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2024, Volume 11, Issue 2
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2024,
11(2):
1-16.
doi: 10.16516/j.ceec.2024.2.01
Abstract:
Introduction Under the background of "carbon peak and neutrality" target and "ocean power" strategy, the integration of ocean renewable energy represented by offshore wind power and ocean resources represented by marine ranch is the new direction, new situation and new opportunity for the future development and utilization of ocean resources. The article reviews and analyzes the integrated development mode and key technical problems of offshore wind power and marine pasture, in order to provide technical references to the relevant research and engineering projects in China. Method Taking the integration of China's marine resources development needs as the guide, the global development trend of offshore wind power and marine ranch integration was analyzed, and the current situation and shortcomings of China's wind-fishery integration development were clarified. On this basis, the integration mode, equipment design, engineering cases and key technical problems of the integration development of offshore wind power and ocean ranch were analyzed in detail. Finally, a future outlook on the integration development of offshore wind power and ocean ranch in China was discussed. Result Through the analysis of the integrated development mode and key technical problems of the integration of offshore wind power and marine ranch development, the bottlenecks and technical challenges are clarified, and the key breakthrough directions are pointed out, providing scientific guidance and reference basis for the comprehensive development and utilization of offshore resources in China. Conclusion The article illustrates the necessity and feasibility of integrating the development of offshore wind power and marine ranch, and proposes a feasible way to integrate offshore wind power and marine ranch in China.
2024,
11(2):
17-30.
doi: 10.16516/j.ceec.2024.2.02
Abstract:
Introduction A comparative research was conducted to investigate the variation rules of motion responses in various degrees of freedom (DOF) and towline forces in the towing process of three-column submerged floating offshore wind turbines (TC-SFOWT) and four-column submerged floating offshore wind turbines (FC-SFOWT) under different working conditions, through a physical model test using a DTU 10 MW wind turbine. Method Firstly, a free attenuation test was carried out in still water. Then towing process tests were carried out in regular wave and irregular wave environments. The research focuses on the effects of different towline point heights, wave heights, and wave periods on the towing process of SFOWTs. Result These tests yielded the following findings. (1) The analysis related to heave, roll, and pitch natural vibration periods of SFOWTs reveals that the difference in natural vibration periods between the two SFOWT structures in the same DOF is within 5 seconds, the TC-SFOWT exhibits a smaller heave acceleration and longer natural periods of pitch and roll; (2) As wave height increases, the response of SFOWTs in each DOF and the towline force also increase, and the increase in wave height has a greater influence on the heave acceleration and roll angle of the TC-SFOWT under both regular wave and irregular wave conditions, while it has a smaller impact on the pitch angle and towline force; (3) When the wave period differs greatly from the natural period of SFOWTs, an increase in wave period results in a decreasing trend in the SFOWTs' responses across various DOFs, except for heave acceleration; (4) When the towline point is flush with the water level, the towline force amplitudes of the TC-SFOWT and FC-SFOWT are respectively 11.1% and 14.7% lower than those of the other two working conditions. Conclusion In conclusion, the towing motion performance of the FC-SFOWT is better. In actual engineering practices, the towline point height when the structure is self-floating should be arranged at the water surface line, so as to reduce motion response during the towing process.
2024,
11(2):
31-41.
doi: 10.16516/j.ceec.2024.2.03
Abstract:
Introduction The research aims to explore the integrated calculation method of a 10 MW semi-submersible floating wind turbine, and analyze its coupled dynamic response characteristics in 40～50 m offshore deep water areas. Method A 10 MW concrete semi-submersible floating wind turbine was taken as an example, and then numerical calculation was carried out by the integrated calculation method, and its coupled dynamic response under rated and survival conditions was statistically analyzed. Result The horizontal motion of the platform is mainly affected by the wave force, wind loading and mooring stiffness. The maximum value of motion and mooring tension occur in the survival condition, and the heave motion is mainly affected by the wave, but the mean value of the pitch/roll motion is mainly affected by the wind loading, all of which meet the design specification. Conclusion The integrated calculation method better considers the coupled dynamic behavior of floating wind turbines. Due to the limitation of water depth, the optimization of horizontal motion and mooring nonlinearity of offshore floating wind turbines is more important in offshore deep water areas, and the extreme response mainly occurs in survival conditions. The above conclusions provide an important reference for the research and design of the floating offshore wind turbines in offshore deep water area.
