Production & Supply Chain

Solar energy is now one of the most affordable and widely available energy sources. However densely populated cities like Hong Kong often lack the land needed for large-scale solar deployment. Floating solar photovoltaics (FPV) offer a promising alternative by using water surfaces such as reservoirs while providing additional benefits over ground-mounted systems including competition with urban development such as housing and infrastructure. The advantage of this system has been explored in parts of the world while Hong Kong is yet to fully exploit it despite the presence of pilot projects. This study uses PVsyst to evaluate FPV deployment across Hong Kong’s reservoirs estimating over 7 TWh of potential annual electricity generation. Even with 60 % surface coverage generation reaches 4.6 TWh/year with LCOE between $0.036–$0.038/kWh. In parallel green hydrogen is explored as a clean energy storage solution and alternative transport fuel. By using electricity from FPV systems hydrogen production via electrolysis is assessed through HOMER Pro. Results show annual hydrogen output ranging from 180502 kg to 36310221 kg depending on reservoir size with associated LCOH between $10.2/kg and $19.4/kg. The hydrogen produced could support ongoing hydrogen bus projects and future expansion to other vehicle types as Hong Kong moves toward a hydrogen-based transport system. After coupling the FPV systems with hydrogen-generation units the new LCOEs are found to be between $0.029–4.01/ kWh. Thus suggesting the feasibility of a hydrogen-integrated FPV system in Hong Kong.

This work explores the integration of Proton Exchange Membrane (PEM) electrolysis waste heat with district heating networks (DHN) aiming to enhance the overall energy efficiency and economic viability of hydrogen production systems. PEM electrolysers generate substantial amounts of low-temperature waste heat during operation which is often dissipated and left unutilised. By recovering such thermal energy and selling it to district heating systems a synergistic energy pathway that supports both green hydrogen production and sustainable urban heating can be achieved. The study investigates how the electrolyser’s operating temperature ranging between 50 and 80 ◦C influences both hydrogen production and thermal energy availability exploring trade-offs between electrical efficiency and heat recovery potential. Furthermore the study evaluates the compatibility of the recovered heat with common heat emission systems such as radiators fan coils and radiant floors. Results indicate that valorising waste heat can enhance the overall system performance by reducing the electrolyser’s specific energy consumption and its levelized cost of hydrogen (LCOH) while supplying carbon-free thermal energy for the end users. This integrated approach contributes to the broader goal of sector coupling offering a pathway toward more resilient flexible and resource-efficient energy systems.

Harnessing renewable energy for sustainable hydrogen production is a pivotal step towards a greener future. This study explores integrating solar tower (ST) technology with thermal energy storage and a power cycle to drive a PEM electrolyzer for green hydrogen production. A comprehensive investigation is conducted to evaluate the thermodynamic performance of the integrated system including an exergoeconomic analysis to evaluate and optimize techno-economic performance. Exergy analysis reveals that the main components responsible for 84 % of the total exergy destruction are the ST with 60 % the heat exchanger with 16 % and the electrolyzer with 8 %. The hydrogen production cost varies with operational parameters e.g. increased solar radiation reduces the cost to 4.5 $/kg at 1000 W/m2 . Furthermore the overall system performance is evaluated and monitored using overall effectiveness exergy efficiency and hydrogen production cost for full-day operation at hourly intervals based on the design set operating conditions versus optimized ones using the conjugate optimization. The findings indicate that the optimization improved the average overall effectiveness from 29.3 % to 31.2 % and the average exergy efficiency from 36 % to 40 % while the average hydrogen cost is reduced from 4.6 to 4.3 $/kg.

The use of hydrogen as an energy carrier represents a promising alternative for mitigating climate change. However its practical application requires achieving a high degree of purity throughout the production process. In this study the influence of the type of catalytic support on H2 production via steam glycerol reforming was evaluated with the objective of obtaining syngas with the highest possible H2 concentration. Three types of support were analyzed: two natural materials (zeolite and dolomite) and one metal oxide alumina. Alumina and dolomite were coated with Ni at different loadings while zeolite was only evaluated without Ni. Reforming experiments were carried out at a constant temperature of 850 ◦C with continuous monitoring of H2 CO2 CO and CH4 concentrations. The results showed that zeolite yielded the lowest H2 concentration (51%) mainly due to amorphization at high temperatures and the limited effectiveness of physical adsorption processes. In contrast alumina and dolomite achieved H2 purities of around 70% which increased with Ni loading. The improvement was particularly significant in dolomite owing to its higher porosity and the recarbonation processes of CaO enabling H2 purities of up to 90%.

