China, People’s Republic

The UK government plans to phase out pure diesel trains by 2040 and fully decarbonize railways by 2050. Hydrogen fuel cell (HFC) trains electrified trains using pantographs (Electrified Trains) and battery electric multiple unit (BEMU) trains are considered the main solutions for decarbonizing railways. However the range of these decarbonization options’ line upgrade cost advantages is unclear. This paper analyzes the upgrade costs of three types of trains on different lines by constructing a cost model and using particle swarm optimization (PSO) including operating costs and fixed investment costs. For the case of decarbonization of the London St. Pancras to Leicester line the electrified train option is more cost-effective than the other two options under the condition that the service period is 30 years. Then the traffic density range in which three new energy trains have cost advantages on different line lengths is calculated. For route distances under 100 km and with a traffic density of less than 52 trips/day BEMU trains have the lowest average cost while electrified trains are the most costeffective in other ranges. For route distances over 100 km the average cost of HFC trains is lower than that of electrified trains at traffic densities below about 45 trips/day. In addition if hydrogen prices fall by 26 % the cost advantage range of HFC trains will increase to 70 trips per day. For route distances under 100 km BEMU trains still maintain their advantages in terms of lower traffic density.

The International Maritime Organization (IMO)’s annual operational carbon intensity index (CII) rating requires that from 1 January 2023 all applicable ships meet both technical and operational energy efficiency requirements. In this paper we conduct a comparative study of different alternative fuel options based on a CII model from the perspective of shipowners. The advantages and disadvantages of alternative fuel options such as liquefied natural gas (LNG) methanol ammonia and hydrogen are presented. A numerical example using data from three China Ocean Shipping (Group) shipping lines is analyzed. It was found that the overall attained CII of different ship types showed a decreasing trend with the increase of the ship’s deadweight tonnage. A larger ship size choice can obtain better carbon emission reduction for the carbon emission reduction investment program using alternative fuels. The recommended options of using LNG fuel and zero-carbon fuel (ammonia and hydrogen) on Route 1 and Route 3 during the study period were analyzed for the shipowners. Carbon reduction scenarios using low-carbon fuels (LNG and methanol) and zero-carbon fuels (ammonia and hydrogen) on Route 2 are in line with IMO requirements for CII.

The affordability and availability of water and energy have a huge impact on food production. Research has shown that there exists a direct and indirect link between power production and clean water generation. Hence the inclusion/importance given to the energy-water-food (EWF) nexus in the United Nations’ sustainable development goals. Acknowledging the importance of decarbonization to the global future there exists a gap in literature on the development of models that can enhance the EWF nexus reduce energy poverty and achieve 100% renewable energy in the electricity sector. Therefore the technical and economic prospect of geothermal energy for bridging the aforementioned gaps in existing works of literature is presented in this study. The energy poverty/wealthy status of a country has been confirmed to have a significant impact on economic development as economic development is largely reflected in the food-water availability. Ditto this study is focused on the interconnectivity of the EWF nexus while incorporating global decarbonization targets. Geothermal energy is of the utmost significance in East Africa due to its abundant potential and distinctive geological features. Located in the Great Rift Valley the region has an abundance of geothermal reservoirs making it an ideal location for geothermal power generation. This study is novel as a comprehensive assessment framework for energy poverty is developed and innovative models utilizing primarily the geothermal resource in the East African region to mitigate this problem are proposed and analyzed. The role of hydrogen generation from critical excess electricity production is also analyzed. The East Africa region is considered the case study for implementing the models developed. A central renewable energy grid is proposed/modelled to meet the energy demand for seven East African countries namely; Ethiopia Tanzania Uganda Djibouti Comoros Eritrea and Rwanda. This study considers 2030 2040 and 2050 as the timestamp for the implementation of the proposed models. The hybrid mix of the biomass power plant solar photovoltaic (PV) pumped hydro storage system and onshore wind power is considered to furthermore show the potency of renewable energy resources in this region. Results showed that the use of geothermal energy to meet energy demands in the case study will mitigate energy poverty and enhance the region’s EWF.