2024,
11(2):
42-50.
doi: 10.16516/j.ceec.2024.2.04
Abstract:
Introduction Under the backdrop of "carbon peak and neutrality", coastal provinces and cities in China are gradually developing clean energy towards the ocean. The development of offshore wind farm has begun to take shape and achieved equal price of connection to power grid, and pilot projects for offshore floating photovoltaic (FPV) systems are emerging. The comprehensive development of a variety of marine resources, the intensive use of sea resources in the energy sector, and the creation of an integrated marine energy system are of great significance for coastal provinces to achieve high-quality carbon neutrality. Method The article summarized the current development and pilot projects of offshore FPV technology both inside and outside of China, analyzed the advantages and challenges of various offshore FPV technologies, predicted the future market size of offshore FPV in China, explored the integration development mode of offshore FPV and other offshore infrastructure, and provided the integration scenarios and economic analysis based on case studies. Result The offshore FPV technology is currently at the pilot stage with broad market in the future. The main technical challenge is the viability of floating structure under harsh marine environmental conditions, and the unit cost of the existing pilot projects is relatively high, however, it has enormous potential of combination with other marine facilities. Conclusion The integration of offshore FPV and other offshore facilities such as offshore wind power can effectively improve the utilization efficiency of energy facilities and reduce the cost of construction and operation. The complementary use of marine scenery also effectively solves the stability and security problems of a single energy supply.
2024,
11(2):
51-58.
doi: 10.16516/j.ceec.2024.2.05
Abstract:
Introduction Numerous equipment of offshore wind power projects is located on the ocean, and the inconvenient transportation makes operation and maintenance difficult. It is extremely important for offshore equipment information to be delivered to land quickly, without delay, and safely. In view of the special needs of the communication system, a communication system scheme for offshore wind farms based on 5G technology is proposed. Method First, a PTN+ integrated small base station with large signal coverage and strong reliability was built, and then the 5G integrated small base station with the PTN gateway were integrated to achieve fast and convenient 5G signal coverage through broadband PTN access. The 5G network with specific bandwidth improved the security of the communication system. Result After the completion of the 5G communication system based on PTN+ integrated small base station, IP transmission based on optical transmission, supporting multiple services and using specific bandwidth can be realized. This system can help plan and sort out the wind turbine subsystems, realize all-round signal coverage inside the wind turbine, and can quickly and safely transmit the operation status and data of wind turbines, offshore booster stations and other equipment to the onshore operation and maintenance center. This system can solve the problem of difficult real-time secure transmission of wind turbine multi-subsystems and multi-services. Conclusion The 5G communication system research improves offshore wind power communication, and uses specific bandwidth and emerging technologies to realize the timeliness and reliability of communication in offshore wind farms and improve the communication efficiency of offshore operation and maintenance personnel in offshore wind farms. It meets the communication requirements of offshore equipment in offshore wind power projects and is expected to be applied in engineering.
2024,
11(2):
59-67.
doi: 10.16516/j.ceec.2024.2.06
Abstract:
Introduction In the backdrop of the increasingly scarce availability of sea-based wind farms in near-sea shallow water areas and the trend towards deeper and wider waters, as well as larger and more concentrated facilities, a discussion is presented on a distributed offshore wind energy system that integrates energy and transportation, in order to avoid the commonly encountered issues of large-scale offshore wind farms in open waters, such as extensive sea-area requirements and impacts on shipping safety. Method Based on the existing or planned offshore wind farms in large ports, the best site was selected based on the built-in breakwaters that accompanied the port. After analyzing the functions and layouts of the port basin and the breakwater, the optimal layout of the offshore wind turbines and seabed cables was achieved through optimization. This could lead to improvements in technology, economics, policy, and environment in various aspects. Result Compared to over a dozen existing offshore wind farms built in open waters in China, the distributed offshore wind farm based on energy and transportation can significantly reduce the scope of operations and the area required for construction the sea-area, also lower the impact on shipping in the surrounding area. Furthermore, it is a relatively safe, economic, and environmentally friendly type of offshore wind farm site. Conclusion Through discussions on the selection and layout of distributed offshore wind farms based on energy and transportation, the advantages of this type of offshore wind farm, such as reducing the required sea area, minimizing marine obstacles, integrating supply and consumption, and reducing construction and operation costs, are described. This type of offshore wind farm can serve as an important supplement to the current single type of offshore wind farm and become a new type of incremental offshore wind farm site resource in the current stage.
