Hydrogen Energy Storage Research Articles

Techno-economic feasibility of integrating hybrid battery-hydrogen energy storage system into an academic building

Green hydrogen production and storage are vital in mitigating carbon emissions and sustainable transition. However, the high investment cost and management requirements are the bottleneck of utilizing hybrid hydrogen-based systems in microgrids. Given the necessity of cost-effective and optimal design of these systems, the present study examines techno-economic feasibility of integrating hybrid hydrogen-based systems into an outdoor test facility. With this perspective, several solar-driven hybrid scenarios are introduced at two energy storage levels, namely the battery and hydrogen energy storage systems, including the high-pressure gaseous hydrogen and metal hydride storage tanks. Dynamic simulations are carried out to address subtle interactions in components of the hybrid system by establishing a TRNSYS model coupled to a Fortran code simulating the metal hydride storage system. The OpenStudio-EnergyPlus plugin is used to simulate the building load, validate against experimental data, according to the measured data and monitored operating conditions. Aimed at enabling efficient integration of energy storage systems, a techno-enviro-economic optimization algorithm is developed to simultaneously minimize the levelized cost of the electricity and maximize the CO2 mitigation in each proposed hybrid scenario. The results indicate that integrating the gaseous hydrogen and metal hydride storages into the photovoltaic-alone scenario enhances 22.6% and 14.4% of the annual renewable factor. Accordingly, the inclusion of battery system to these hybrid scenarios gives a 30.4% and 20.3 % boost to the renewable factor value, respectively. Although the inclusion of battery energy storage into the hybrid systems increases the renewable factor, the results imply that it reduces the hydrogen production rate via electrolysis. The optimized values of the levelized cost of electricity and CO2 emission for different scenarios vary in the range of 0.376–0.789 $/kWh and 6.57–9.75 ton, respectively. The multi-criteria optimizations improve the levelized cost of electricity and CO2 emission by up to 46.2% and 11.3%, with respect to their preliminary design.

High-efficiency control strategies of a hydrogen turbo-expander for a 5 t/d hydrogen liquefier

Liquid hydrogen plays a crucial role in the large-scale storage and long-distance transportation of hydrogen energy. Effectively controlling hydrogen turbo-expanders is an important strategy for reducing energy consumption during liquefaction process. This study conducts both experimental and numerical investigations on a hydrogen turbo-expander within a 5 t/d hydrogen liquefaction system. A CFD model is developed to predict the performance of hydrogen turbo-expanders, which is then validated against experimental data. The numerical predictions of isotropic efficiency closely match experimental results, with a maximum deviation of 10 %. Throughout the cooling-down process, the efficiency of the hydrogen turbo-expander varies significantly, indicating a strong dependence on the characteristic ratio. Consequently, an optimal characteristic ratio method is proposed to maintain the hydrogen turbo-expander at peak efficiency. Compared to traditional control methods based on fixed brake pressure, the proposed approach achieves a maximum efficiency enhancement of 23.8 %. At the optimal characteristic ratio, the rotational speed can be maintained at the design level by adjusting brake pressure, which remains below the design value during the cooling-down phase. This investigation presents an effective method for optimizing the control of turbo-expanders in hydrogen liquefaction systems.

Optimizing the economic viability of proton exchange membrane fuel cells operated with oxygen-enriched cathode air for residential hydrogen energy storage systems

The recovery and utilization of oxygen in residential hydrogen energy storage systems significantly impact economic factors. This study introduces an algorithm tailored to optimize oxygen concentration (fraction) across varied operational conditions, encompassing considerations for both efficiency (positive aspect) and lifetime (negative aspect). Initially, an enhanced air supply system (ASS), functioning with oxygen-enriched cathode air, is devised following the forefront scheme. Moreover, a dynamic model is formulated based on MATLAB/Simulink® software for the proton exchange membrane fuel cell (PEMFC) system. The model enables quantitative assessment of system gains in relation to various current densities and oxygen fractions, and its accuracy is partially validated through experimental data. Further, a model correlating stack lifetime to oxygen concentration (fraction) is established using experimental data obtained from other researchers. Finally, the optimal oxygen fractions are determined and managed, with a comparison of the effects before and after optimization. The optimized results indicate a 13% improvement in stack net power at rated operating conditions and a 24% improvement at peak operating conditions, and the system efficiency is improved by 24% and 43% at rated and peak operating conditions, respectively. In addition, the minimum value of system efficiency is observed to be 54%, and there is a notable attenuation of the concentration polarization phenomenon. This approach contributes to mitigating the challenge of lower system efficiency in normal PEMFCs for residential hydrogen energy storage systems (RHESSs) attributed to inadequate gas supply pressure.

