway toll stations. Second, hourly shadow area on highways created by nearby terrain is estimated based on a digital elevation model (DEM). When calculating the highway PV potential, the solar irradiation received in these shadow areas is regarded as zero. Finally, the PV potential of all lanes and emergency lanes was estimated at the prefecture-level city scale using surface radiation data and radiation assessment models. Based on the highway data with a total mileage of 143,684 km at the end of 2020, the results show that the annual PV potential is 3,932 TW and that the corresponding installed capacity is 700.85 GW, which can generate clean electricity at a rate of up to 629.06 TWh. The annual PV potential of highways in the southeast is greater than that in the northwest owing to the higher highway density in the southeast. This study provides a reference basis for highway PV construction planning and suitably assessment in each region of China for PV highway development. [ABSTRACT FROM AUTHOR]

• Uncertainty-based multi-objective optimal design method of PVB system was proposed. • Three groups of influencing factors with uncertainty were identified and modeled. • Representative values of technical indicators (SCR and SSR) were defined. • Generic configuration indices of PV and battery capacities were proposed. • The proposed indices can be used directly as guide for PVB system design. In practice, the actual operation conditions are generally different from those assumed in the design stage, which causes uncertainties of actual building load and photovoltaic (PV) power generation. This study conducted an optimization design for PV-battery (PVB) system with consideration of these uncertainties. Three groups of factors with uncertainty, relating to outdoor conditions, building construction and indoor conditions, were discussed. An uncertainty-based multi-objective optimization design method was proposed for the PVB system based on the random simulations and weight sum method. Compared with conventional deterministic optimization method, the uncertainty-based optimization method is more likely to achieve the optimal configuration of PV and batteries in actual conditions. When the weight factors are the same, the impacts of self-consumption rate (SCR) on the PVB system configuration are larger than that of the self-sufficiency rate (SSR). The performance of the PVB system is much more sensitive to PV capacity than to battery capacity. In practice, on the premise of achieving the required SCR , the PV capacity should be maximized while the battery capacity be minimized. Representative values of technical indicators (SCR and SSR), of which a relative deviation of 5% covers more than 84% of all the results, were determined. Based on the representative values, the configuration indices of PV and battery capacities for office buildings in the hot-summer and cold-winter, and the IV solar resource zone of China, were proposed, and summarized in the form of table. The proposed configuration indices can be used directly as guide for PVB system design. [ABSTRACT FROM AUTHOR]

Abstract: Pasture lands in Inner Mongolia of China have been deteriorated severely by overgrazing and climate change in the past 30years. There is a plan to set up a solar irrigation system in Xilamuren area of the region to restore the pastures effectively. In order to design the solar irrigation system based on groundwater, equations for analyzing the optimum irrigation amount were developed in this study, and the main steps to design the system were also given. The coefficients and parameters in the equations are related to meteorological factors, vegetation types and areas, and soil properties. The soil water content is a control variable to decide the water irrigation amount for its effects on maintaining the vegetation growth based on soil water evaporation, plant transpiration and physiological consumption. According to the pasture restoring objectives and water demands during the plants growing periods, proper soil water contents are chosen as evaluation basis for irrigation. The groundwater system should be kept healthy during exploitation; so, the possible supply of local groundwater is a constraint condition in the model. Besides, an optimum irrigation amount process in a whole year is provided for the solar powered system design. [Copyright &y& Elsevier]

• The PV potential of China's 239 civil airports was evaluated. • The airport PV in China is up to 2.5 GW with an annual output of 2.64 TWh. • The power generation potential highly matches the energy demand at airports. • Most airport PV systems can achieve a ROI of over 50% without any subsidy. • The meaning of airport PV is discussed in the context of transport electrification. The airport is one of the most fundamental infrastructures in our society, its terminal buildings and parking lots are ideal locations for photovoltaic (PV) installation. The future trend of the electrification of the aviation and automobile industries will increase the electricity demand at airports calls for the integration of PV systems with airport infrastructure. Understanding the benefits of airport PV systems is crucial for the stakeholders including investors, project developers and policymakers to promote PV sector development. Thus, evaluation of the PV potential and relevant economic performance of airports is essential. Combined with the geographic information system (GIS), the PV potential of the civil airports in China is investigated. The results show that potential PV capacity of China's 239 civil airports reaches up to 2.50 GW. The annual electricity demand of the aviation industry in 8 provinces can be self-satisfied via airport PV generation. Detailed economic analysis shows that all airport PV systems are profitable through appropriate investment and operation strategies. [ABSTRACT FROM AUTHOR]

