Modeling China's interprovincial electricity transmission under low carbon transition
APPLIED ENERGY
Authors: Zhang, Qiang; Chen, Wenying
Abstract
Interprovincial electricity transmission is expected to play an important role towards low carbon transition to facilitate new and renewable energy development in West China to meet the increasing electricity demand in East China. To analyze changes in interprovincial electricity transmission and transmission infrastructure construction under China's Nationally Determined Contributions and the 2-degree target, this study develops an interprovincial electricity transmission model with multi-voltage levels and integrates it with an improved 30province energy system model to simulate reference scenario (REF) and three low carbon scenarios from a whole energy system perspective, CP30 (emissions peak in 2030), CPE (emissions peak in advance) and C2D (2-degree target). In 2050, electricity transmission is expected to increase to 2526.5 TWh, 3299.3 TWh, 3714.2 TWh and 4002.0 TWh under the REF, CP30, CPE and C2D scenarios, respectively, and the ultrahigh-voltage transmission demand is expected to reach 595.5 GW, 843.3 GW 917.0 GW and 1198.0 GW respectively. The overall pattern of electricity transmission will become increasingly complex as long-distance and large-capacity transmission becomes more prominent. Inner Mongolia, Northwest China and Southwest China will be the major sources of electricity transmissions, and the Beijing-Tianjin-Hebei region, Guangdong, Central China and East China will be the major importers. Ultrahigh-voltage lines will form large-capacity and long-distance electricity transmission paths connecting the power generation bases and load centers. These findings suggest that there will be a significant increase in the demand for electricity transmission and infrastructure construction in the future and that the policies promoting ultrahigh-voltage lines development should be enhanced.
H2SO4-doped polybenzimidazole membranes for hydrogen production with acid-alkaline amphoteric water electrolysis
JOURNAL OF MEMBRANE SCIENCE
Authors: Wan, Lei; Xu, Ziang; Wang, Peican; Lin, Yuqun; Wang, Baoguo
Abstract
Acid-alkaline amphoteric water electrolysis is considered as a potential approach for efficient hydrogen production at industrial scale; however, to date synthesized or post-functionized polymer for constructing membranes can hardly meet the requirement of either electrolysis performance or durability aspects. Herein, we synthesize a series of H2SO4-doped PBI-based membranes, including poly (2,2 '-(m-phenylene)-5,5 '-bibenzimidazole) (m-PBI) and poly (4,4 '-diphenylether-5,5 '-bibenzimidazole) (OPBI), for application in acid-alkaline amphoteric water electrolysis system. The H2SO4 doping content, water uptake, swelling ratio, chemical durability and proton conductivity of m-PBI and OPBI membranes are characterized and compared with the perfluorinated sulfonated membrane (Nafion 115). Specifically, the m-PBI membrane doped in 3.0 M H2SO4 attains a current density of 800 mA cm(-2) at cell voltage of 2.0 V at 60 degrees C when applied in an amphoteric water electrolysis, which is superior to the performance of commercial units. Moreover, such system reveals a long-term stability when operating at the current density of 100 mA cm(-2) for 40 h, with an energy consumption of 3.35 kWh m(-3) H-2, offering a possibility for low-energy consumption and scaled hydrogen production technology.