Applications & Pathways

China has pledged that it will strive to achieve peak carbon emission by 2030 and realize carbon neutrality by 2060 which has spurred renewed interest in hydrogen for widespread decarbonization of the economy. Hydrogen energy is an important secondary clean energy with the advantage of high density high calorific value rich reserves extensive sources and high conversion efficiency that can be widely used in power generation transportation fuel and other fields. In recent years with the guidance of policies and the progress of technology China’s hydrogen energy industry has developed rapidly. About 42% of China’s carbon emissions comes from the power system and Shenzhen has the largest urban power grid in China. Bringing the utilization of hydrogen energy into Shenzhen’s power system is an important method to achieve industry transformation achieve the “double carbon” goal and promote sustainable development. This paper outlines the domestic and international development status of hydrogen energy introduces the characteristics of Shenzhen new power system the industrial utilization of hydrogen energy and the challenges of further integrating hydrogen energy into Shenzhen new power system and finally suggests on the integration of hydrogen energy into Shenzhen new power system in different dimensions.

Wind curtailment and weak inertia characteristics are two factors that shackle the permeability of wind power. An electric hydrogen production device consumes electricity to produce hydrogen under normal working conditions to solve the problem of abandoning wind. When participating in frequency regulation it serves as a load reduction method to assist the system to rebuild a power balance and improve the wind power permeability. However due to its own working characteristics an electric hydrogen production device cannot undertake the high-frequency component of the frequency regulation power command; therefore an energy storage device was selected to undertake a high-frequency power command to assist the electric hydrogen production device to complete the system frequency regulation. This paper first proposes and analyzes the architecture of a wind storage hydrogen-generating station for centralized hydrogen production with a distributed energy storage and proposes the virtual inertia and droop characteristic mechanism of the wind storage hydrogen-generating station to simulate a synchronous unit. Secondly an alkaline electrolysis cell suitable for large-scale engineering applications is selected as the research object and its mathematical model is established the matching between different energy storage devices and their cooperation in power grid frequency regulation is analyzed and a super capacitor is selected. A control strategy for the wind storage hydrogen-generating power station to participate in power grid frequency regulation with a wide time scale is then proposed. Using the first-order low-pass filter the low-frequency component of the frequency regulation power command is realized by an electric hydrogen production device load reduction and a high-frequency component is realized by the energy storage device. Finally the effectiveness and rationality of the proposed control strategy are verified by establishing the simulation model of the wind storage hydrogen-generating power station with different initial wind speed states comparing the system frequency dip values under the proposed multi-energy cooperative control strategy and a single energy device control strategy.

The free-piston engine is a type of none-crank engine that could be operated under variable compression ratio and this provides it flexible fuel applicability and low engine emission potential. In this work several 1-D engine models including conventional gasoline engines free-piston gasoline engines and free-piston hydrogen engines have been established. Both engine performance and emission performance under engine speeds between 5–11 Hz and with different equivalent ratios have been simulated and compared. Results indicated that the free-piston engine has remarkable potential for NOx reduction and the largest reduction is 57.37% at 6 Hz compared with a conventional gasoline engine. However the figure of NOx from the hydrogen free-piston engine is slightly higher than that of the gasoline free-piston engine and the difference increases with the increase of engine speed. In addition several factors and their relationships related to hydrogen combustion in the free-piston engine have been investigated and results show that the equivalent ratio ϕ = 0.88 is a vital point that affects NOx production and the ignition advance timing could also affect combustion duration the highest in-cylinder temperature and NOx production to a large extent.

Fuel cell electric vehicles (FCEV) are developing quickly from passenger vehicles to trucks or fork-lifts. Policymakers are supporting an ambitious strategy to deploy fuel cell electrical vehicles with infrastructure as hydrogen refueling stations (HRS) as the European Green deal for Europe. The hydrogen fuel quality according to international standard as ISO 14687 is critical to ensure the FCEV performance and that poor hydrogen quality may not cause FCEV loss of performance. However the sampling system is only available for nozzle sampling at HRS. If a FCEV may show a lack of performance there is currently no methodology to sample hydrogen fuel from a FCEV itself. It would support the investigation to determine if hydrogen fuel may have caused any performance loss. This article presents the first FCEV sampling system and its comparison with the hydrogen fuel sampling from the HRS nozzle (as requested by international standard ISO 14687). The results showed good agreement with the hydrogen fuel sample. The results demonstrate that the prototype developed provides representative samples from the FCEV and can be an alternative to determine hydrogen fuel quality. The prototype will require improvements and a larger sampling campaign.

Increasing sales of conventional fuel-based vehicles are leading to an increase in carbon emissions which are dangerous to the environment. To reduce these conventional fuel-based vehicles must be replaced with alternative fuel vehicles such as hydrogen-fueled. Hydrogen can fuel vehicles with near-zero greenhouse gas emissions. However to increase the penetration of such alternative fuel vehicles there needs to be adequate infrastructure specifically refueling infrastructure in place. This paper presents a comprehensive review of the different optimization strategies and methods used in the location of hydrogen refueling stations. The findings of the review in this paper show that there are various methods which can be used to optimally locate refueling stations the most popular being the p-median and flow-capture location models. It is also evident from the review that there are limited studies that consider location strategies of hydrogen refueling stations within a rural setting; most studies are focused on urban locations due to the high probability of penetration into these areas. Furthermore it is apparent that there is still a need to incorporate factors such as the safety elements of hydrogen refueling station construction and for risk assessments to provide more robust realistic solutions for the optimal location of hydrogen refueling stations. Hence the methods reviewed in this paper can be used and expanded upon to create useful and accurate models for a hydrogen refueling network. Furthermore this paper will assist future studies to achieve an understanding of the extant studies on hydrogen refueling station and their optimal location strategies.