[Display omitted] • The PV potential of all cooling towers in China is evaluated for the first time. • Total capacity of CT-PV reaches 1.05 GW. • The techno-economic performance of CT-PV in different regions is compared. • 90% of the cities' solar generation electricity prices are below 0.35 CNY/kWh. • CT-PVs located in China's major industrial cities have best overall performance. The deployment of photovoltaic systems based on existing buildings has been the focus of research in recent years. It is necessary to evaluate the techno-economic performance of the new photovoltaic system deployment strategy for its actual implementation. In this paper, we comprehensively evaluated the power generation potential and economic performance of photovoltaics deployed on hyperbolic cooling towers in Mainland China. Based on the local solar radiation situations and electricity prices, we analyzed both the technical and economic performance of cooling towers photovoltaic (CT-PV) located in different cities. The results show that the total capacity of photovoltaic installations on all cooling towers reaches 1.05 GW, with corresponding annual power generation of 1.44 TWh. The total CO 2 emission reduction and total profit by CT-PV cooling towers photovoltaic over a lifetime of 25 years can reach 31 Mts and 8.00 billion CNY, respectively. The return on investment is between 1.1 and 2.49, depending on the location. The payback period for all cities is less than 8 years, and around 90% of the cities' solar generation electricity prices are below 0.35 CNY/kWh, which can compete with the benchmark price of coal-fired electricity. These results reveal that CT-PVs cooling towers photovoltaics have significant potential for PV photovoltaic application with attractive energy and economic benefits. [ABSTRACT FROM AUTHOR]

The industrial process of drinking water treatment requires intensive energy, leading to high enterprise costs and abundant carbon emissions. To ensure cost-effective and low polluting power supply for the above process, this paper proposes to deploy the grid-connected hybrid renewable system. A multi-objective nonlinear dynamic model mixed with integer variables is established for the decision makers, in which both system configurations and operations as well as benefits trade-offs from four dimensions are simultaneously considered. The ε-constraint method and system planner attitude parameters are introduced to transform the proposed model into its equivalent single objective form, which is further been solved by the LINGO software. A case study in China is given to assess the viability of the proposed model, in which optimal system configuration, economically feasible self-sufficiency ratio and optimal energy balance are obtained. Influences of electricity pricing strategies and natural resource changes on the systems are also analyzed and compared. It is found that the deployment of grid-connected hybrid wind/PV/storage system can help power users to cope with the future electricity price variation risks, with the feasible self-sufficiency ratio reaching 95%. • A hybrid renewable system for drinking water treatment plant is proposed. • An optimization model and analysis paradigm are provided for potential appliers. • Real case proved the economically feasible self-sufficiency ratio can reach 95%. • Deployment of above system helps to cope with the electricity price variation risk. [ABSTRACT FROM AUTHOR]

• Evaluated a novel crowdfunding financing mechanism for PVWP with milk production. • Feasibility analyses with DCM on crowdfunding intentions and willingness-to-pay. • Environmental consciousness, child, female are crucial to crowdfunding intentions and WTP. • Online pre-sale purchases trends encourage customers crowdfunding sustainable products. This paper studies the role of potential investors in financing renewable energy systems—specifically, relating to crowdfunding as a financing mechanism, with the enhancement of internet and social-media tools. The research question in this study is whether crowdfunding with a novel socio-technical product reward program attracts potential customers to a more sustainable milk product with a specific integrated photovoltaic water pumping (PVWP) system. The particular case study we empirically investigated is product reward crowdfunding in dairy milk production in China. The milk production chain was supplied by PVWP system integration, which generated solar energy both for feed production for dairy cows and for the operation of dairy farms. 48 semi-structured in-depth interviews were conducted between the research team and customers in order to perform qualitative analyses of the determinants of customers' milk purchase behaviors. In addition, 357 online surveys were collected for quantitative analysis. Binary and ordered probit regressions were employed to use survey date to systematically estimate purchase intention and willingness-to-pay for sustainable milk. Customer behaviors, environmental consciousness, and individual socio-demographic factors were investigated as potential explanatory variables. Over 82% of the survey participants showed intentions to purchase the sustainable milk with the PVWP system. In the survey and interview samples, results showed that milk quality, nutrition improvement, emissions reduction, and environmental benefits attributed to the integrated PVWP system were the major factors considered by interviewees who showed intentions to purchase the crowdfunded dairy milk. Regression model results suggested that potential customers with higher income levels, and those of parenting age, and those with young children or planning to have children, had a higher willingness-to-pay than other customers for the crowdfunded sustainable dairy milk. The familiarity with and popularity of online shopping and pre-sale purchases in China made customers more open to and proactive towards pre-pay and crowdfunding mechanisms. This article evaluated key factors which may influence potential customers for crowdfunding, and used a discrete choice model to estimate customers' willingness-to-pay for reward-based projects. These results could help producers of sustainable milk products to identify potential target groups in China and estimate market demand. This exploratory study could provide a framework with both quantitative and qualitative assessment of crowdfunding for renewable energy systems in a national or international context. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents the current status of biofuel development and estimates the potential of un-used land for biofuel development. The potential of crops including cassava, sweet potato, sweet sorghum, sugarcane, sugar beet and Jerusalem artichoke were assessed and discussed for different regions considering the geographical conditions and features of agricultural production. If reserved land resources are explored together with substitute planting implemented and unit area yield improved, potential production of ethanol fuel will be 22millionton in 2020. The study also recommends the use of winter idle lands for rapeseed plantation for biofuel production. The potential for production of biodiesel by rapeseed and cottonseed can reach to 3.59millionton. [Copyright &y& Elsevier]