2024,
11(2):
68-81.
doi: 10.16516/j.ceec.2024.2.07
Abstract:
Introduction In order to facilitate the design optimisation of foundation for offshore wind turbines, it is necessary to promote application of advanced geotechnical constitutive models that are theoretically sound and capable of modelling realistic soil behaviours in real engineering scenarios. Method Firstly, the theoretical framework of the Unified Hardening model (UH model), an advanced constitutive model, was introduced. Then, further modifications oriented to requirements in real engineering applications were presented. Finally, the modified model was applied to the pile-soil analysis of large-diameter monopoles, and the results were analyzed at the macroscopic and element level to verify its effectiveness and practicability. Result The UH_G0 model obtained through modification and verification is applicable to addressing issues in real engineering practices. The parameter "initial void ratio" in the original UH model is replaced by "overconsolidation ratio". By incorporating the Andersen empirical formula, the shear modulus is decoupled from the constitutive parameter κ, significantly improving the initial shear stiffness of the original UH model, and thus allowing the UH model to be applicable to the deformation (stiffness) sensitive boundary value problems. Conclusion As an advanced constitutive model with a well-defined theoretical framework and physically meaningful parameters, the UH model demonstrates high potential for practical engineering applications. The two modifications tailored to engineering design requirements are necessary, which improve the convenience in application of the UH model to address boundary value problems and the accuracy in calculating initial stiffness, respectively. The modified UH_G0 model is proven to be effective and practical for solving practical engineering problems in the process of finite element simulation.
2024,
11(2):
82-92.
doi: 10.16516/j.ceec.2024.2.08
Abstract:
Introduction The offshore wind power industry is among the most pioneering and strategic emerging sectors in the global development of new energy sources. The research focuses on the inclined helical pile-group foundation, which is currently applied for offshore wind turbines, and systematically studies its load-bearing characteristics. It is of great significance to accurately understand the load-bearing characteristics for the subsequent popularization of this promising new type of foundation and the overall development of the offshore wind power industry. Method The effects of various variables, including pile number, pile spacing and inclination angle, on the bearing characteristics of inclined helical pile groups were systematically studied by finite element software, and the change trends of the pile group effect coefficient and bearing capacity with these factors were obtained under various working conditions. Result The results show an approximately 15% improvement in the load carrying capacity of inclined helical pile groups compared to monopoles. Additionally, the efficiency coefficient of pile groups increases with a larger pile number. The load carrying capacity of pile-group foundations is positively correlated with pile spacing, as smaller pile spacing leads to a more significant superposition of central soil pressure. The variation in ultimate load carrying capacity remains within about 4% across the value range of pile spacing. Larger inclination angles enhance the compressive load carrying capacity of inclined helical pile-group foundations, causing an increase in their compression efficiency coefficient. Compressive bearing is found to be effective at an inclination angle of 8°. When subjected to pulling action, the upper soil of inclined helical pile groups experiences less disturbance, the foundations' behavior is more influenced by the pile spacing, and the extreme depth of vertical displacement of the soil at the center of the pile groups gradually decreases with the increase of pile spacing. Conversely, under compressive action, the inclined helical pile-groups exert an influence on the soil in a larger extent, and the interaction effect among piles becomes more stable, without indicating obvious correlation between the extreme depth of vertical displacement of the soil at the center of the pile groups and the pile spacing and inclination angle. Conclusion The research results serve to provide certain research approaches and means for the construction of offshore wind power helical pile-group foundations in China, and hold certain reference significance for the dimensional design and bearing capacity evaluation of inclined helical pile-group foundations, demonstrating their value in scientific research and engineering applications.
