Australia

Mobility has been a prominent target for proponents of the hydrogen economy. Given the complexities involved in the mobility value chain actors hoping to participate in this nascent market must overcome a range of challenges relating to the availability of vehicles the co-procurement of supporting infrastructure a favourable regulatory environment and a supportive community among others. In this paper we present a state-of-play account of the nascent hydrogen mobility market in Victoria Australia drawing on data from a workshop (N ¼ 15) and follow-up interviews (n ¼ 10). We interpret findings through a socio-technical framework to understand the ways in which fuel cell electric vehicles (FCEVs)dand hydrogen technologies more generallydare conceptualised by different stakeholder groups and how these conceptualisations mediate engagement in this unfolding market. Findings reveal prevailing efforts to make sense of the FCEV market during a period of considerable institutional ambiguity. Discourses embed particular worldviews of FCEV technologies themselves in addition to the envisioned roles the resultant products and services will play in broader environmental and energy transition narratives. Efforts to bring together stakeholders representing different areas of the FCEV market should be seen as important enablers of success for market participants.

Hydrogen is emerging as a promising future energy medium in a wide range of industries. For mobile applica tions it is commonly stored in a gaseous state within high-pressure composite overwrapped pressure vessels (COPVs). The current state of the art pressure vessel technology known as Type V eliminates the internal polymer gas barrier used in Type IV vessels and instead relies on carbon fibre laminate to provide structural properties and prevent gas leakage. Achieving this functionality at high pressure poses several engineering challenges that have thus far prohibited commercial application. Additionally the traditional manufacturing process for COPVs filament winding has several constraints that limit the design space. Automated fibre placement (AFP) a highly flexible robotic composites manufacturing technique has the potential to replace filament winding for composite pressure vessel manufacturing and provide pathways for further vessel optimi sation. A combination of both AFP and Type V technology could provide an avenue for a new generation of highperformance composite pressure vessels. This critical review presents key work on industry-standard Type IV vessels alongside the current state of Type V CPV technology including manufacturing developments challenges cost relevance to commercial standards and future fabrication solutions using AFP. Additionally a novel Type V CPV design concept for a two-piece AFP produced vessel is presented.

We perform a simulation study of hydrogen injection in a depleted gas reservoir to assess the geomechanical impact of hydrogen storage relative to other commonly injected gases (methane CO2). A key finding is that the differences in hydrogen density compressibility viscosity and thermal properties compared to the other gases result in significantly less thermal perturbation at reservoir level. The risks of fault reactivation and wellbore fractures due to thermally-induced stress changes are significantly lower when storing hydrogen compared to results observed in CO2 scenarios. This implies that hydrogen injection and production has a much smaller geomechanical footprint with benefits for operational safety. We also find that use of nitrogen cushion gas ensures efficient deliverability and phase separation in the reservoir. However in this study a large fraction of cushion gas was back-produced in each cycle demonstrating the need for further studies of the surface processing requirements and economic implications.

Introduction: An online deliberative engagement process was undertaken with members of the general public to understand what they value or would like to change about the energy system within the broader context of decarbonizing Australia's energy networks identifying a role for future fuels (hydrogen and biogas). Citizens developed a set of principles that could guide Australia's path toward a low-carbon energy future reflecting on expectations they place upon energy transition. Next citizens' principles were shared with policy-makers in government and policy-influencers from the energy industry using an online interactive workshop.<br/>Methods: This study analyses policy-makers and -influencers response to citizens' guiding principles using the 'diamond of participatory decision-making' framework for analysis. Convergence and divergence in diverse complex and rich views across cohorts and implications thereupon energy policy were identified.<br/>Results: Although considerable alignment between multi-stakeholders' views was noted key areas of divergence or what is called the “groan zone” were easily identified in relation to social and environmental justice issues. This groan zone highlights the struggles that energy policy-makers face -the need to listen and respond to citizens' voices vs. the need for practical and workable policies that also support overarching government or industry objectives.<br/>Discussion: Policy making when the views of different stakeholders align is relatively straightforward. However this is not the case where the expectations diverge. More creative measures will be needed to address divergent views and expectations whilst maintaining procedural fairness in this case using democratic deliberative engagement processes. While the use of deliberative processes is gaining momentum worldwide particularly concerning climate change and energy transition policies this paper also highlights the benefits of conducting a robust post facto analysis of the content of the processes. Areas of alignment where policy can be made and implemented relatively easily without contention are identified. Other areas (such as making electrification mandatory) might be more complex or have unwanted negative social and environmental justice effects. Overall this paper bridges an analytical gap between “expectation studies” and participatory research. By borrowing terminology from a participatory research framework we sharpen the concepts in “expectation studies” from a consensus inclusion and diversity standpoint.

In today’s world the need for sustainable energy solutions is paramount to address the ongoing crisis of increasing greenhouse gas emissions and global warming. Industries heavily reliant on fossil fuels must explore alternative energy sources. Hydrogen with its high heating value and zero direct emissions has emerged as a promising fuel for the future. Electrolytic hydrogen production has gained significance as it enables demand-side response grid stabilization using excess energy and the mitigation of curtailment from intermittent renewable energy sources (RES) such as solar and wind. Advanced combined heat and power (CHP) systems comprise of Solid oxide fuel cell (SOFC) module and a coupled reforming reactor to capture energy contained in the SOFC exhaust gases from SOFC. In present work 3D CFD model of an experimental coupled reactor used for onsite hydrogen production is developed and implemented into ANSYS Fluent® software. The study is aimed at opti mizing the reactor performance by identifying appropriate kinetic models for reforming and combustion re actions. SOFC anode off-gas (AOG) comprising mainly of unconverted hydrogen is combined with methane combustion to enhance thermal efficiency of the reactor and hence the CHP system. Kinetic models for catalytic reforming and combustion are implemented into ANSYS Fluent® through custom-built user defined functions (UDFs) written in C programming language. Simulation results are validated with experimental data and found in good agreement. AOG assisted combustion of methane shows a substantial improvement in thermal efficiency of the system. Improvement in thermal efficiency and reduction in carbon-based fuel demand AOG utilization contributes to sustainable hydrogen production and curtailment of greenhouse gas emissions.