Study of the influence of different ignition times on detonation generation and shock wave propagation in high-pressure hydrogen leakage

Hydrogen is an efficient, clean, and renewable energy source. When determining a place for hydrogen energy storage and injection into vehicles, the main safety concern of hydrogen refueling stations is high-pressure hydrogen leakage. In this paper, the CFD method is used to study the effect of different ignition times on the explosion and shock wave propagation of high-pressure hydrogen gas leakage, analyze the distribution of flammable gas clouds, and evaluate the impact of combustion flames, temperature, and explosion-induced overpressure on refueling stations. The results show that the concentration of gas clouds ranges from 0 to 80% (volume concentration). Explosion and combustion phenomena occur at different ignition times during the high-pressure hydrogen gas leakage stage, with a maximum pressure of 2.6 bar and a high temperature of 1500–2400 K. After a high-pressure hydrogen leak, ignition can occur only as an explosive phenomenon. This generates a pressure of up to 3.1 bar and a short-lived high temperature. The pressure increases with the length of the leak, and the hazardous area varies depending on the time of ignition. This paper provides theoretical support for safety issues related to high-pressure hydrogen leakage in refueling stations.

Development pathway and influencing factors of hydrogen energy storage accommodating renewable energy growth

Hydrogen energy is considered an important energy storage mode with medium- and long-term cross-seasonal storage capabilities in scenarios with high penetration of renewable energy (RE). However, there is a lack of research regarding the appropriate scale of hydrogen energy storage (HES) considering different RE power generation scenarios. In response to this gap, the present study aims to establish a power system simulation model to analyze the development pathway of HES while accommodating RE growth with a minimum cost constraint for a power system operation. The impacts of carbon trading prices, advances in HES technology, and RE resource endowment on HES development are also investigated. The findings indicate that the total available solar energy resources in China are 46.94TW, and the total available wind energy resources are 9.52TW. When the share of RE generation reaches 44.33–54.78 % of total power generation, the utilization of HES for balancing power system is advantageous in reducing the overall system costs. Looking ahead to 2060, the year when China is projected to achieve its carbon-neutrality goal, RE is estimated to reach 63.12–91.1 % of total power generation. Consequently, the HES in each province is estimated to contribute to 3.58–18.02 % of total electricity consumption. Provinces with more abundant wind resources relative to solar resources are expected to have a 36.43 % higher demand for HES.

A comparative performance analysis of sensible thermal energy storage (with concentrated solar field and sCO2 Brayton Cycle) and hydrogen energy storage (with solar PV field)

Utility scale energy storage is an integral part of renewable energy installations to achieve sustainable and reliable transition to a net zero energy economy. There exists a myriad of such storage solutions each having unique characteristics. This paper attempts at a systems level quantitative study and comparison between two different energy storage technologies, Thermal Energy Storage System (TESS) which is already mature, and Hydrogen Energy Storage System (HESS) which gained a lot of momentum recently, with the former coupled with a concentrated parabolic trough solar field using molten salt as heat transfer fluid and a power block running on high efficiency sCO2 Brayton cycle while the latter is coupled with a solar photovoltaic (PV) field. So that comparisons can be made on similar scale, both the systems are normalized on the total equipment area used for capturing incident solar irradiation, i.e., total aperture area for the PTC field and total flat surface area of PV modules. Both the systems are subjected to year-long variations of ambient conditions and solar irradiance and off-design performances are simulated over various seasons. The results show superior performance of TESS in terms of roundtrip efficiency (96% as opposed to 32% with HESS) which also results in superior capacity utilization factor (CUF of 64.5% and 48% for TESS and HESS respectively) and better specific energy and energy density. However, HESS offers virtually infinite idling time where TESS has a shorter self-discharge time (17 h), and better power performance (specific power and power density) in 10MWe output range.

