Applications & Pathways

Hydrogen is considered one of the key pillars of an effective decarbonization strategy of the energy sector; however the potential of hydrogen as an electricity storage medium is debated. This paper investigates the role of hydrogen as an electricity storage medium in an electricity system with large hydropower resources focusing on the Swiss electricity sector. Several techno-economic and climate scenarios are considered. Findings suggest that hydrogen storage plays no major role under most conditions because of the large hydropower resources. More specifically no hydrogen storage is installed in Switzerland if today’s values of net-transfer capacities and low load-shedding costs are assumed. This applies even to hydrogen-favorable climate scenarios (dry years with low precipitation and dam inflows) and economic assumptions (high learning rates for hydrogen technologies). In contrast hydrogen storage is installed when net-transfer capacities between countries are reduced below 30% of current values and load-shedding costs are above 1000 EUR/MWh. When installed hydrogen is deployed in a few large-scale installations near the national borders.

A multi-objective optimization is performed to obtain fueling conditions in hydrogen stations leading to improved filling times and thermodynamic efficiency (entropy production) of the de facto standard of operation which is defined by the protocol SAE J2601. After finding the Pareto frontier between filling time and total entropy production it was found that SAE J2601 is suboptimal in terms of these process variables. Specifically reductions of filling time from 47 to 77% are possible in the analyzed range of ambient temperatures (from 10 to 40 °C) with higher saving potential the hotter the weather conditions. Maximum entropy production savings with respect to SAE J2601 (7% for 10 °C 1% for 40 °C) demand a longer filling time that increases with ambient temperature (264% for 10 °C 350% for 40 °C). Considering average electricity prices in California USA the operating cost of the filling process can be reduced between 8 and 28% without increasing the expected filling time.

The road transport sector is one of the major contributors to greenhouse gas emissions as it still largely relies on traditional powertrain solutions. While some progress has been made in the passenger car sector with the diffusion of battery electric vehicles heavy-duty transport remains predominantly dependent on diesel internal combustion engines. This research aims to evaluate and compare three potential solutions for the decarbonisation of heavy-duty freight transport from an economic perspective: Battery Electric Trucks (BETs) Fuel Cell Electric Trucks (FCETs) and Hydrogen-fuelled Internal Combustion Engine Trucks (H2ICETs). The study focuses on the Finnish market and road network where affordable and low-carbon electricity creates an ideal environment for the development of alternative powertrain vehicles. The analysis employs the Total Cost of Ownership (TCO) method which allows for a comprehensive assessment of all cost components associated with the vehicles throughout their entire lifecycle encompassing both initial expenses and operational costs. Among the several factors affecting the results the impact of the three powertrain technologies on the admissible payloads has been taken into account. The study specifically focuses on the costs directly incurred by the truck owner. Additionally to evaluate the cost effectiveness of the proposed powertrain technologies under different scenarios a sensitivity analysis on electricity and hydrogen prices is conducted. The outcomes of this study reveal that no single powertrain solution emerges as universally optimal as the most cost-effective choice depends strongly on the truck type and its use (i.e. daily mileage). For relatively small trucks (18 t) covering short driving distances (approximately 100 to 200 km/day) BETs prove to be the best solution due to their higher efficiency and lower vehicle costs compared to FCETs. Conversely for larger trucks (42 and 76 t) engaged in longer hauls (>300 km/day) H2ICETs exhibit larger cost benefits due to their lower vehicle costs among the three options under investigation. Finally for small trucks (18 t) travelling long distances (200 km/day or more) FCETs represent a competitive choice due to their high efficiency and costeffective energy storage system. Considering future advancements in FCETs and BETs in terms of improved performance and reduced investment cost the fuel cell-based solution is expected to emerge as the best option across various combinations of truck sizes and daily mileages.