Hydrogen safety is a critical issue during the construction and development of the hydrogen energy industry. Hydrogen refueling stations play a pivotal role in the hydrogen energy chain. In the event of an accidental hydrogen leak at a hydrogen refueling station the ability to quickly predict the leakage location is crucial for taking immediate and effective measures to prevent disastrous consequences. Therefore the development of precise and efficient technologies to predict leakage locations is vital for the safe and stable operation of hydrogen refueling stations. This paper studied the localization technology of high-risk leakage locations in the fuel cell system of a skid-mounted hydrogen refueling station. The hydrogen leakage and diffusion processes in the fuel cell system were predicted using CFD simulations and the hydrogen concentration data at various monitoring points were obtained. Then a multilayer feedforward neural network was developed to predict leakage locations using simulated concentration data as training samples. After multiple adjustments to the network structure and hyperparameters a final model with two hidden layers was selected. Each hidden layer consisted of 10 neurons. The hyperparameters included a learning rate of 0.0001 a batch size of 32 and 10-fold cross-validation. The Softmax classifier and Adam optimizer were used with a training set for 1500 epochs. The results show that the algorithm can predict leakage locations not included in the training set. The accuracy achieved by the model was 95%. This approach addresses the limitations of sensor detection in accurately locating leaks and mitigates the risks associated with manual inspections. This paper provides a feasible method for locating hydrogen leakage in hydrogen energy application scenarios.

Fuel cell hybrid systems due to their combination of the high energy density of fuel cells and the rapid response capability of power batteries have become an important category of new energy vehicles. This paper discusses energy management strategies in hydrogen fuel cell vehicles. Firstly a detailed comparative analysis of existing PID control strategies and Adaptive Equivalent Consumption Minimization Strategies (A-ECMSs) is conducted. It was found that although A-ECMS can balance the energy utilization of the fuel cell and power battery well the power fluctuations of the fuel cell are significant leading to increased hydrogen consumption. Therefore this paper proposes an improved Adaptive Low-Pass Filter Equivalent Consumption Minimization Strategy (A-LPF-ECMS). By introducing low-pass filtering technology transient changes in fuel cell power are smoothed effectively reducing fuel consumption. Simulation results show that under the 6*FTP75 cycle the energy loss of A-LPF-ECMS is reduced by 10.89% (compared to the PID strategy) and the equivalent hydrogen consumption is reduced by 7.1%; under the 5*WLTC cycle energy loss is reduced by 5.58% and equivalent hydrogen consumption is reduced by 3.18%. The research results indicate that A-LPF-ECMS performs excellently in suppressing fuel cell power fluctuations under idling conditions significantly enhancing the operational efficiency of the fuel cell and showing high application value.

Hydrogen-Integrated energy systems (HIESs) are pivotal in driving the transition to a low-carbon energy structure in China. This paper proposes a low-carbon economic scheduling strategy to improve the operational efficiency and reduce the carbon emissions of HIESs. The approach begins with the implementation of a stepwise carbon trading framework to limit the carbon output of the system. This is followed by the development of a joint operational model that combines hydrogen energy use and carbon capture. To improve the energy supply flexibility of HIESs modifications to the conventional combined heat and power (CHP) unit are made by incorporating a waste heat boiler and an organic Rankine cycle. This results in a flexible CHP response model capable of adjusting both electricity and heat outputs. Furthermore a comprehensive demand response model is designed to optimize the flexible capacities of electric and thermal loads thereby enhancing demand-side responsiveness. The integration of electric vehicles (EVs) into the system is analyzed with respect to their energy consumption patterns and dispatch capabilities which improves their potential for flexible scheduling and enables an optimized synergy between the demand-side flexibility and system operations. Finally a low-carbon economic scheduling model for the HIES is developed with the objective of minimizing system costs. The results show that the proposed scheduling method effectively enhances the economy low-carbon performance and flexibility of HIES operation while promoting clean energy consumption deep decarbonization of the system and the synergistic complementarity of flexible supply–demand resources. In the broader context of expanding clean energy and growing EV adoption this study demonstrates the potential of energy-saving emissionreduction systems and vehicle-to-grid (V2G) strategies to contribute to the sustainable and green development of the energy sector.

