Applications & Pathways

Due to their environmental protection and high power generation efficiency the control technology of hydrogen fuel cells (HFCs) connected to the microgrid has become a research hotspot. However when they encounter peak demand or transient events the lack of power cannot be compensated immediately by HFCs which results in sudden changes of the voltage and frequency. The improved virtual synchronous generator (VSG) control strategy based on HFCs and supercapacitors (SCs) combined power generation system is proposed to overcome this shortcoming in this paper. The small-signal model for designing the combined system parameters is provided which are in accordance with the system loop gain phase angle margin and adjustment time requirements. Besides the voltage and current double closed-loop based on sequence control is introduced in the VSG controller. The second-order generalized integrator (SOGI) is utilized to separate the positive and negative sequence components of the output voltage. At the same time a positive and negative sequence voltage outer loop is designed to suppress the negative sequence voltage under unbalanced conditions thereby reducing the unbalance of the output voltage. Finally simulation results in MATLAB/Simulink environment verify that the proposed method has better dynamic characteristics and higher steady-state accuracy compared with the traditional VSG control

The trend to replace traditional fossil fuel vehicles is becoming increasingly apparent. The replacement concerns the use of pure biofuels or in blends with traditional fuels the use of hydrogen as an alternative fuel and above all the introduction of electric propulsion. The introduction of new types of vehicle propulsion affects the demand for specific fuels the needs for new infrastructure or the nature of the emissions to the environment generated by fuel production and vehicle operation. The article presents a mathematical model using the difference of two logistic functions the first of which describes the development of the production of a specific type of vehicle and the second the withdrawal of this type of vehicle from traffic after its use. The model makes it possible to forecast both the number of vehicles of each generation as a function of time as well as changes in energy demand from various sources and changes in exhaust emissions. The results of the numerical simulation show replacing classic vehicles with alternative vehicles increases the total energy demand if the generation of the next generation occurs earlier than the decay of the previous generation of vehicles and may decrease in the case of overlapping or delays in the creation of new vehicles compared to the course of the decay function of the previous generation. For electric vehicles carbon dioxide emissions are largely dependent on the emissions from electricity generation. The proposed model can be used to forecast technology development variants as well as analyze the current situation based on the approximation of real data from Vehicle Registration Offices.

The hydrogen storage tank is a key parameter of the hydrogen storage system in hydrogen fuel cell vehicles (HFCVs) as its safety determines the commercialization of HFCVs. Compared with other types the type IV hydrogen storage tank which consists of a polymer liner has the advantages of low cost lightweight and low storage energy consumption but meanwhile higher hydrogen permeability. A detailed review of the existing research on hydrogen permeability of the liner material of type IV hydrogen storage tanks can improve the understanding of the hydrogen permeation mechanism and provide references for following-up researchers and research on the safety of HFCVs. The process of hydrogen permeation and test methods are firstly discussed in detail. This paper then analyzes the factors that affect the process of hydrogen permeation and the barrier mechanism of the liner material and summarizes the prediction models of gas permeation. In addition to the above analysis and comments future research on the permeability of the liner material of the type IV hydrogen storage tank is prospected.

Green Print -  Future Heat for Everyone draws together technical consumer and economic considerations to create a pioneering plan to transition 22 million UK homes to low carbon heat by 2050.<br/>Our Green Print underlines the scale of the challenge ahead acknowledging that a mosaic of low carbon heating solutions will be required to meet the needs of individual communities and setting out 12 key steps that can be taken now in order to get us there<br/>The Climate Change Committee (CCC) estimates an investment spend of £250bn to upgrade insulation and heating in homes as well as provide the infrastructure to deliver the energy.<br/>This is a task of unprecedented scale the equivalent of retro-fitting 67000 homes every month from now until 2050. In this Report Cadent takes the industry lead in addressing the challenge.

Mass-produced off-the-shelf automotive air compressors cannot be directly used for boosting a fuel cell vehicle (FCV) application in the same way that they are used in internal combustion engines since the requirements are different. These include a high pressure ratio a low mass flow rate a high efficiency requirement and a compact size. From the established fuel cell types the most promising for application in passenger cars or light commercial vehicle applications is the proton exchange membrane fuel cell (PEMFC) operating at around 80 ◦C. In this case an electric-assisted turbocharger (E-turbocharger) and electric supercharger (single or two-stage) are more suitable than screw and scroll compressors. In order to determine which type of these boosting options is the most suitable for FCV application and assess their individual merits a co-simulation of FCV powertrains between GT-SUITE and MATLAB/SIMULINK is realised to compare vehicle performance on the Worldwide Harmonised Light Vehicle Test Procedure (WLTP) driving cycle. The results showed that the vehicle equipped with an E-turbocharger had higher performance than the vehicle equipped with a two-stage compressor in the aspects of electric system efficiency (+1.6%) and driving range (+3.7%); however for the same maximal output power the vehicle’s stack was 12.5% heavier and larger. Then due to the existence of the turbine the E-turbocharger led to higher performance than the single-stage compressor for the same stack size. The solid oxide fuel cell is also promising for transportation application especially for a use as range extender. The results show that a 24-kWh electric vehicle can increase its driving range by 252% due to a 5 kW solid oxide fuel cell (SOFC) stack and a gas turbine recovery system. The WLTP driving range depends on the charge cycle but with a pure hydrogen tank of 6.2 kg the vehicle can reach more than 600 km.

