Publications

This study presents an enhancement to the Switch optimization model for hydrogen energy planning by integrating the capability to consider the construction and operation of hydrogen electrolysis plants and the operation of water distribution systems. This integration was achieved through the addition of two new modules and their effectiveness is demonstrated through their application in a case study for Durham region. The study highlights the significance of incorporating water distribution systems into energy planning demonstrating how optimal locations for hydrogen plants can significantly influence water and power demand as well as alter the total operating costs. The enhanced Switch model showcases its improved capability to assist policymakers and stakeholders in transitioning towards a sustainable energy future.

In the global content regarding the impact on the environmental of the gases emissions resulted from the fossil fuels combustion aspect discussed on the 2015 Paris Climate Conference contribute to the necessity of searching of alternative energy from durable and renewable resources. The purpose of the paper is the use of hydrogen fuelling at truck diesel engine in order to improves engine efficiency and pollutant performance hydrogen being injected into the inlet manifold. Experimental results show better energetic and pollution performance of the dual fuelled engine due to the improvement of the combustion process and reduction of carbon content.

Water electrolysis is the most promising method for efficient production of high purity hydrogen (and oxygen) while the required power input for the electrolysis process can be provided by renewable sources (e.g. solar or wind). The thus produced hydrogen can be used either directly as a fuel or as a reducing agent in chemical processes such as in Fischer–Tropsch synthesis. Water splitting can be realized both at low temperatures (typically below 100 °C) and at high temperatures (steam water electrolysis at 500– 1000 °C) while different ionic agents can be electrochemically transferred during the electrolysis process (OH− H+ O2− ). Singular requirements apply in each of the electrolysis technologies (alkaline polymer electrolyte membrane and solid oxide electrolysis) for ensuring high electrocatalytic activity and long-term stability. The aim of the present article is to provide a brief overview on the effect of the nature and structure of the catalyst–electrode materials on the electrolyzer’s performance. Past findings and recent progress in the development of efficient anode and cathode materials appropriate for large-scale water electrolysis are presented. The current trends limitations and perspectives for future developments are summarized for the diverse electrolysis technologies of water splitting while the case of CO2/H2O co-electrolysis (for synthesis gas production) is also discussed.

Hydrogen as an energy source has been identified as an optimal pathway for mitigating climate change by combining renewable electricity with water electrolysis systems. Proton exchange membrane (PEM) technology has received a substantial amount of attention because of its ability to efficiently produce high-purity hydrogen while minimising challenges associated with handling and maintenance. Another hydrogen generation technology alkaline water electrolysis (AWE) has been widely used in commercial hydrogen production applications. Anion exchange membrane (AEM) technology can produce hydrogen at relatively low costs because the noble metal catalysts used in PEM and AWE systems are replaced with conventional low-cost electrocatalysts. Solid oxide electrolyzer cell (SOEC) technology is another electrolysis technology for producing hydrogen at relatively high conversion efficiencies low cost and with low associated emissions. However the operating temperatures of SOECs are high which necessitates long startup times. This review addresses the current state of technologies capable of using impure water in water electrolysis systems. Commercially available water electrolysis systems were extensively discussed and compared. The technical barriers of hydrogen production by PEM and AEM were also investigated. Furthermore commercial PEM stack electrolyzer performance was evaluated using artificial river water (soft water). An integrated system approach was recommended for meeting the power and pure water demands using reversible seawater by combining renewable electricity water electrolysis and fuel cells. AEM performance was considered to be low requiring further developments to enhance the membrane’s lifetime.

The necessity of energy solutions that are economically viable ecologically sustainable and environmentally friendly has become fundamental to economic and societal advancement of nations. In this context renewable energy sources emerge as the most vital component. Furthermore hydrogen generation systems based on renewable energies are increasingly recognized as the most crucial strategies to mitigate global warming. In the present study a comparative analysis is conducted from an exergy-economic perspective to find the most efficient configuration among three different systems for renewable-based power to hydrogen production. These renewable sources are wind turbine salinity gradient solar pond (SGSP) and ocean thermal energy conversion (OTEC). SGSP and OTEC are coupled with a hydrogen production unit by a trilateral cycle (TLC) to improve the temperature match of the heating process. The heat waste energy within these systems is recovered by a thermoelectric generator (TEG) and a proton exchange membrane electrolyzer (PEME) is used for hydrogen production. Under base case input conditions the net power input of PEME is estimated to be approximately 327.8 kW across all configurations. Additionally the 3E (energy exergy and exergy-economic) performance of the three systems is evaluated by a parametric study and design optimization. The results of the best performance analysis reveal that the best exergy efficiency is achievable with the wind-based system in the range of 5.8–10.47% and for average wind speed of 8–12 m/s. Correspondingly the most favorable total cost rate is attributed to the wind-based system at a wind speed of 8 m/s equating to 66.08 USD/h. Subsequently the unit cost of hydrogen for the SGSP-based system is estimated to be the most economical ranging from 42.78 to 44.31 USD/GJ.