Natural hydrogen or "white hydrogen" has recently garnered attention as a viable and cost-effective energy resource due to its low-carbon footprint and high energy density positioning it as a key contributor to the transition towards a sustainable low-carbon energy system. This study represents Alberta’s first systematic effort to evaluate natural hydrogen potential in the province using publicly available geological geospatial and gas composition datasets. By mapping hydrogen occurrences against key geological features in the Western Canadian Sedimentary Basin (WCSB) we identify regions with strong geological potential for natural hydrogen generation migration and accumulation while addressing data uncertainties. Within the WCSB formations like the Montney Cardium Bearpaw Manville Belly River McMurray and Lea Park are identified as zones likely for hydrogen generation by prominent mechanisms including hydrocarbon decomposition water-rock reactions with iron-rich sediments and organic pyrolysis. Formation proximity to the underlying Canadian Shield may also suggest potential for basement-derived hydrogen migration via deep-seated faults and shear zones. Salt deposits (Elk Point Group - Prairie evaporites Cold Lake and Lotsberg) and deep shales (e.g. Kaskapau Lea Park Wapiabi) provide effective cap rock potential while reservoirs like porous sandstone (e.g. Dunvegan Spirit River Cardium) and fractured carbonate (e.g. Keg River) formations offer favorable accumulation conditions. Hydrogen occurrences in relation to geological features identify Southern Eastern and West-Central plains as prominent natural Hydrogen generation and accumulation areas. Alberta’s established energy infrastructure as well as subsurface expertise positions it as a potential leader in natural hydrogen exploration. As Alberta’s first systematic investigation this study provides a preliminary assessment of natural hydrogen potential and outlines recommended next steps to guide future exploration and research. Targeted research on specific generation and accumulation mechanisms and source identification through isotopic and geochemical fingerprinting will be crucial for exploration de-risking and viability assessment in support of net-zero emission initiatives.

This study explores the generation of natural hydrogen through the serpentinization of onshore ultramafic rocks highlighting its potential as a clean energy resource. By investigating critical factors such as mineral composition temperature and pressure the research develops an empirical model using multiple regression analysis to predict hydrogen generation rates under varying geological conditions. A novel five-stage volumetric calculation methodology is introduced to estimate hydrogen production from ultramafic rock bodies. The application of this framework to the Giles Complex an ultramafic-mafic intrusion in Australia suggests a hydrogen generation potential of approximately 2.24 × 1013 kg of hydrogen through partial serpentinization. This estimate is based on the assumed mineral composition depth and temperature conditions within the intrusion which influence the extent of serpentinization reactions. The findings demonstrate the significant potential of ultramafic complexes for natural hydrogen production and provide a foundation for advancing natural hydrogen exploration refining predictive models and supporting sustainable energy development.

This study evaluates the feasibility of employing rainwater as an alternative feedstock for hydrogen production via electrolysis. While conventional systems typically rely on high-purity water—such as deionized or distilled variants—these can be cost-prohibitive and environmentally intensive. Rainwater being naturally available and minimally treated presents a potential sustainable alternative. In this work a series of comparative experiments was conducted using a proton exchange membrane electrolyzer system operating with both deionized water and rainwater collected from different Austrian locations. The chemical composition of rainwater samples was assessed through inductively coupled plasma ion chromatography and visual rapid tests to identify impurities and ionic profiles. The electrolyzer’s performance was evaluated under equivalent operating conditions. Results indicate that rainwater in some cases yielded comparable or marginally superior efficiency compared to deionized water attributed to its inherent ionic content. The study also examines the operational risks linked to trace contaminants and explores possible strategies for their mitigation.

