Search

The freight transport sector is a critical sector for achieving carbon peak and carbon neutrality targets. However, there are many uncertainties regarding the e-commerce development, promotion speed of low-carbon measures, and freight transport technologies. Existing research lacks considering the multiple uncertainties on the low-carbon technological pathway for freight transport. Consequently, a bottom-up National Energy Technology-Transport (NET-Transport) model is developed based on the principle of cost minimization for optimizing the low-carbon transition pathway of the freight transport. The study comprehensively evaluates the sustainable technological pathway, energy saving and carbon emission reduction of various measures, including shifting to low-carbon transport modes, improving transport energy efficiency and promoting clean energy. Results show that the freight transport demand will reach 24.1–60.5 trillion ton-kilometers by 2060. CO 2 emission would peak at 0.8–1.0 billion tons in 2030–2041 if the breakthrough technologies are not developed on a large scale. Carbon neutrality in the freight sector is difficult to achieve by relying on the low-carbon transition of the energy system alone, with 57–555 million tons of remaining CO 2 emissions in 2060. The advanced technologies have significant effects on energy saving and emission reduction. The research, development, and application of hydrogen-fueled heavy trucks should be accelerated. • A National Energy Technology model is established for China's freight transport. • The freight demand under the influence of e-commerce development is forecasted. • The uncertain impacts of various low-carbon measures are investigated. • China's freight transport is difficult to achieve carbon neutrality in 2060. • A low-carbon development pathway is proposed for China's freight transport. [ABSTRACT FROM AUTHOR]

Concerns over supply risks of critical metals used in electric vehicle (EV) batteries are frequently underscored as impediments to the widespread development of EVs. With the progress to achieve carbon neutrality by 2060 for China, projecting the critical metals demand for EV batteries and formulating strategies, especially circular economy strategies, to mitigate the risks of demand-supply imbalance in response to potential obstacles are necessary. However, the development scale of EVs in the transport sector to achieve China's carbon neutrality is unclear, and it remains uncertain to what extent circular economy strategies might contribute to the reduction of primary raw materials extraction. Consequently, we explore the future quantity of EVs in China required to achieve carbon neutrality and quantify the primary supply security levels of critical metals with the effort of battery cascade utilization, technology substitutions, recycling efficiency improvement, and novel business models, by integrating dynamic material flow analysis and national energy technology model. This study reveals that although 18%–30% of lithium and 20%–41% of cobalt, nickel, and manganese can be supplied to EVs through the reuse and recycling of end-of-life batteries, sustainable circular economy strategies alone are insufficient to obviate critical metals shortages for China's EV development. However, the supplementary capacity offered by second-life EV batteries, which refers to the use of batteries after they have reached the end of their first intended life, may prove adequate for China's prospective novel energy storage applications. The cumulative primary demand for lithium, cobalt, and nickel from 2021 to 2060 would reach 5–7 times, 23–114 times, and 4–19 times the corresponding mineral reserves in China. Substantial reduction of metals supply risks apart from lithium can be achieved by the cobalt-free battery technology developments combined with efficient recycling systems, where secondary supply can satisfy the demand as early as 2054. [Display omitted] • Circular economy strategies alone are insufficient to obviate metals shortages. • China's electric vehicle development might face shortage risks of Li, Co, and Ni. • 1/5–2/5 of critical metals can be supplied through reuse and recycling. • Cobalt-free battery technology should be combined with efficient recycling systems. [ABSTRACT FROM AUTHOR]

China has proposed the Renewable Portfolio Standard (RPS) policy to advance the stable development of renewable energy. The RPS requires each province to achieve a stated minimum share of renewable energy power in the total provincial power generation. However, there is an obvious mismatch between the actual capability of generating renewable power and the assigned responsibility for the share of renewable energy power based on the RPS in some provinces. Therefore, this study aims to optimize the renewable power dispatching strategy across provinces for satisfying the RPS requirements in China and to assess the corresponding pressure for each province. A renewable energy power dispatching model is developed, and an economically feasible strategy for dispatching renewable energy power in Chinese provinces in 2020–2022 was obtained. The results indicate that it is necessary to dispatch 395.2 and 140.4 TWh of hydropower and non-hydropower nationwide, respectively, in 2022 to fulfill the RPS target when the COVID-19 is effectively controlled worldwide. If COVID-19 cannot be effectively controlled, 376.6 and 127.8 TWh of hydropower and non-hydropower must be dispatched nationwide to fill the gap. Beijing, Tianjin, Shanghai, and Zhejiang are faced with a relatively high pressure under the RPS target. Finally, a path for each province to achieve its RPS target is proposed. [ABSTRACT FROM AUTHOR]