The transportation sector is a significant source of greenhouse gas emissions. Electric vehicles (EVs) have gained popularity as a solution to reduce emissions but the high load of charging stations poses a challenge to the power grid. Nuclear-Renewable Hybrid Energy Systems (N-RHES) present a promising alternative to support fast charging stations reduce grid dependency and decrease emissions. However the intermittent problem of renewable energy sources (RESs) limits their application and the synergies among different technologies have not been fully exploited. This paper proposes a predictive and adaptive control strategy to optimize the energy management of N-RHES for fast charging stations considering the integration of nuclear photovoltaics and wind turbine energy with a hydrogen storage fuel cell system. The proposed dynamic model of a fast-charging station predicts electricity consumption behavior during charging processes generating probabilistic forecasting of electricity consumption time-series profiling. Key performance indicators and sensitivity analyses illustrate the practicability of the suggested system which offers a comprehensive solution to provide reliable sustainable and low-emission energy to fast-charging stations while reducing emissions and dependency on the power grid.

This study evaluates the levelised cost of hydrogen (LCOH) dynamically produced using the two dominant electrolysis technologies directly connected to wind turbines or photovoltaic (PV) panels in regions of Australia designated as hydrogen hubs. Hourly data are utilised to size the components required to meet the hydrogen demand. The dynamic efficiency of each electrolysis technology as a function of input power along with its operating characteristics and overload capacity are employed to estimate flexible hydrogen production. A sensitivity analysis is then conducted to capture the behaviour of the LCOH in response to inherent uncertainty in critical financial and technical factors. Additionally the study investigates the trade-offs between carbon cost and lifecycle emissions of green hydrogen. This approach is applied to ascertain the impact of internalising environmental costs on the cost-competitiveness of green hydrogen compared to grey hydrogen. The economic modelling is developed based on the Association for the Advancement of Cost Engineering (AACE) guidelines. The findings indicate that scale-up is key to reducing the LCOH by a meaningful amount. However scale-up alone is insufficient to reach the target value of AUD 3 (USD 2) except for PV-based plant in the Pilbara region. Lowered financial costs from scale-up can make the target value achievable for PV-based plants in Gladstone and Townsville and for wind-based plants in the Eyre Peninsula and Pilbara regions. For other hubs a lower electricity cost is required as it accounts for the largest portion of the LCOH.

Electrification of the transportation sector is one of the main drivers in the decarbonization of energy and mobility systems and it is a way to ensure security of energy supply. Public bus fleets can assist in achieving fast reduction of CO2 emissions. This article provides an analysis of a unique real-world dataset to support decision makers in the decarbonization of public fleets and interlink it with the social acceptance of drivers. Data was collected from 21 fuel cell and electric buses. The tank-to-wheel efficiency results of fuel cell electric buses (FCEB) are much lower than that of battery electric buses (BEB) and there is a higher variation in consumption for BEBs compared to FCEBs. Both technologies permit a strong reduction in CO2 emissions compared to conventional buses. There is a high level of acceptance of drivers which are likely to support the transition towards zero-emission buses introduced by the management.

This study describes the optimization of a modelling process concerning biogas’ use to generate green hydrogen and electrical power. The Aspen Plus simulation tool is used to model the procedure and the approach employed to limit the emissions of gas from the hydrogen production process will be the CO2 capture method. This technique uses slack lime (Ca(OH)2) to absorb CO2 capture since it is readily available. The study analyzes many critical parameters in the process including the temperature and pressure in the steam reforming (SR) and the water gas shift (WGS) reactions along with the steam to carbon ratio (S/C) to determine how the production of green hydrogen and electrical power will be influenced. Electricity generation is achieved by taking the residual water from the SR WGS carbonation reactions and converting it to the vapour phase allowing the steam to pass through the turbine to generate electricity. To examine the effects of the synchronized critical parameters response surface methodology (RSM) was used thus allowing the optimal operational conditions to be determined in the form of an optimized zone for operation. The result of parameter optimization gave the maximum green hydrogen production of 211.46 kmol/hr and electric power production of 2311.68 kWh representing increases of 34.86% and 5.62% respectively when using 100 kmol/hr of biogas. In addition control structures were also built to control the reactors’ temperature in the dynamic section. The tuning parameters can control the SR and WGS system’s reactor to maintain the system in approximately 0.29 h and 0.32 h respectively.

The use of hydrogen fuel produced from renewable energy sources is an effective way to reduce well-to-wheel CO2 emissions from automobiles. In this study the performance of a hydrogen-powered series hybrid vehicle was compared with that of other powertrains such as gasoline-powered hybrid fuel cell and electric vehicles in a simulation that could estimate CO2 emissions under real-world driving conditions. The average fuel consumption of the hydrogenpowered series hybrid vehicle exceeded that of the gasoline-powered series hybrid vehicle under all conditions and was better than that of the fuel cell vehicle under urban and winding conditions with frequent acceleration and deceleration. The driving range was longer than that of the batterypowered vehicle but approximately 60% of that of the gasoline-powered series hybrid. Regarding the life-cycle assessment of CO2 emissions fuel cell and electric vehicles emitted more CO2 during the manufacturing process. Regarding fuel production CO2 emissions from hydrogen and electric vehicles depend on the energy source. However in the future this problem can be solved by using carbon-free energy sources for fuel production. Therefore hydrogen-powered series hybrid vehicles show a high potential to be environmentally friendly alternative fuel vehicles.