Solar energy is the largest energy source on Earth. In contrast to the limited andgreenhouse gases-emitting fossil fuels solar energy is inexhaustible carbonneutral and nonpolluting. The conversion of this most abundant but highlydiffused source into hydrogen is increasingly attractive. In nature photosyntheticmicroorganisms exploit solar energy to produce hydrogen via photosynthesiswhich is also known as photobiological hydrogen production. More recentlyvarious types of artificial materials have been developed to hybrid microorgan-isms for converting solar energy into hydrogen namely semiartificial photo-synthesis hydrogen production. Herein the strategies for converting solar energyinto hydrogen with whole-cell biocatalyst are summarized and their potentials forfuture social sustainable development are discussed.

The dynamic response characteristics between the multiple energy flows of electricity-hydrogen-heat in the renewable energy DC off-grid hydrogen production system are highly coupled and nonlinear which leads to the complexity of its energy conversion and transmission law. This study proposes a model to describe the dynamic nonlinear energy conversion and transmission laws specific to such systems. The model develops a nonlinear admittance framework and a conversion characteristic matrix for multi-heterogeneous energy flow subsystems based on the operational characteristics of each subsystem within the DC off-grid hydrogen production system. Building upon this foundation an energy hub model for the hydrogen production system is established yielding the electrical thermal and hydrogen energy outputs along with their respective conversion efficiencies for each subsystem. By discretizing time the energy flow at each time node within the hydrogen production system is computed revealing the system’s dynamic energy transfer patterns. Experiments were conducted using measured wind speed and irradiance data from a specific location in eastern China. Results from selected typical days were analyzed and discussed revealing that subsystem characteristics exhibit nonlinear variation patterns. This highlights the limitations of traditional models in accurately capturing these dynamics. Finally a simulation platform incorporating practical control methods was constructed to validate the model’s accuracy. Validation results demonstrate that the model possesses high accuracy providing a solid theoretical foundation for further in-depth analysis of DC off-grid hydrogen production systems.

The type IV hydrogen storage tank with a polymer liner is a promising storage solution for fuel cell electric vehicles (FCEVs). The polymer liner reduces the weight and improves the storage density of tanks. However hydrogen commonly permeates through the liner especially at high pressure. If there is rapid decompression damage may occur due to the internal hydrogen concentration as the concentration inside creates the pressure difference. Thus a comprehensive understanding of the decompression damage is significant for the development of a suitable liner material and the commercialization of the type IV hydrogen storage tank. This study discusses the decompression damage mechanism of the polymer liner which includes damage characterizations and evaluations influential factors and damage prediction. Finally some future research directions are proposed to further investigate and optimize tanks.

The iron and steel industry (ISI) plays a significant role in carbon emissions contributing approximately 15% of the nation’s total emissions in China. Transitioning to low-carbon practices is crucial for achieving the country’s carbon neutrality goals. This paper reviews the current state of China’s ISI and assesses the feasibility of various decarbonization technologies including hydrogen utilization biomass substitution zero-carbon electricity Carbon Capture Utilization and Storage (CCUS) as well as their combinations. The blast furnace–basic oxygen furnace (BF-BOF) process currently dominates the industry with an overwhelming share of around 90% presenting significant challenges for decarbonization. In contrast the Direct Reduced Iron–Electric Arc Furnace (DRI-EAF) process is still at the demonstration project stage but it is rapidly growing and shows great potential for achieving net-zero emissions. Electric arc furnaces (EAFs) that use scrap steel account for about 9% of production and have the lowest energy consumption. However their production capacity is limited by the availability of scrap steel. Among numerous options blue hydrogen carbon-neutral biomass and CCUS technologies have relatively low costs and high technological maturity. Nevertheless no single technology can currently achieve deep decarbonization while significantly reducing costs. The nation needs to select the most suitable decarbonization strategies based on geographical location infrastructure and economic conditions. The government should enact corresponding policies provide economic incentives and ensure mitigation of the environmental and social impacts during the decarbonization transition.