Stuart D. C. Walsh

As global momentum builds toward decarbonisation, green hydrogen has emerged as a key pillar in Australia’s transition to a net-zero emissions future. However, the freshwater demands of large-scale electrolysis poses a significant social hurdle, particularly in a nation facing acute water scarcity. The SeaHydrogen approach, developed in the Netherlands, offers a potential solution by using waste heat from the electrolysis process to desalinate seawater via membrane distillation, enabling hydrogen production without drawing on limited freshwater supplies. This paper investigates the techno-economic feasibility of using membrane distillation as the desalination method for green hydrogen production, when compared to conventional reverse osmosis. The Arrowsmith Hydrogen Project in Western Australia was used as a case study to link the investigation to real world applications. Hydrogen electrolysis requires significant volumes of purified water, posing challenges in water-scarce regions such as regional Australia. Eight scenarios were modelled using brackish aquifer and seawater sources to evaluate capital expenditure, operational expenditure, levelised cost of water, and net present value for both desalination technologies. Results showed that membrane distillation achieved lower levelised cost of water values than reverse osmosis across all configurations (with reductions in cost between 15–37% for the cases considered). This was primarily due to its ability to utilise low-grade waste heat from electrolysers, substantially reducing energy demand and operational expenditure. Aquifer-sourced membrane distillation emerged as the most economically viable configuration. Integrated membrane distillation also presents other potential benefits, including lower energy intensity, reduced-liquid discharge, improved waste-heat recovery, and the option to produce a limited volume of surplus distilled water, either for on-site use or to supplement small local communities. The findings highlight membrane distillation as a promising alternative to reverse osmosis for sustainable hydrogen production, consistently delivering water for lower cost for the Arrowsmith site. Moreover the analysis shows that both methods can be used to generate excess potable water at prices that are competitive with existing water supplies.

Australia is the world’s largest iron ore exporter and is well positioned to be a major producer of hydrogen-based direct reduced iron (DRI) and steel, given its vast iron ore deposits and abundant renewable energy. However, the mid-grade of the majority of Australian hematite makes the commercially demonstrated electric arc furnace (DRI-EAF) route unsuitable without extensive beneficiation. An alternative pathway using electric smelting furnace and basic oxygen furnace (DRI-ESF-BOF) may allow the direct use of high gangue ores. However, the intermittency of renewables presents a challenge to plants which rely on baseload power. New DRI shaft furnace (DRI-SF) technologies may allow load flexibility, reducing renewable capacity overbuild and firming. This study investigated the value of load flexibility (VoF) of the DRI-SF within an integrated steel plant, considering mid and high grade ore pathways. Enabling DRI-SF flexibility can reduce the levelised cost of steel (LCoS) by 25\% - 36\%, driven by reductions in solar, wind and hydrogen build-out. DRI-SF load flexibility allows deeper flexibility of the electrolyser, which become apparent during periods of renewable drought. As flexibility increases, dependence on hydrogen storage declines, with hot-briquetted iron (HBI) storage increasingly providing seasonal buffering. At full flexibility, cost parity can be achieved between the mid and high grade ore routes. Site selection significantly influences LCoS and VoF, with multiple regions were achieving LCoS as low as A\$1,100 per tonne. These findings have implications for Australia’s green steel strategy and the viability of mid and high grade ore pathways, and countries facing similar challenges in ore quality, renewable variability, and hydrogen-based industrial decarbonisation.