Using electrolytic hydrogen production and energy storage for balancing a low carbon electricity grid: Scenario assessments for India

Nuclear reactors and variable renewables will play a significant role in the global energy transition as providers of low carbon electricity to various end use sectors. Real time balancing of power demand and supply without modulation or curtailment is possible using electrolytic hydrogen plants and energy storage systems. The generation mix adopted and load profiles are unique to a country and this study considers the specific case of India. This work analyses the use of grid connected water electrolysers, grid scale battery storage, hydrogen storage and fuel cells as flexible loads and dispatch schemes for grid balancing. Based on postulated long term power generation scenarios for India, the minimum required system sizes for grid balancing are estimated and techno-economic uncertainties are assessed. The use of water electrolysers is prioritized to make use of excess power, while minimizing battery storage requirement. This scheme can potentially produce a substantial share of low carbon hydrogen in India for use in industrial decarbonization, thus reducing the need for additional generation infrastructure.

Energy Transformation Development Strategies: Evaluation of Asset Conversion in the Regions

Manifestations of energy transformation are visible throughout the developed world. As the threat to the survival of humanity arises, the countries of the world are starting to take faster and more specific actions to transform the energy sector. One of the energy transformation strategies is the decentralized development of the energy system in the regions. This concept is especially relevant at this time, when centralized sources of energy production and supply are becoming the target of physical and cyber attacks. The purpose of this article is to form theoretical assumptions for the smooth implementation of the decentralization of the energy system. This article aims to remove obstacles to short-term energy transformation. The novelty of this article is related to emphasizing the role of biomass cogeneration in achieving energy system efficiency and greening. Mathematical modeling based on RSM is used in the article. The established factors of the market structure revealed that the efficiency of energy production is based on the use of cogeneration and the markets for raw materials and energy can be attributed to different types. The results of this study showed that the optimal combination of biomass cogeneration can ensure competitive energy production. This article is relevant because it offers transitional solutions until adequate hydrogen utilization and energy storage solutions are developed.

Letter to the Editor on “Quantifying onshore salt deposits and their potential for hydrogen energy storage in Australia”

Letter to the Editor on “Quantifying onshore salt deposits and their potential for hydrogen energy storage in Australia”

Hierarchical online energy management for residential microgrids with Hybrid hydrogen–electricity Storage System

The increasing proportion of renewable energy introduces both long-term and short-term uncertainty to power systems, which restricts the implementation of energy management systems (EMSs) with high dependency on accurate prediction techniques. A hierarchical online EMS (HEMS) is proposed in this paper to economically operate the Hybrid hydrogen–electricity Storage System (HSS) in a residential microgrid (RMG). The HEMS dispatches an electrolyzer-fuel cell-based hydrogen energy storage (ES) unit for seasonal energy shifting and an on-site battery stack for daily energy allocation against the uncertainty from the renewable energy source (RES) and demand side. The online decision-making of the proposed HEMS is realized through two parallel fuzzy logic (FL)-based controllers which are decoupled by different operating frequencies. An original local energy estimation model (LEEM) is specifically designed for the decision process of FL controllers to comprehensively evaluate the system status and quantify the electricity price expectation for the HEMS. The proposed HEMS is independent of RES prediction or load forecasting, and gives the optimal operation for HSS in separated resolutions: the hydrogen ES unit is dispatched hourly and the battery is operated every minute. The performance of the proposed method is verified by numerical experiments fed by real-world datasets. The superiority of the HEMS in expense-saving manner is validated through comparison with PSO-based day-ahead optimization methods, fuzzy logic EMS, and rule-based online EMS.

Multi-functional hydrogen- and oxygen-capturing FeCo-N-C catalyst with improved hydrogenation of nitroarenes and ORR activity

Hydrogen energy storage and transportation are critical issues that must be addressed to ensure the development of alternatives to fossil fuel energy in the future. Herein, the poly(Schiff base) strategy is used to explore the carbon substrate, which is enclosed with binary metal Fe and Co as precursors. After the calcination and acid treatment steps, one of the FeCo alloy, termed FeCoNC-1000A900, was assembled with porous carbon skeleton as a shell and enclosed with FeCo alloy as a core. The FeCoNC-1000A900 exhibits outstanding H2 capture properties from NaBH4/EtOH mixtures circumstance owing to its large average particle size of 45 nm and high specific surface area of 462.07 m2/g. Notably, the FeCoNC-1000A900 acquires bi-functional catalysis efficacy, one is for chemoselectivity in the hydrogenation of nitroarene substrates and shows a high turnover frequency in 690 h−1 within the overall conversion yield. The other one is the O2 capture performance toward the oxygen reduction reaction with the excellent onset potential of 0.89 V, the half-wave potential of 0.77 V, and limiting current density of − 5.56 mA cm−2, which are comparable to those of the commercial Pt/C catalyst. In addition, the Tafel slope of 79.6 mV dec−1 is lower than those for other catalysts. Consequently, the development of the novel FeCoNC-1000A900 catalyst has two functional applications.

