Applications & Pathways

In the field of rail transit the UK Department of Transport stated that it will realize a comprehensive transformation of UK railways by 2050 abandoning traditional diesel trains and upgrading them to new environmentally friendly trains. The current mainstream upgrade methods are electrification and hydrogen fuel cells. Comprehensive upgrades are costly and choosing the optimal upgrade method for trams and mainline railways is critical. Without a sensitivity analysis it is difficult for us to determine the influence relationship between each parameter and cost resulting in a waste of cost when choosing a line reconstruction method. In addition by analyzing the sensitivity of different parameters to the cost the primary optimization direction can be determined to reduce the cost. Global higher-order sensitivity analysis enables quantification of parameter interactions showing non-additive effects between parameters. This paper selects the main parameters that affect the retrofit cost and analyzes the retrofit cost of the two upgrade methods in the case of trams and mainline railways through local and global sensitivity analysis methods. The results of the analysis show that given the current UK rail system it is more economical to choose electric trams and hydrogen mainline trains. For trams the speed at which the train travels has the greatest impact on the final cost. Through the sensitivity analysis this paper provides an effective data reference for the current railway upgrading and reconstruction plan and provides a theoretical basis for the next step of train parameter optimization.

The shift from centralized to distributed generation and the need to address energy shortage and achieve the sustainability goals are among the important factors that drive increasing interests of governments planners and other relevant stakeholders in microgrid systems. Apart from the distributed renewable energy resources fuel cells (FCs) are a clean pollution-free highly efficient flexible and promising energy resource for microgrid applications that need more attention in research and development terms. Furthermore they can offer continuous operation and do not require recharging. This paper examines the exciting potential of FCs and their utilization in microgrid systems. It presents a comprehensive review of FCs with emphasis on the developmental status of the different technologies comparison of operational characteristics and the prevailing techno-economic barriers to their progress and the future outlook. Furthermore particular attention is paid to the applications of the FC technologies in microgrid systems such as grid-integrated grid-parallel stand-alone backup or emergency power and direct current systems including the FC control mechanisms and hybrid designs and the technical challenges faced when employing FCs in microgrids based on recent developments. Microgrids can help to strengthen the existing power grid and are also suitable for mitigating the problem of energy poverty in remote locations. The paper is expected to provide useful insights into advancing research and developments in clean energy generation through microgrid systems based on FCs.

This paper investigates the economic competitiveness of hydrogen-powered trucks. It reviews the growing number of papers that provide an estimate of the total cost of ownership (TCO) of hydrogen-powered trucks relative to their diesel equivalents. It examines the methodology applied the variables considered the data used for estimation and the results obtained. All reviewed studies conclude that hydrogen-powered trucks are not currently cost-competitive while they might become competitive after 2030. The conclusion holds across truck types and sizes hydrogen pathways mission profiles and countries. However we find that there is still a huge area of uncertainty regarding the purchase price of hydrogen-powered trucks and the cost of hydrogen which hampers the reliability of the results obtained. Various areas of methodological improvements are suggested.

The utilisation of hydrogen in ships has important potential in terms of achieving the decarbonisation of waterway transport which produces approximately 3% of the world’s total emissions. However the utilisation of hydrogen drives in maritime and inland shipping is conditioned by the efficient and safe storage of hydrogen as an energy carrier on ship decks. Regardless of the type the constructional design and the purpose of the aforesaid vessels the preferred method for hydrogen storage on ships is currently high-pressure storage with an operating pressure of the fuel storage tanks amounting to tens of MPa. Alternative methods for hydrogen storage include storing the hydrogen in its liquid form or in hydrides as adsorbed hydrogen and reformed fuels. In the present article a method for hydrogen storage in metal hydrides is discussed particularly in a certified low-pressure metal hydride storage tank—the MNTZV-159. The article also analyses the 2D heat conduction in a transversal cross-section of the MNTZV-159 storage tank for the purpose of creating a final design of the shape of a heat exchanger (intensifier) that will help to shorten the total time of hydrogen absorption into the alloy i.e. the filling process. Based on the performed 3D calculations for heat conduction the optimisation and implementation of the intensifier into the internal volume of a metal hydride alloy will increase the performance efficiency of the shell heat exchanger of the MNTZV-159 storage tank. The optimised design increased the cooling power by 46.1% which shortened the refuelling time by 41% to 2351 s. During that time the cooling system which comprised the newly designed internal heat transfer intensifier was capable of eliminating the total heat from the surface of the storage tank thus preventing a pressure increase above the allowable value of 30 bar.

The use of hydrogen in internal combustion engines is a promising solution for the decarbonisation of the transport sector. The current transition scenario is marked by the unavailability and storage challenges of hydrogen. Dual fuel combustion of hydrogen and gasoline in current spark ignition engines is a feasible solution in the short and medium term as it can improve engine efficiency reduce pollutant emissions and contribute significantly in tank to wheel decarbonisation without major engine modification. However new research is needed to understand how the incorporation of hydrogen affects existing engines to effectively implement gasoline-hydrogen dual fuel option. Understanding the impact of hydrogen on the combustion process (e.g. combustion speed) will guide and optimize the operation of engines under dual fuel combustion conditions. In this work a commercial gasoline direct injection engine has been modified to operate with gasolinehydrogen fuels. The experiments have been carried out at various air–fuel ratios ranging from stoichiometric to lean combustion conditions at constant engine speed and torque. At each one of the 14 experimental points 200-cycle in-cylinder pressure traces were recorded and processed with a quasi-dimensional diagnostic model and a combustion speed analysis was then carried out. It has been understood that hydrogen mainly reduces the duration of the first combustion phase. Hydrogen also enables to increase air excess ratios (lean in fuel combustion) without significantly increasing combustion duration. Furthermore a correlation is proposed to predict combustion speed as a function of the fuel and air mixture properties. This correlation can be incorporated to calculate combustion duration in predictive models of engines operating under different fuel mixtures and different geometries of the combustion chamber with pent-roof cylinder head and flat piston head.