2024,
11(2):
93-101.
doi: 10.16516/j.ceec.2024.2.09
Abstract:
Introduction Global climate change and its negative impacts are serious humanitarian challenges. Accelerating the construction of a new energy system and promoting energy transition to green and low-carbon are the key to addressing the above challenge. Building a new power system is the central link in planning and constructing a new energy system. Method The characteristics and challenges in the six stages of constructing a new power system with new energy source as the main body, and potential roles of energy storage were described and analyzed. The viewpoint that energy storage, especially long-term energy storage, is a key technology for building a new power system was proposed. Result To deal with vague concept, unclear technical system and undefined R&D system for long duration energy storage in China, by analyzing the international use cases, the concept system of long-duration energy storage and its technology system covering four categories (including mechanical energy storage, thermal storage, electrochemical energy storage, and chemical energy storage) are proposed. And the R&D trends in developed countries are shown. Conclusion It is expected that the relevant content can provide reference for the research and application of long duration energy storage in China.
2024,
11(2):
102-111.
doi: 10.16516/j.ceec.2024.2.10
Abstract:
Introduction With the large-scale application of new energy, the challenges faced by the grid connection of new energy power generation are growing, and the importance of energy storage system is increasing. carbon dioxide energy storage (CES) technology is a kind of compressed gas energy storage technology emerging in recent years, with the advantages of high energy storage density, long service life and high design flexibility. For liquid carbon dioxide energy storage (LCES) technology, CO2 is stored as liquid phase in both HP and LP sides of the system, which has high energy storage density and strong operation stability. Method Firstly, the operation principle and key technical indicators of the LCES system was introduced and the importance of carbon dioxide liquefaction and common liquefaction processes were clarified. Then, the research status of CO2 liquefaction on the LP side of the LCES system was introduced, including the use of mixed energy storage working medium, self-condensation, the LNG cold energy, and the regenerator. The characteristics of each method were analyzed in detail. Result The research indicates that the application of regenerator is the most effective method. It is necessary to further analyze the challenges faced by current cold storage liquefaction technology and its development direction. Conclusion The research could provide guidance for the further development of CO2 liquefaction technology for the LCES system.
2024,
11(2):
112-124.
doi: 10.16516/j.ceec.2024.2.11
Abstract:
Introduction Energy storage technology becomes an essential supporting technology to build a new power system with renewable energy as the main power source. Liquid air energy storage (LAES) is one of the emerging large-scale energy storage solutions, which is technically and economically feasible and has a wide range of application prospects. The pilot plant built by Highview Power is the only LAES for which test data have been made public. The paper aims to explore the thermodynamic principle of LAES and seek ways to improve the cycle efficiency of LAES. Method A thermodynamic model was established according to the process flow of Highview Power's pilot plant. The thermodynamic model was verified by the test data of the pilot plant. Exergy analysis was carried out. The influence of key operating parameters on the charging and discharging process was studied by the control variable method. Result The results show that the key equipment limiting the cycle efficiency are recycle compressor and evaporator. Increasing the compression pressure and post-throttling pressure, increasing the mass flow rate and inlet temperature of the cryogenic expander, and recovering the cooling capacity of the regenerator are beneficial to improving the liquefaction rate and reducing the energy consumption of liquefaction. Moreover, increasing the high pressure and the inlet temperature of turbine expansion unit can help to improve the output power and cycle efficiency of LAES. Conclusion Some improvement measures are put forward to improve cycle efficiency, such as recovery of compression heat, improvement of compressor isentropic efficiency and reduction of heat transfer temperature difference of evaporator.
2024,
11(2):
125-138.
doi: 10.16516/j.ceec.2024.2.12
Abstract:
Introduction In order to reduce frequency disturbance caused by photovoltaic (PV) generation to power grid and further improve the frequency modulation effect, an optimization strategy for collaborative frequency modulation of PVs-ESs based on MPC (Model Predictive Control) is proposed. The basic principles, control flow, constraints, target function and weight coefficient of the strategy are analyzed. Method A model of optical-storage network based on MPC was constructed and the nonlinear state space equation was derived. In order to verify the frequency modulation effect of this strategy, four different simulation environments were set up: no energy storage, battery storage, mixed energy storage and the strategy proposed in this paper. Result Simulation results show that compared with other scenarios, the proposed strategy is optimal in terms of frequency modulation and the worst in the absence of energy storage. In addition, the hybrid energy storage method is superior to the battery energy storage method. Conclusion The effectiveness of the proposed strategy is validated on the MATLLAB/Simulink platform. In photovoltaic power generation system, optimal control of energy storage and PV maximum power point tracking can make the grid frequency more stable and improve the stability of the whole system. The results of this study can be used as a reference for PV connection.