A Bi-level optimization for the planning of microgrid with the integration of hydrogen energy storage

Microgrid (MG) integrated with renewable energy sources (RES) has become increasingly popular, especially when the lack of resources and environmental pollution are serious. However, the uncertainty of RES is the major problem when operating MG. The hydrogen energy storage system (HESS) is a prominent solution for the RES uncertainty since it can store excess energy, supply when in shortage, help to regulate power consumption, and improve MG's flexibility. In this research, a bi-level optimization model for planning the microgrid is proposed. The upper layer of the optimization model aims to minimize the total operation cost of the MG, while the lower level focuses on minimizing the operation cost of the hydrogen energy storage system. The results demonstrate that the proposed bi-level model can help to reduce the operation cost of MG by 42.75% in comparison with typical single level optimization model. Additionally, the electricity generated by diesel generators has also decreased by 52.43%, resulting in a significant reduction in CO2 emissions and contributing to environmental protection.

Hydrogen energy storage integrated grid: A bibliometric analysis for sustainable energy production

Hydrogen energy storage and grid integration are emerging as key technologies for efficient energy generation and decarbonization, addressing the unpredictability of renewable sources like wind and solar. Hydrogen serves as a flexible energy carrier, enabling storage and conversion back to energy, and supporting various applications. Since there is a lack of bibliometric investigation in the grid-connected hydrogen energy storage system, this review conducted the bibliometric analysis and analyzed the role of hydrogen in enhancing grid-connected systems' sustainability and flexibility, based on data from the Scopus database. The principal search terms that have been used to identify the publications are “Hydrogen AND Storage AND ("Grid-connected" OR "On-grid" OR “Grid-tied” OR “Integrated grid” OR “Grid integration”)” and several keywords have also been utilized in the filter including “Hydrogen Storage”, “Hydrogen”, “Hydrogen Production” and “Grid-connected”. The chosen documents type is only comprised of ‘Article’ and ‘Review’. By conducting an analysis of publication trends, citation patterns, co-authorship, and keyword usage, significant and informative observations regarding the development of grid-connected hydrogen storage system research from 2013 to 2023 (up until November) were unveiled. Notably, 86.55% of the articles focused on simulation study, while the rest are focusing in experimental work, reviews, and technical overview of integrated-grid hydrogen storage system. China is establishing itself as prominent participant, while International Journal of Hydrogen Energy is recognized as a notable medium for distributing research on the integrated-grid hydrogen storage system. Compressed hydrogen tank emerges as a prominent type of storage because of its less energy requirement to increase the density of hydrogen that allow more efficient transportation for hydrogen. The review also underlines numerous factors, issues, challenges, and difficulties that next-generation hydrogen energy storage production should overcome with regards to system sustainability.

Synergistic interactions of electronic modulation and low crystallization in Ru-RuO2/C heterostructure for highly efficient multifunctional electrocatalysis

Developing electrocatalysts with multifunctional performance is crucial for hydrogen energy storage and conversion, but still a great challenge. Herein, an efficient trifunctional electrocatalyst with heterostructure is fabricated by a sequential reduction and annealing approach. With different annealing atmospheres, Ru-RuO2/C electrocatalysts having different Ru/RuO2 atomic ratios or different crystallinities were achieved. Among these electrocatalysts, Ru-RuO2/C annealed from N2-air mixed atmosphere (Ru-RuO2/C 250NA) displays the most excellent performance, affording overpotential values of 30.63 mV for alkaline hydrogen evolution reaction (HER) and 273.42 mV for alkaline oxygen evolution reaction (OER) at 10 mA cm−2, much lower than those of state-of-the-art Pt/C (η10, HER = 46.57 mV) and RuO2 (η10, OER = 288.99 mV). Not only that, it also delivers favorable activity for alkaline hydrogen oxidation reaction (HOR), with 2.1 times of mass specific exchange current density than that of Pt/C. The experimental and theoretical investigations prove the electron rearrangement at Ru and RuO2 interface with abundant defects and amorphous/crystalline structures. The synergistic effect of dual active sites simultaneously optimizes H and OH as well as H2O adsorption energies, endowing the Ru-RuO2/C 250NA as the preferential electrocatalysts.