Extensive decarbonisation efforts result in major changes in energy demand for the extractive industry. In 2021 the extraction and primary processing of metals and minerals accounted for 4.5 Gt of CO2 eq. per year. The aluminium industry was responsible for 1.1 Gt CO2 eq. direct and indirect emissions. To reach the European milestone of zero emissions by 2050 a reduction of 3% annually is essential. To this end the industry needs to take a turn towards less impactful production practices coupling secondary production with green energy sources. The present work aims to comprehensively compare the lifecycle energy consumption and environmental performance of a secondary aluminium smelter employing alternative thermal and electricity sources. In this frame a comparative analysis of the environmental impact of different thermal energy sources namely natural gas light fuel oil liquified petroleum gas hydrogen and electricity for a secondary aluminium smelter is presented. The results show that H2 produced by renewables (green H2 ) is the most environmentally beneficial option accounting for −84.156 kg CO2 eq. By producing thermal energy as well as electricity on site H2 technologies also serve as a decentralized power station for green energy production. These technologies account for a reduction of 118% compared to conventionally used natural gas. The results offer a comprehensive overview to aid decision-makers in comparing environmental impacts caused by different energy sources.

This report sets out progress against our strategic framework for decarbonising aviation as well as the latest aviation emissions data and updated Jet Zero analysis.<br/>Among the significant milestones achieved since the Jet Zero strategy launch are the:<br/>- agreement at the International Civil Aviation Organization for a long-term aspirational goal for aviation of net zero 2050 carbon dioxide (CO2) emissions for international aviation<br/>- publication of the 2040 zero emissions airport target call for evidence<br/>significant progress on sustainable aviation fuels (SAF) including:<br/>- publishing the second SAF mandate consultation<br/>- launching a second round of the Advanced Fuels Fund<br/>- publishing the Philip New report and the government response on how to develop a UK SAF industry<br/>- publication of the government response to the UK ETS consultation setting out a range of commitments that will enhance the effectiveness of the UK Emissions Trading Scheme (ETS) for aviation<br/>- launch of the expressions of interest for 2 DfT- funded research projects into aviation’s non-CO2 impacts<br/>The report also acknowledges that big challenges remain and we need to continue to work across the aviation sector and with experts across the economy to ensure we continue to make progress on our path to decarbonise aviation.

Gaseous hydrogen for fuel cell electric vehicles must meet quality standards such as ISO 14687:2019 which contains maximal control thresholds for several impurities which could damage the fuel cells or the infrastructure. A review of analytical techniques for impurities analysis has already been carried out by Murugan et al. in 2014. Similarly this document intends to review the sampling of hydrogen and the available analytical methods together with a survey of laboratories performing the analysis of hydrogen about the techniques being used. Most impurities are addressed however some of them are challenging especially the halogenated compounds since only some halogenated compounds are covered not all of them. The analysis of impurities following ISO 14687:2019 remains expensive and complex enhancing the need for further research in this area. Novel and promising analyzers have been developed which need to be validated according to ISO 21087:2019 requirements.

The decreasing abundance of conventional energy resources of nature such as crude oil natural gas and coal is putting forward the issues of energy shortcoming for the future. With a sentiment of this most researchers are now directing either on non-conventional resources that already prevail or invent it. The most promising non-conventional energy resource is the hydrogen energy which can be used in fuel cell to get electricity. Therefore a number of researchers are putting a light on developing the most efficient and affordable fuel cell. This review is mainly focused on the developments of proton exchange membranes (PEMs) in two parts as low and high temperature PEMs for proton exchange membrane fuel cell (PEMFC) and based on that some outperformed PEMs are mentioned in the respective tables. Most of the energy and automobile industries are concentrating to apply PEMFCs for power generation and to apply in vehicles. The cost of PEMFCs is higher due to the manufacturing cost of PEM. Therefore research works in PEMs are now in trend to reduce the cost to improve efficiency and to withstand particular operating conditions. In this review article recent developments in PEM by number of researchers and the importance of it in near future have been elicited.

Currently renewable energy-based generators are considered worldwide to achieve net zero targets. However the stochastic nature of renewable energy systems leads to regulation and control challenges for power system operators especially in remote and regional grids with smaller footprints. A hybrid system (i.e. solar wind biomass energy storage) could minimise this issue. Nevertheless the hybrid system is not possible to develop in many islands due to the limited land area geographical conditions and others. Hydrogen as a carrier of clean energy can be used in locations where the installation of extensive or medium-scale renewable energy facilities is not permissible due to population density geographical constraints government policies and regulatory issues. This paper presents a techno-economic assessment of designing a green hydrogen-based microgrid for a remote island in North-east Australia. This research work determines the optimal sizing of microgrid components using green hydrogen technology. Due to the abovementioned constraints the green hydrogen production system and the microgrid proposed in this paper are located on two separate islands. The paper demonstrates three cost-effective scenarios for green hydrogen production transportation and electricity generation. This work has been done using Hybrid Optimisation Model for Multiple Energy Resources or HOMER Pro simulation platform. Simulation results show that the Levelized Cost of Energy using hydrogen technology can vary from AU$0.37/kWh to AU$1.08/kWh depending on the scenarios and the variation of key parameters. This offers the potential to provide lower-cost electricity to the remote community. Furthermore the CO2 emission could be reduced by 1760777 kg/year if the renewable energy system meets 100% of the electricity demand. Additionally the sensitivity analysis in this paper shows that the size of solar PV and wind used for green hydrogen production can further be reduced by 50%. The sensitivity analysis shows that the system could experience AU$0.03/kWh lower levelized cost if the undersea cable is used to transfer the generated electricity between islands instead of hydrogen transportation. However it would require environmental approval and policy changes as the islands are located in the Great Barrier Reef.