2024,
11(2):
139-145.
doi: 10.16516/j.ceec.2024.2.13
Abstract:
Introduction Lithium-ion battery has become the most widely used new energy storage technology. However, it is found that the practical service conditions have great impacts on the actual service behaviors of lithium-ion battery energy storage. This paper aims to study the influence of service conditions on the electrochemical performance of lithium-ion battery, so as to provide references for the construction of future lithium-ion battery energy storage projects. Method The effects of operating charge interval, discharge rate and operating temperature on the actual performance of Li-ion battery were tested and analyzed. Result The working SOC range, charge/discharge rage and operating temperature all have great influence on the actual performance of lithium-ion battery. On the one hand, proper adjustment of charge and discharge range can significantly improve the service life. On the other hand, the current commonly used 2 C configuration mode may significantly reduce the service life, while reducing the rete configuration to 1 C is expected to achieve lower levelized cost of energy although it will increase the initial investment. In addition, temperature control is extremely important to the usage of lithium-ion batteries, even single-digit temperature differences can cause significant battery inconformity over long cycle life. Conclusion Lithium-ion battery energy storage with advantages of fast response speed, high adjustment accuracy and flexible configuration will further play an important role in the work of "carbon peak and neutrality" and the gradual construction of the power market. Paying attention to the influence of practical conditions on the performance of lithium-ion battery will further improve the use efficiency of lithium-ion battery energy storage. In summary, the design of the battery working condition according to the demand of the practical application can provide lithium-ion battery energy storage system more excellent performance, and play an important role to realize the "carbon peak and neutrality" goal of our country.
2024,
11(2):
146-153.
doi: 10.16516/j.ceec.2024.2.14
Abstract:
Introduction Compressed air energy storage (CAES), as a long-term energy storage, has the advantages of large-scale energy storage capacity, higher safety, longer service life, economic and environmental protection, and shorter construction cycle, making it a future energy storage technology comparable to pumped storage and becoming a key direction for future energy storage layout. By summarizing the current status of CAES technology, the working principles, challenges, and solutions of different CAES technologies are analyzed, which is provided for the development of CAES technology through research. Method Firstly, the principle of CAES was introduced, the key equipment, such as compressors, turbo-expanders, and heat exchangers, was analyzed, and the key equipment suitable for the CAES was proposed. Then, the commonly used key technologies, development trends, and engineering cases of large-scale CAES were introduced from the perspective of ground key process technologies and underground gas storage facilities. Finally, the future development trend of CAES technology was analyzed. Result The results show that regenerative CAES is currently the mainstream technology in China, and high-temperature heat storage has become the future development direction of CAES, and is also an important way to improve the efficiency of CAES. At the same time, there is still room for improvement in key equipment and technology optimization, cost reduction, and application scenario development of the system. Conclusions CAES, as a long-term energy storage method, plays an important supporting role in the construction of future new power systems.
2024,
11(2):
154-161.