This paper investigates the feasibility of hydrogen-powered hybrid electric vehicles as a solution to transportation-related pollution. It focuses on optimizing energy use to improve efficiency and reduce emissions. The study details the creation and real-time performance assessment of a hydrogen hybrid electric vehicle (HHEV)system using an STM32F407VG board. This system includes a fuel cell (FC) as the main energy source a battery (Bat) to provide energy during hydrogen supply disruptions and a supercapacitor (SC) to handle power fluctuations. A multi-agent-based artificial intelligence tool is used to model the system components and an energy management algorithm (EMA) is applied to optimize energy use and support decision-making. Real Global Positioning System (GPS) data are analyzed to estimate energy consumption based on trip and speed parameters. The EMA developed and implemented in real-time using Matlab/Simulink(2016) identifies the most energy-efficient routes. The results show that the proposed vehicle architecture and management strategy effectively select optimal routes with minimal energy use.

Conventional turboshaft engines are high power density movers suffering from low efficiency at part power operation and producing significant emissions. This paper presents a design exploration and feasibility assessment of a hybrid hydrogen-fueled powerplant for Urban Air Mobility (UAM) rotorcraft. A multi-disciplinary approach is devised comprising models for rotorcraft performance tank and subsystems sizing and engine performance. The respective trade-offs between payload-range and mission level performance are quantified for kerosene-fueled and hybrid hydrogen tilt-rotor variants. The effects of gas turbine scaling and fuel cell pressurization are evaluated for different hybridization degrees. Gas turbine scaling with hybridization (towards the fuel cell) results in up to 21% benefit in energy consumption relative to the non-scaled case with the benefits being more pronounced at high hybridization degrees. Pressurizing the fuel cell has shown significant potential as cell efficiency can increase up to 10% when pressurized to 6 bar which translates to a 6% increase in overall efficiency. The results indicate that current fuel cells (1 kW/kg) combined with current hydrogen tank technology severely limit the payload range capability of the tilt-rotor. However for advanced fuel cell technology (2.5 kW/kg) and low ranges hybrid powerplant show the potential to reduce energy consumption and reduce emissions footprint.

Clean energy vehicles (CEVs) e.g. battery electric vehicles (BEVs) and fuel cell electric vehicles (FCEVs) are being adopted gradually to substitute for internal combustion engine vehicles (ICEVs) around the world. The fueling infrastructure is one of the key drivers for the development of the CEV market. When the government develops funding policies to support the fueling infrastructure development for FCEVs and BEVs it has to assess the effectiveness of different policy options and identify the optimal policy combination which is very challenging in transportation research. In this paper we develop a system dynamics model to study the feedback mechanism between the fueling infrastructure funding policies and the medium- to long-term diffusion of FCEVs and BEVs and the competition between FCEVs and BEVs based on relevant policy and market data in Guangzhou China. The results of the modeling analysis are as follows. (1) Funding hydrogen refueling stations and public charging piles has positive implications for achieving the substitution of CEVs for ICEVs. (2) Adjusting the funding ratio of hydrogen refueling stations and public charging piles or increasing the funding budget and extending the funding cycle does not have a significant impact on the overall substitution of CEVs for ICEVs but only impacts the relative competitive advantage between FCEVs and BEVs. (3) An equal share of funding for hydrogen refueling stations and public charging piles would have better strategic value for future net-zero-emissions urban transportation. (4) Making a moderate-level full investment in hydrogen refueling stations coupled with hydrogen refueling subsidies can provide the ideal conditions for FCEV diffusion.

More than 80% of the energy from fossil fuels is utilized in homes and industries. Increased use of fossil fuels not only depletes them but also contributes to global warming. By 2050 the usage of fossil fuels will be approximately lower than 80% than it is today. There is no yearly variation in the amount of CO2 in the atmosphere due to soil and land plants. Therefore an alternative source of energy is required to overcome these problems. Biohydrogen is considered to be a renewable source of energy which is useful for electricity generation rather than relying on harmful fossil fuels. Hydrogen can be produced from a variety of sources and technologies and has numerous applications including electricity generation being a clean energy carrier and as an alternative fuel. In this review a detailed elaboration about different kinds of sources involved in biohydrogen production various biohydrogen production routes and their applications in electricity generation is provided.

The necessity to move to sustainable energy solutions has inspired an investigation of innovative technologies for satisfying educational institutions’ sustainable energy needs. The possibility of a solar-hydrogen storage system and its integration into university energy management is investigated in this article. The study opens by providing context noting the growing relevance of renewable energy in universities as well as the necessity for effective energy storage systems. The goal is to delve into solar-hydrogen technology outlining its components operating mechanism and benefits over typical storage systems. The chapter on Integration Design examines current university energy infrastructure identifies problems and provides ways for integrating solar-hydrogen systems seamlessly. This integration relies heavily on technological and economic considerations such as a cost-benefit analysis and scalability studies. Case studies include real-world examples performance measurements and significant insights learned from successful implementations. The chapter Future Prospects investigates new trends in solar-hydrogen technology as well as the impact of government legislation providing a forward-looking viewpoint for colleges considering adoption. The report concludes with a summary of significant findings emphasizing the benefits of solar-hydrogen integration and making recommendations for future implementations. The limitation of this research is that it only focuses on design and simulation as a phase of preliminary study.