• Develop a cost-optimal model towards carbon neutrality in the iron and steel industry. • Explore the cost-effective carbon neutral pathway in the iron and steel industry. • Promoting energy-saving technologies is the most effective strategy to reduce CO 2. • Stable scrap supply would assist carbon neutrality in the iron and steel industry. The iron and steel industry is a critical sector for achieving China's carbon neutrality goal. However, existing studies lack considering the multiple constraints including limited resources, technology diffusion and carbon emissions reduction on design of carbon neutral pathway for iron and steel industry. A broader analysis that can integrate resources-technologies-emissions in to a united framework is necessary. To further explore the feasible paths and challenges faced by the iron and steel industry, this study developed the C3IAM/NET-IS (China's Climate Change Integrated Assessment Model/National Energy Technology-Iron and Steel) model to select the optimal technology portfolios. By incorporating 11 measures such as technological innovation, structure adjustment of raw material, clean energy, etc., the integrated impact on CO 2 emissions, energy consumption, raw materials, and costs is analyzed, while the carbon neutral pathway for the iron and steel industry is further investigated. The results show that CO 2 emissions of China's iron and steel industry would peak at about 1514.14–1530.86 million tonnes before 2023. And there would be more than 72.78 million tonnes of CO 2 in 2060, requiring carbon sinks to absorb to achieve carbon neutrality. During 2020–2060, the most effective measure would be the promotion of energy-saving technologies, which would contribute about 22.07% of CO 2 emission reduction. Compared to the EAF (Electric Arc Furnace) with 50% scrap, promoting EAF with 100% scrap would result in cumulative total costs savings of about 4361.04 billion CNY while consuming 15.14 billion tonnes of scrap. To coordinate the goals of carbon neutrality and raw material security, it is necessary to support domestic iron ore enterprises through tax relief and to accelerate the large-scale construction of the scrap recycling industry. [ABSTRACT FROM AUTHOR]

Smart home, is expected to bring great changes to people's lifestyles. By shifting the timing of residents' electricity consumption, smart home can improve the flexibility of the power load, and provide significant potential for power demand responses. These responses can substantially mitigate peak-to-valley power demand gaps and household electricity costs. However, the extent of the likely impacts from smart home participating in power demand response remains unknown, and very limited research has been conducted thereon. Therefore, this study attempts to explore the potential changes in peak-to-valley electricity consumption and electricity costs owing to smart home, by developing a multi-objective smart home integrated management model with the consideration of appliances and household electricity consumption behavioral heterogeneity. The survey data collected in China was employed in the empirical analysis. Results show that smart home participating in power demand response can reduce peak load by 29.3%–49.3%, which is up to 149 GW, and the peak-to-valley difference could be decreased by 37.5%–78.2%. However, significant variance exists for the smart home impacts among households with different structures and individual occupations. Teachers, freelancers, and homeworkers contribute more to this reduction. In addition, the peak-to-valley difference after introducing smart home would shrink from -80.7%–-68.5% to -29.2%–-23.9% for areas with the time-of-use price policy, which performs better than the areas without time-of-use price policy. Regarding the economic benefits, smart home participating the demand response could reduce the investments in the power supply and power grid by 1.13–1.19 trillion RMB in China. • The impacts of smart home participating in power demand response is evaluated. • A smart home integrated management model is established for power demand response. • The heterogeneous characteristics of different in-home devices and behaviors are considered. • Smart home optimization can reduce peak load by 29.3%–49.3%. • Smart home optimization can reduce investment by up to 1.2 trillion RMB. [ABSTRACT FROM AUTHOR]