doi: 10.16516/j.ceec.2024.2.15
Abstract:
Introduction The compressed air energy storage system has a very large air storage volume and high pressure, and usually uses the underground salt cavern as the gas storehouse. Project development is constrained by scarce salt cavern resources. The compressed carbon dioxide energy storage system uses the storage tank with the atmospheric flexible gas film to store carbon dioxide gas. The gas film tank has a huge volume and occupies an excessive area, making it difficult to meet the requirements of construction land indicators of the industrial park. In order to achieve the widespread application of the energy storage with gas compression in industrial parks, an energy storage system with binary cycle gas compression is proposed. Method The system integrated the compressed air energy storage and compressed carbon dioxide energy storage systems, and utilized a shared gas storehouse. The gas storehouse adopted specially designed pressure vessels, which were divided into equal-pressure and scalable air chambers and carbon dioxide chambers using flexible membranes. The system could achieve the storage and release of energies through the collaborative work of compressed air circuits and compressed carbon dioxide circuits, while maintaining a constant-pressure operation in the gas storehouse. In order to evaluate the energy storage performance and energy storage density of the system, a preliminary thermodynamic calculation was conducted on the 100 MW/400 MWh energy storage system of the ground gas storehouse with a storage pressure of 3 MPa, followed by an analysis of the engineering feasibility. Result The results show that the energy storage efficiency of the system is 70.20% and energy density is 3.85 kWh/m3. The system is suitable for supporting energy storage in industrial parks and can provide the multi-generation function of electricity, gas, cooling and heating. Compared to electrochemical energy storage, it has significant commercial competitive advantages. Conclusion For energy storage scenarios in industrial parks, the energy storage with binary cycle gas compression has an important potential commercial value due to its flexible location selection, feasible technology, mature equipment, and controllable cost.
2024,
11(2):
162-171.
doi: 10.16516/j.ceec.2024.2.16
Abstract:
Introduction As one of the main tracks of hydrogen energy development, fuel cell vehicle industry plays a key role in the process of transportation decarbonization. In view of the current policy environment and industrial base, it is necessary to systematically analyze the development trend and challenges of China's fuel cell vehicle market. Method A comprehensive discussion of the fuel cell vehicle market focusing on the market factors such as market size, segmentation direction, equipment and hydrogen source price, etc. was provided in this paper. Result The promotion and application effect of China's fuel cell vehicle market is closely related to the strength of policy support, the clarity of the detailed rules of subsidies and the driving force of local advantageous enterprises. In terms of market distribution, it has shown a certain leader effect according to the comprehensive competitiveness of vehicle and fuel cell enterprises. The price of the vehicle and the fuel cell power system has decreased by 5%~20% compared to 2021, but it still costs a lot in application. Conclusion Although China's fuel cell vehicle marketization is still hampered by the high manufacturing cost and hydrogen price, and the lack of infrastructures, but the fuel cell vehicle industry will show great vitality after further developed in performance verification, infrastructure construction and business structure innovation.
2024,
11(2):
172-178.
doi: 10.16516/j.ceec.2024.2.17
Abstract:
Introduction The purpose of this paper is to research and analyze the influence of water resources on the development of the green hydrogen industry in China, reveal the contradiction between water resources and the development of green hydrogen industry, analyze the future development trend of the green hydrogen industry and to provide useful reference for the development layout of renewable energy hydrogen production projects in China. Method In order to prove that water resources could limit the development of the green hydrogen industry in "Northeast China, North China, Northwest China" and other areas, the analysis and the demonstration were made based on the field investigations and the documentary materials, considering water resources policies, water usage in traditional chemical industries, and hydrogen production technologies. Result The analysis results show that under the restriction of China's water resources-related policies, the layout of green hydrogen industry should consider the constraints of water resources, and the large-scale production of green hydrogen and its substitution for fossil energy hydrogen production cannot effectively save water. Instead, it may lead to an increase in water consumption by the chemical industry. Under the constraint of water resources, the development of China's green hydrogen industry must consider the layout from a holistic perspective, fully integrate the development trend of the existing chemical industry, and consider the abundant resources available such as seawater. Conclusion The development of the green hydrogen industry in China should not ignore the problems of existing policy framework, technology level, industrial layout and characteristics of existing resources. When arranging the layout of the green hydrogen projects, the current situation and future trends should be fully considered, and the problems posed by water resources on the green hydrogen industry should be solved from the perspective of the overall planning, the coordinated industrial development and the effective utilization of resources.