Given the economic industrial and environmental value of green dihydrogen (H2) optimization of water electrolysis as a means of producing H2 is essential. Binders are a crucial component of electrocatalysts yet they remain largely underdeveloped with a significant lack of standardization in the field. Therefore targeted research into the development of alternative binder systems is essential for advancing performance and consistency. Binders essentially act as the key to regulating the electrode (support)–catalyst–electrolyte interfacial junctions and contribute to the overall reactivity of the electrocatalyst assembly. Therefore alternative binders were explored with a focus on cost efficiency and environmental compatibility striving to achieve desirable activity and stability. Herein the alkaline hydrogen evolution reaction (HER) was investigated and the sluggish water dissociation step was targeted. Controlled hydrophilic poly(vinyl alcohol)-based hydrogel binders were designed for this application. Three hydrogel binders were evaluated without incorporated electrocatalysts namely PVA145 PVA145-blend-bPEI1.8 and PVA145-blend-PPy. Interestingly the study revealed that the hydrophilicity of the binders exhibited an enhancing effect on the observed activity resulting in improved performance compared to the commercial binder Nafion™. Notably the PVA145 system stands out with an overpotential of 224 mV at−10 mA·cm−2 (geometric) in 1.0 M KOH compared to the 238 mV exhibited by Nafion™. Inclusion of Pt as active material in PVA145 as binder exhibited a synergistic increase in performance achieving a mass activity of 1.174 A.cm−2.mg−1 Pt in comparison to Nafion™’s 0.344 A.cm−2.mg−1 Pt measured at−150 mV vs RHE. Our research aimed to contribute to the development of cost-effective and efficient binder systems stressing the necessity to challenge the dominance of the commercially available binders.

The present work focused on the comparison between HHO and hydrogen electrolyzers in design gas production and various parameters which affect the performance and efficiency of alkaline electrolyzers. The primary goal is to generate the highest possible hydrogen and HHO gas flow rates. Hydrogen and HHO were produced using 3 mm electrode of stainless steel 316L with 224 cm2 surface area. Hydroxy and hydrogen rates were affected by electrolyte content cell connection electric current operating time electrolyte temperature and voltage. Maximum HHO generation values were 1020 1076 1125 and 1175 mL min−1 n at 5 10 15 and 20 g L−1 of sodium hydroxide (NaOH) with supply currents of 15 15.3 15.6 and 16 A respectively. Once it stabilized after 30 min the temperature increased to 26 30 35 and 38 °C respectively and remained there. With currents of 18 18.45 18.7 19.2 19.5 and 19.8 A hydrogen output peak values after 60 min. stayed constant at 680 734 785 846 897 and 945 mL min-1. at 5 10 15 and 20 g L−1 NaOH catalyst concentrations. At 5 10 15 and 20 g L−1 catalyst ratios the temperatures were elevated to constant values of 28.5 32 37.9 40.5 41.4 and 43 °C respectively. With cell design [4C3A19N] electrolyte concentration of 5 g L−1 NaOH and current of 14 A maximum HHO productivity was 866 mL min−1. and 74.23% efficiency. In a cell design of [4C5A17N] with catalyst content of 10 g L−1 maximum productivity was 680 mL min−1 for hydrogen and highest production efficiency of 72.85% was attained at 18 A.

Solid oxide electrolysis (SOEL) is considered an efficient option for largely emission-free hydrogen production and thus for supporting the decarbonization of the process industry. The thermodynamic advantages of high-temperature operation can be utilized particularly when heat integration from subsequent processes is realized. As the produced hydrogen is usually required at a higher pressure level the operating pressure of the electrolysis is a relevant design parameter. The study compares pressurized and near-atmospheric designs of 126 MW SOEL systems with and without the integration of process heat from a downstream ammonia synthesis and the inefficiencies that occur in the processes. Furthermore process improvements by sweep-air utilization are investigated. Pinch analysis is applied to determine the potential of internal heat recovery and the minimum external heating and cooling demand. It is shown that pressurized SOEL operation does not necessarily decrease the overall power consumption for compression due to the high power requirement of the sweep-air compressor. The exergetic efficiencies of the standalone SOEL processes achieve similar values of = 81 %. Results further show that integrating the heat of reaction from ammonia synthesis can replace almost the entire electrically supplied thermal energy thereby improving the overall exergetic efficiency by up to 3.5 percentage points. However the exergetic efficiency strongly depends on the applied air ratio. The highest exergetic efficiency of 86 % can be achieved by employing sweep-air utilization with an expander. The results demonstrate that integrating downstream process heat and applying sweep-air utilization can significantly enhance overall efficiency and thus reduce external energy requirements.