The Paris Agreement calls for countries to pursue efforts to limit global-mean temperature rise to 2 °C compared to the pre-industrial level. To achieve this, it is essential to accelerate the low-carbon transition of energy system. China is the largest carbon emitter and plays a decisive role in mitigating global climate change. The transition pathways for China to contribute to meeting the global 2 °C target, however, have not been extensively explored. Here we develop a bottom-up national energy technology model (C3IAM/NET), a linear optimization model, to reveal the energy consumption, carbon emissions and technology pathway at the national and sectoral levels in line with the 2 °C climate target. Results show that China's carbon emissions need to peak at the year 2023 and reduce to 3.56 GtCO 2 by mid-century. During the 2020–2050 planning horizon, the remaining carbon budget is estimated to be controlled within 234 GtCO 2 , with a cumulative emission reduction of 165.3 GtCO 2 , of which the power sector bearing the largest share of responsibility, followed by the industry, transportation and building sectors. We project that China's primary energy consumption needs to peak before 2040 and the proportion of non-fossil energy in energy structure needs to reach 76% by 2050, and about 88.4% of electricity production comes from renewables and nuclear energy. [Display omitted] • The economically low-carbon transition pathway of China's energy system is discovered. • The optimal carbon emissions pathway at national and industrial levels is analyzed. • China's CO 2 emissions need to peak at the year 2023 to achieve 2 °C target. • The power sector bearing the largest share of CO 2 emission reduction responsibility. • The proportion of non-fossil energy in total energy needs to reach 76% by 2050. [ABSTRACT FROM AUTHOR]

Blood pressure variability (BPV) is significantly associated with cardiovascular diseases (CVD) and mortality in hemodialysis patients. However, the relationship between blood pressure and CVD in hemodialysis patients is complex and affected by many factors. The present study aimed to assess the association of long‐term predialysis BPV with all‐cause mortality and major adverse cardiovascular events (MACE). One thousand seven hundred twenty‐seven patients receiving maintenance hemodialysis were recruited in nine hemodialysis centers. Predialysis BPV was assessed over 1‐year intervals. Outcomes included all‐cause mortality and MACE during follow‐up periods. The mean age of the final cohort was 59 years, of which 57% were males. Greater predialysis systolic BPV was associated with an increased risk of all‐cause mortality (adjusted hazard ratio, 1.101; 95% confidence intervals 1.064–1.140) and MACE (adjusted hazard ratio, 1.091; 95% confidence intervals 1.059–1.125). Results were similar when systolic BPV was stratified by baseline systolic blood pressure. In conclusion, greater predialysis BPV among hemodialysis patients was associated with all‐cause mortality and MACE. Strategies to reduce blood pressure variability might be beneficial for hemodialysis patients. [ABSTRACT FROM AUTHOR]

• Develop an hourly-resolution, multi-region model with total system cost optimized. • Energy storage technology can meet 85.8%-by-2050 renewable energy penetration. • UHVDC transmission technology is the most economical way for RES integration. • Optimal combination of UHVDC grid and ES can achieve 74.2% renewables penetration. • The cost-optimal operation strategy varies among six regions in planning period. High renewable energy penetration is an effective way to decarbonize the power system. However, many studies focus on the economics of integrating renewables at the generation-side rather than system-wide. This paper aims to explore the cost-optimal operation strategies of a renewable-dominant power system. Considering both cost reduction potential of energy storage technology and regional investment cost variance of ultra-high voltage direct current grids, an hourly-resolution, multi-region model with total system costs minimized is proposed. Moreover, energy storage-based, ultra-high voltage direct current-based, and mixed scenarios are taken into consideration to investigate the economics of high renewables penetration. The results show that energy storage technology can achieve maximum penetration of renewable energy at 85.8% while the total system cost is 11.8% higher than that of ultra-high voltage direct current transmission technology. Although ultra-high voltage direct current grid is the most economical option to integrate renewables, the penetration is 13 percentage points lower than that of energy storage technology. The combination of energy storage technology and ultra-high voltage direct current grid can achieve 74.2% renewable energy penetration, saving 9.4% of total system costs compared to that of energy storage technology only. The cost-optimal option for East and South China is to promote both energy storage and ultra-high voltage direct current technologies. Energy storage technology is preferred among North, Northwest and Northeast China, while ultra-high voltage direct current grid is the optimal option for Center China. [ABSTRACT FROM AUTHOR]