The present paper offers a thorough examination of the safety measures enforced at hydrogen filling stations emphasizing their crucial significance in the wider endeavor to advocate for hydrogen as a sustainable and reliable substitute for conventional fuels. The analysis reveals a wide range of crucial safety aspects in hydrogen refueling stations including regulated hydrogen dispensing leak detection accurate hydrogen flow measurement emergency shutdown systems fire-suppression mechanisms hydrogen distribution and pressure management and appropriate hydrogen storage and cooling for secure refueling operations. The paper therefore explores several aspects including the sophisticated architecture of hydrogen dispensers reliable leak-detection systems emergency shut-off mechanisms and the implementation of fire-suppression tactics. Furthermore it emphasizes that the safety and effectiveness of hydrogen filling stations are closely connected to the accuracy in the creation and upkeep of hydrogen dispensers. It highlights the need for materials and systems that can endure severe circumstances of elevated pressure and temperature while maintaining safety. The use of sophisticated leak-detection technology is crucial for rapidly detecting and reducing possible threats therefore improving the overall safety of these facilities. Moreover the research elucidates the complexities of emergency shut-off systems and fire-suppression tactics. These components are crucial not just for promptly managing hazards but also for maintaining the station’s structural soundness in unanticipated circumstances. In addition the study provides observations about recent technical progress in the industry. These advances effectively tackle current safety obstacles and provide the foundation for future breakthroughs in hydrogen fueling infrastructure. The integration of cutting-edge technology and materials together with the development of upgraded safety measures suggests a positive trajectory towards improved efficiency dependability and safety in hydrogen refueling stations.

Hydrogen energy as a zero-carbon emission type of energy is playing a significant role in the development of future electricity power systems. Coordinated operation of hydrogen and electricity will change the direction and shape of energy utilization in the power grid. To address the evolving power system and promote sustainable hydrogen energy development this paper initially examines hydrogen preparation and storage techniques summarizes current research and development challenges and introduces several key technologies for hydrogen energy application in power systems. These include hydrogen electrification technology hydrogen-based medium- and long-term energy storage and hydrogen auxiliary services. This paper also analyzes several typical modes of hydrogen–electricity coupling. Finally the future development direction of hydrogen energy in power systems is discussed focusing on key issues such as cost storage and optimization.

Fuel cell hybrid systems due to their combination of the high energy density of fuel cells and the rapid response capability of power batteries have become an important category of new energy vehicles. This paper discusses energy management strategies in hydrogen fuel cell vehicles. Firstly a detailed comparative analysis of existing PID control strategies and Adaptive Equivalent Consumption Minimization Strategies (A-ECMSs) is conducted. It was found that although A-ECMS can balance the energy utilization of the fuel cell and power battery well the power fluctuations of the fuel cell are significant leading to increased hydrogen consumption. Therefore this paper proposes an improved Adaptive Low-Pass Filter Equivalent Consumption Minimization Strategy (A-LPF-ECMS). By introducing low-pass filtering technology transient changes in fuel cell power are smoothed effectively reducing fuel consumption. Simulation results show that under the 6*FTP75 cycle the energy loss of A-LPF-ECMS is reduced by 10.89% (compared to the PID strategy) and the equivalent hydrogen consumption is reduced by 7.1%; under the 5*WLTC cycle energy loss is reduced by 5.58% and equivalent hydrogen consumption is reduced by 3.18%. The research results indicate that A-LPF-ECMS performs excellently in suppressing fuel cell power fluctuations under idling conditions significantly enhancing the operational efficiency of the fuel cell and showing high application value.

Modern energy conversion technologies with low or no emissions are needed to achieve sustainable development goals. This research examines the thermodynamic and exergy-economic features of a high-temperature proton exchange membrane fuel cell. A cutting-edge integrated energy system uses high-temperature proton exchange membrane fuel cells an organic Rankine cycle a proton exchange membrane electrolyzer and a multi-effect desalination unit. This setup generates electricity hydrogen and fresh water. Methanol-steam reformation produces hydrogen for the fuel cell. The recommended cycle drives an organic Rankine power producing cycle using 120-200 °C waste heat from hightemperature proton exchange membrane fuel cell to power water electrolysis and hydrogen generation. An integrated method incorporates energy and exergy balances and cost analysis to assess the proposed system's exergetic economic and environmental impacts. The suggested integration delivers high energy and exergy efficiency at an acceptable cost and environmental effect. According to parametric research boosting the fuel cell's working temperature decreases production costs and carbon dioxide emissions per mass. Raising current density has positive technical and environmental impacts. As the current density increases from 0.4 to 0.8 (A/cm2 ) the net power generation increases to 46.67% and the exergy efficiency increases from 64.5% to 68%. An increase in multi-effect distillation motivate steam pressure from 200 to 600 kPa results in an increase in the daily freshwater generated from 111.68 m3 to 116.41 m3 . For environmental protection and output optimization fuel utilization ratio must be reduced. The ideal system's exergy efficiency product unit cost and environmental impact are 65.78% 86.28 ($/h) and 4.33% respectively.