2024,
11(2):
179-188.
doi: 10.16516/j.ceec.2024.2.18
Abstract:
Introduction The "carbon peak and neutrality" strategy has put forward a new path for China's energy development, which restricts the use of traditional fossil energy, and promotes the Chinese government to increase its support for the development of the new energy industry. Photovoltaic, as a new energy which is the most accessible and has the widest coverage, has become the first choice to solve the current energy and environmental problems. However, if we want to increase its market scale and realize the vigorous development of photovoltaic industry, it is necessary to find out and solve the pain points and difficulties of the current stage. Method China's policy on the whole photovoltaic industry chain was combed and analyzed to explore the shortcomings of the photovoltaic industry incentive policy. Based on the data from 33 sample enterprises in the A-share market from 2000 to 2021, the DEA model was built and the integrated innovation benefits and scale benefits of China's PV industry under the guidance of policy were explored. And using the panel regression analysis method, the different impacts of different regional policies on the innovation capacity of the upstream, middle and downstream enterprises of the PV industry. were explored. Result The research shows that the policy subsidies have a more significant impact on the innovation benefits of upstream photovoltaic enterprises, which is positively correlated with the development of enterprises in the eastern region. While in the western region, the opposite is the case, and there are certain regional differences. Conclusion It is necessary to improve the preferential policy strength in the photovoltaic technology innovation level, and carry out a reasonable industry chain planning and layout in combination with the regional advantages.
2024,
11(2):
189-197.
doi: 10.16516/j.ceec.2024.2.19
Abstract:
Introduction Since the initiation of China's "reform and opening up" policy in 1978, Guangdong Province has achieved significant progress in economic growth and energy sector development. The provincial economy has shifted from rapid growth to emphasizing high-quality development. In the face of profound changes unseen in a century around the world and the imminent need to achieve "carbon peak and neutrality" goals, as well as industrial transformation and upgrading, the underlying relationship between energy consumption and economic development has gradually evolved in Guangdong. Therefore, a comprehensive understanding of this new relationship serves as a theoretical grounding for the allotment of resources and utilization of opportunities arising under the "carbon peak and neutrality" goals, which is indispensable to facilitating high-quality and coordinated development in the energy sector and economy development. Method A quantitative analysis of the relationship between energy consumption and economic growth in different development stages of Guangzhou since 1987 was presented, using representative energy and economic indicators and through the Granger causality test. Result The results reveal that the relationship between energy consumption and economic growth in Guangdong is not statistically consistent throughout the entire period from 1987 until now. However, economic development became a significant Granger cause for the surge in energy consumption after Guangdong entered its middle and later stage of industrialization in the mid-90s. Conclusion Guangdong has experienced a changing relationship between energy and economy in its different stages of development since 1987. The rapid growth of the manufacturing sector has stimulated the growth in energy consumption, exhibiting a distinct characteristic of demand-driven growth.
2024,
11(2):
198-207.
doi: 10.16516/j.ceec.2024.2.20
Abstract:
Introduction An environmentally friendly technology that harnesses green renewable solar energy to generate thermal energy for seawater desalination is proposed and the design of a novel fibrous membrane evaporator with full-spectrum absorption capability is introduced, aiming to address global challenges such as environmental pollution and freshwater scarcity. Method The proposed technological process began with the preparation of nano-scale C@TiO2 fibrous membranes using the electrospinning process. These membranes then underwent in-situ carbothermal reduction at 800 ℃ for 2 hours, resulting in the production of carbon-based ceramic C@Ti4O7 photothermal conversion materials with a dark color. Result The results show that the C@Ti4O7 fibrous membrane exhibits a band gap much lower than that of W-TiO2 and excellent solar light absorption capability across a wide range of wavelengths from 200 to 2500 nm, due to the doping of C elements and Ti3+ and the presence of oxygen vacancy defects. Under a light intensity of 1 kW/m2, the surface temperature of the C@Ti4O7 fibrous membrane, floating at the air-seawater interface, can quickly rise to 74.55 °C. Consequently, the evaporation rate of seawater increases to 1.55 kg/(m2·h), resulting in a photothermal conversion efficiency as high as 90.68%. With a light intensity of 5 kW/m2, the evaporator can generate electrical signals of up to 460 mV. In addition, it is proven workable continuously for 30 days in the simulated seawater with NaCl mass fraction of 10%, without salt deposition on the surface. Conclusion Therefore, the adoption of carbon-based ceramic C@Ti4O7 as the photothermal conversion material for the solar-driven interfacial evaporator offers not only high efficiency in photothermal conversion, but also great potential for large-scale applications, demonstrating a broad application prospect in the field of seawater desalination.