The large-scale application of hydrogen steelmaking technology is expected to substantially accelerate the decarbonization process of the iron and steel industry. However, hydrogen steelmaking projects are still in the experimental or demonstration stage, and scientific investment decision-making methods are urgently needed to support the large-scale development of the technology. When assessing the investment value, existing studies usually only consider the intrinsic project value under a specific pathway, while ignoring the option value under realistic multiple uncertainties in terms of technology, market, and policy, leading to an underestimation of the investment value. To address this issue, this study constructs a real options model to explore the optimal investment timing and revenue of the hydrogen steelmaking project, by taking into account multi-dimensional uncertainties stemming from price fluctuations in the steel market, the development of the carbon market, and technological advances. Additionally, the impacts of various subsidy policies on the investment strategy are also investigated. Least Squares Monte Carlo method is applied to overcome computational challenges posed by dynamic programming under multi-dimensional uncertainties. The results show that: (i) Investment is not recommended based on current crude steel price and hydrogen price. (ii) When the annual reduction rate of hydrogen price reaches 5%, the optimal investment timing would advance to 2036. (iii) On this basis, with the introduction of a 20% green hydrogen subsidy policy, the optimal investment timing would be further brought forward to 2033. The implementation of tax incentives would significantly increase the investment value. The investment value would surge from 170 million CNY to 262 million CNY as the tax rate decreases from 20% to zero. The findings could provide reasonable suggestions for investment decisions under realistic volatile environments, as well as scientific references for policy design, thus facilitating the large-scale and high-level development of hydrogen-based steelmaking technology. • Considering multiple uncertainties in hydrogen steelmaking project decision making. • Building Real Option Model for investment strategy of hydrogen steelmaking project. • Best time to invest is 2036 at 5% decline rate of H 2 price and current steel price. • Analyzing incentive effects of one-time subsidy, H 2 incentives and tax incentives. • Subsidy for H 2 is the most effective incentive to advance the investment timing. [ABSTRACT FROM AUTHOR]

• The share of ground source heat pump needs to be raised 3% annually for 1.5 ℃ goal. • Demands for geothermal and solar need to increase by 138% and 72% in 2 ℃ scenario. • The cost reduction of key technologies can reduce total investment costs by 37%. • Achieving 1.5 ℃ target can obtain 137 trillion CNY net incomes until 2050. To achieve the long-term climate targets of limiting global warming to well below 2 ℃ and 1.5 ℃ relative to pre-industry levels, China's building sector must be deeply decarbonized considering its potential of substantial emissions increase. However, how to deploy the energy technologies and how much we need to pay for China's building sector for achieving the global warming targets remain unknown. Here, we develop a bottom-up national energy technology model for building sector (NET-Building) to explore the optimal energy technology pathways, energy demands as well as costs and benefits for decarbonizing China's building sector under 2 ℃ and 1.5 ℃ targets. The results show that to meet the 2 ℃ target, most of fossil fuel-fired end-use devices and all traditional biomass-fired end-use devices need to be significantly reduced for the whole building sector. To pursue a more aggressive 1.5 ℃ climate goal, both proportions of the ground source heat pump and solar thermal water heater need to be drastically boosted and reach 100% in commercial sector by 2050. The decarbonization of China's building sector under 2 ℃ and 1.5 ℃ targets can obtain 44 and 137 trillion CNY net incomes until 2050, respectively. [ABSTRACT FROM AUTHOR]

Currently, more than 70% of the heated floor area in northern China is heated by coal, which severely burdens energy consumption and the environment. Hence, heating in this area is in urgent need of a shift to cleaner approaches. However, current progress is mainly attributed to the generous and unsustainable subsidies of the government, which have become a considerable financial burden. This paper develops a linear recursive dynamic model to identify economical, clean heating pathways in northern China. Different heating demands and clean technology promoting advances are considered. The results show that rapid promotion of clean heating technologies would save 1161–3026 Mtce (million tons of standard coal equivalent) of energy and avoid 7692–8843 Mt CO 2 , 12–13 Mt CH 4 , 8–9 Mt SO 2 and 7–8 Mt BC emissions cumulatively from 2020 to 2050. For rural residential buildings, biomass pellet furnaces, air source heat pumps and air conditioning should each contribute to about 30% of the heating demands in 2050 to achieve clean heating. However, coal-fired cogeneration should be the major method of coal heating, and mainly serve urban residential buildings and commercial buildings. The consequent energy cost savings of a faster clean heating transition would exceed the increase in investment costs and operational costs. Therefore, promoting clean heating as early as possible is the economical and environmentally friendly choice for northern China in the long run. [ABSTRACT FROM AUTHOR]