This paper proposes a systematic optimization framework to jointly determine the optimal location and sizing decisions of renewables and hydrogen storage in a power network to achieve the transition to low-carbon networks efficiently. We obtain these strategic decisions based on the multi-period alternating current optimal power flow (AC MOPF) problem that jointly analyzes power network renewable and hydrogen storage interactions at the operational level by considering the uncertainty of renewable output seasonality of electricity demand and electricity prices. We develop a tailored solution approach based on second-order cone programming within a Benders decomposition framework to provide globally optimal solutions. In a test case we show that the joint integration of renewable sources and hydrogen storage and consideration of the AC MOPF model significantly reduces the operational cost of the power network. In turn our findings can provide quantitative insights to decision-makers on how to integrate renewable sources and hydrogen storage under different settings of the hydrogen selling price renewable curtailment cost emission tax price and conversion efficiency.

This review focuses on the energy structure of iron and steel production and a feasible development path for carbon reduction. The process path and feasible development direction of carbon emission reduction in the iron and steel industry have been analyzed from the perspective of the carbon–electricity–hydrogen ternary relationship. Frontier technologies such as “hydrogen replacing carbon” are being developed worldwide. Combining the high efficiency of microwave electric-thermal conversion with the high efficiency and pollution-free advantages of hydrogen-reducing agents may drive future developments. In this review a process path for “microwave + hydrogen” synergistic metallurgy is proposed. The reduction of magnetite powder by H2 (CO) in a microwave field versus in a conventional field is compared. The driving effect of the microwave field is found to be significant and the synergistic reduction effect of microwaves with H2 is far greater than that of CO.

Global warming’s major cause is the emission of greenhouse-effect gases (GHG) especially carbon dioxide (CO2) whose main source is the combustion of fossil fuels. Fossil fuels serve as the primary energy source in many industries including shipping which is the focus of this study. One of the measures proposed to tackle GHG emissions is the development of green shipping corridors - carbon-free shipping routes that require the transition to alternative fuels which are gaining competitiveness. One of the reasons for that is carbon pricing which taxes CO2 emissions. However the lack of consensus on the most cost-advantageous alternative fuel in the long run results in the delay of the implementation of green shipping corridors. To make it more accessible for stakeholders to conduct an economic analysis of the various options a framework to determine and minimize the costs of transitioning from fossil fuels to any alternative fuel is proposed over the period of one voyage considering the lost opportunity cost the deployment cost of bunkering vessels at the necessary call ports the cost of converting the vessel the car-bon emissions tax cost and the fuel cost. This will allow stakeholders to choose the most economical alternative fuel accelerating the development of green shipping corridor initiatives. To validate the effectiveness of the framework it was applied in a case study involving a shipowner seeking to transition from heavy fuel oil (HFO) to Ammonia Hydrogen Liquefied Natural Gas (LNG) or Methanol. This study faced limitations due to the unknown costs of installing bunkering vessels for Ammonia and Hydrogen. However it evaluates the cost-effectiveness of alternative fuels providing insights into their short-term economic viability. The results showed that Hydrogen is the most costadvantageous fuel until a deployment cost per bunkering vessel of 1990285$ for a sailing speed of 22 knots and 2190171$ for a sailing speed of 18 knots is reached after which LNG becomes the most economical option regardless of variations in the carbon tax. Moreover a sensitivity analysis was conducted to determine the effects of variations in parameters such as carbon tax fuel prices and vessel conversion costs in the total cost of each fuel option. Results highlighted that even though HFO remains the most economical fuel option even when considering a high increase in carbon tax the cost gap between HFO and alternative fuels narrows significantly with the increase in carbon tax. Furthermore the sailing speed impacts the fuels’ competitiveness as the cost difference between HFO and alternative fuels decreases at higher speeds.