To solve the challenge of decarbonizing the transport sector a broad variety of alternative fuels based on different concepts including Power-to-Gas and Power-to-Liquid and propulsion systems have been developed. The current research landscape is investigating either a selection of fuel options or a selection of criteria a comprehensive overview is missing so far. This study aims to close this gap by providing a holistic analysis of existing fuel and drivetrain options spanning production to utilization. For this purpose a case study for Germany is performed considering different vehicle classes in road rail inland waterway and air transport. The evaluated criteria on the production side include technical maturity costs as well as environmental impacts whereas on the utilization side possible blending with existing fossil fuels and the satisfaction of the required mission ranges are evaluated. Overall the fuels and propulsion systems Methanol-to-Gasoline Fischer–Tropsch diesel and kerosene hydrogen battery-electric propulsion HVO DME and natural gas are identified as promising future options. All of these promising fuels could reach near-zero greenhouse gas emissions bounded to some mandatory preconditions. However the current research landscape is characterized by high insecurity with regard to fuel costs depending on the predicted range and length of value chains.

The increase in greenhouse gas emissions as well as the risk of fossil fuel depletion has prompted a transition to electric transportation. The European Union aims to substantially reduce pollutant emissions by 2035 through the use of renewable energies. In aviation this transition is particularly challenging mainly due to the weight of onboard equipment. Traditional electric motors with radial magnetic flux have been replaced by axial magnetic flux motors with reduced weight and volume high efficiency power and torque. These motors were initially developed for electric vehicles with in-wheel motors but have been adapted for aviation without modifications. Worldwide there are already companies developing propulsion systems for various aircraft categories using such electric motors. One category of aircraft that could benefit from this electric motor development is traditionally constructed training aircraft with significant remaining flight resource. Electric repowering would allow their continued use for pilot training preparing them for future electrically powered aircraft. This article presents a study on the feasibility of repowering a classic training aircraft with an electric propulsion system. The possibilities of using either a battery or a hybrid source composed of a battery and a fuel cell as an energy source are explored. The goal is to utilize components already in production to eliminate the research phase for specific aircraft components.

The need to reduce CO2 emissions to zero by 2050 has meant an increasing focus on high emitting industrial sectors such as steel. However significant uncertainties remain as to the rate of technology diffusion across steel production pathways in different regions and how this might impact on climate ambition. Informed by empirical analysis of historical transitions this paper presents modelling on the regional deployment of Direction Reduction Iron using hydrogen (DRI-H2). We find that DRI-H2 can play a leading role in the decarbonisation of the sector leading to near-zero emissions by 2070. Regional spillovers from early to late adopting regions can speed up the rate of deployment of DRI-H2 leading to lower cumulative emissions and system costs. Without such effects cumulative emissions are 13% higher than if spillovers are assumed and approximately 15% and 20% higher in China and India respectively. Given the estimates of DRI-H2 cost-effectiveness relative to other primary production technologies we also find that costs increase in the absence of regional spillovers. However other factors can also have impacts on deployment emission reductions and costs including the composition of the early adopter group material efficiency improvements and scrap recycling rates. For the sector to achieve decarbonisation key regions will need to continue to invest in low carbon steel projects recognising their broader global benefit and look to develop and strengthen policy coordination on technologies such as DRI-H2.

Hydrogen fuel cell vehicle (FCV) technology has significant implications on energy security and environmental protection. In the past decade China has made great progress in the hydrogen and FCV industry considering both the government’s policy issuances and enterprises’ production. However there are still some technological and cost challenges obstructing the commercialization of FCVs. Herein the status of China’s hydrogen FCV industry is analyzed comprehensively from three perspectives: policy support market application and technology readiness level. The unique characteristics and key issues in each part of the industry chain are emphasized. Furthermore the energy environmental and economic performances of FCV in the life-cycle perspective are reviewed and summarized based on pre-existing literature and reports. The life-cycle analysis of hydrogen and FCV indicates that the energy and environmental impacts of FCVs are highly related to the sources of hydrogen. With the combination of industry status and technology performances it is highlighted that technology advancements in hydrogen production and fuel cells and the optimization of the manufacturing processes for fuel cell systems are equally essential in the development of hydrogen FCVs.

Among the alternative fuels enabling the energy transition hydrogen-based transportation is a sustainable and efficient choice. It finds application both in light-duty and heavy-duty mobility. However hydrogen gas has unique qualities that must be taken into account when employed in such vehicles: high-pressure levels up to 900 bar storage in composite tanks with a temperature limit of 85 ◦C and a negative Joule–Thomson coefficient throughout a wide range of operational parameters. Moreover to perform a refueling procedure that is closer to the driver’s expectations a fast process that requires pre-cooling the gas to −40 ◦C is necessary. The purpose of this work is to examine the major phenomena that occur during the hydrogen refueling process by analyzing the relevant theory and existing modeling methodologies.