This study evaluates the adoption and efficacy of the 5th Dimension Building Information Modelling (5D-BIM) as a cost dimension for mega rail projects, extending the discussion beyond just technological implementation to consider broader policy and practical implications. The purpose of this article is to understand the governance context of 5D-BIM implementation for rail and transport projects and evaluate the effectiveness of the 5D-BIM framework as currently applied by conducting semi-structured interviews with key stakeholders. Drawing on semi-structured interviews with 22 stakeholders across government, industry, and technology providers, the research examines current 5D-BIM practices. While the primary focus of the research is 5D BIM implementations within the state of Victoria, Australia, which is currently experiencing a surge in rail projects, interviews were also conducted with additional stakeholders from international rail projects for context. The findings reveal fragmented adoption, varying levels of organisational maturity, and significant policy and implementation gaps, particularly in the role of government as the primary client of transport infrastructure. The results of the interviews emphasise the centrality of government and regulatory context in driving the adoption and implementation of 5D-BIM as the primary client of transportation infrastructure and identify actionable recommendations for policymakers and practitioners towards a more integrated approach to 5D-BIM in mega rail projects. While 5D-BIM demonstrates clear benefits in enhancing cost estimation, coordination, and decision-making, its effectiveness is constrained by the absence of clear standards, limited BIM literacy, and inconsistent regulatory guidance. This study provides one of the first empirical validations of the 5D-BIM governance framework, demonstrating that its success is driven less by technological capability and more by policy alignment, standardisation, and institutional leadership.

Integration of 5D Building Information Modeling (BIM) into large rail projects has the potential to significantly enhance cost management and control. Nevertheless, 5D-BIM implementation has encountered difficulties stemming from technical, functional, and governance-related factors. This paper builds a conceptual framework to support financial decision making, enhances project management, and promotes efficient project delivery. The framework encompasses a set of interrelated elements that include project governance, BIM policies and standards, digital platforms, BIM LOD, cost-estimation classification, and continuous improvement. The proposed framework acknowledges the significance of project governance in guiding and organizing the implementation of 5D-BIM. Additionally, BIM policies and standards ensure the adherence to quality standards for the produced BIM models. Digital platforms serve as the basis for multiple users to generate, access, share, and exchange project information. BIM LOD promotes collaboration and coordination among all project stakeholders. Cost-estimation classification aligns the estimation process with the development of project scope and financial decision making. Continuous improvement plays a vital role in optimizing processes, enhancing efficiency, and achieving higher-quality outcomes. Moreover, it fosters stakeholder satisfaction, improves project performance, and nurtures a conducive environment for innovation and learning. The study analyzes the framework utilization in Victorian rail projects and identifies key implementation challenges. The main technical hurdles encountered were the lack of current horizontal infrastructure standards for data exchange and the lack of compatibility with current cost-management standards. Increased project complexity and the absence of clear project governance strategies and processes also posed organizational challenges. A further validation of the framework in real-world rail projects was recommended to achieve the implementation goals.

Integration of 5D Building Information Modelling (BIM) into large rail projects has the potential to significantly enhance cost management and control. Nevertheless, 5D-BIM implementation has encountered difficulties stemming from technical, functional, and governance-related factors. This paper builds a conceptual framework to support financial decision-making, enhances project management, and promotes efficient project delivery. The framework encompasses a set of interrelated elements that include project governance, BIM policies and standards, digital platforms, BIM LOD, cost estimation classification, and continuous improvement. The proposed framework acknowledges the significance of project governance in guiding and organizing the implementation of 5D-BIM. Additionally, BIM policies and standards ensure the adherence to quality standards for the produced BIM models. Digital platforms serve as the basis for multiple users to generate, access, share, and exchange project information. BIM LOD promotes collaboration and coordination among all project stakeholders. Cost estimation classification aligns the estimation process with the development of project scope and financial decision-making. Continuous improvement plays a vital role in optimizing processes, enhancing efficiency, and achieving higher-quality outcomes. Moreover, it fosters stakeholder satisfaction, improves project performance, and nurtures a conducive environment for innovation and learning. The study analyses the framework utilization in the Victorian rail projects and identifies key implementation challenges. This can be summed up as follows: The main technical hurdles were the lack of current horizontal infrastructure standards for data exchange and the lack of compatibility with current cost management standards. Increased project complexity and the absence of clear project governance strategies and processes posed organizational challenges. A further validation of the framework in real-world rail projects was recommended to achieve the implementation goals.