Bi-level configuration and operation collaborative optimization of shared hydrogen energy storage system for a wind farm cluster

Energy storage is indispensable to achieve dispatchable and reliable power generation through renewable sources. As a kind of long-duration energy storage, hydrogen energy storage systems are expected to play a key role in supporting the net zero energy transition. However, the high cost has become an obstacle to hydrogen energy storage systems. The shared hydrogen energy storage (SHES) for multiple renewable energy power plants is an emerging mode to mitigate costs. This study presents a bi-level configuration and operation collaborative optimization model of a SHES, which applies to a wind farm cluster. Different operation modes, including the ‘electricity‑hydrogen-electricity (E-H-E)’ mode and the ‘electricity‑hydrogen (E-H)’ mode, are considered. Results show that SHES system offers substantial advantages over individual hydrogen energy storage solutions. It achieves a notable reduction in annual operation and maintenance (O&M) costs by 9.5 % and a significant increase in annual profit by 10.49 %. Moreover, the SHES system demonstrates a lower wind curtailment rate of 0.24 %, in contrast to the 0.37 % observed in individual cases. SHES will play a more significant role in larger wind farm clusters. The aforementioned advantages of SHES systems become even more pronounced in larger wind farm clusters, where their impact on cost reduction and efficiency is significantly amplified.

Multi-Objective Robust Optimization of Integrated Energy System with Hydrogen Energy Storage

A novel multi-objective robust optimization model of an integrated energy system with hydrogen storage (HIES) considering source–load uncertainty is proposed to promote the low-carbon economy operation of the integrated energy system of a park. Firstly, the lowest total system cost and carbon emissions are selected as the multi-objective optimization functions. The Pareto front solution set of the objective function is applied by compromise planning, and the optimal solution among them is obtained by the maximum–minimum fuzzy method. Furthermore, the robust optimization (RO) approach is introduced to cope with the source–load uncertainty effectively. Finally, it is demonstrated that the illustrated HIES can significantly reduce the total system cost, carbon emissions, and abandoned wind and solar power. Meanwhile, the effectiveness of the proposed model and solution method is verified by analyzing the influence of multi-objective solutions and a robust coefficient on the Chongli Demonstration Project in Hebei Province.

Energy Transition in Vietnam: A Strategic Analysis and Forecast

Energy landscapes in Asia and other regions are currently undergoing a transformation aimed at increasing the share of clean energy sources. This article analyzes and forecasts the electricity demand in Vietnam, examining existing constraints that necessitate the shift from coal to renewable energy sources. The rapid economic growth in Vietnam is driving a substantial surge in electricity demand, projected to reach 124 thousand MW by 2030 according to the National Electricity Plan, positioning Vietnam second in Southeast Asia. This surge poses a significant challenge to national energy security, given the impracticality of effective coal mining in the country and the imperative to develop renewable energy sources. Anticipating the changes in Vietnam’s energy mix by 2050, this study foresees a substantial reduction in dependence on coal production. Government investment and green energy investment funds such as JETP are strategically directed towards renewable energy sources, including solar, wind, biomass, hydrogen energy, and efficient energy storage technologies. Consequently, this research substantiates the viability of an energy transition from coal to green energy in Vietnam. The article presents an assessment of the rate of replacing coal with renewable energy sources, taking into consideration various scenarios for economic development, energy consumption growth, and the utilization of renewable energy sources.

A method based on machine learning to help determine the availability of hydrogen energy storage system in hydropower stations

A method based on machine learning to help determine the availability of hydrogen energy storage system in hydropower stations

Development and assessment of a novel isobaric compressed hydrogen energy storage system integrated with pumped hydro storage and high-pressure proton exchange membrane water electrolyzer

In the work, a novel isobaric compressed hydrogen energy storage system integrated with pumped hydro storage and high-pressure proton exchange membrane water electrolyzer is proposed to improve system performance. By integrating pumped hydro storage, the gas storage chamber can operate with a constant pressure at a counter-hydraulic pressure, enhancing the effectiveness and energy storage density of the system. Utilizing high-pressure proton exchange membrane water electrolyzer technology directly to produce high pressure hydrogen and oxygen simplifies the system structure by eliminating the need for gas compressors and cooling unit, thereby improving system stability. Additionally, insulated storage reservoirs are employed in the proposed system to store working fluids, maximizing system performance by minimizing potential waste heat losses. Furthermore, the electrical, thermal, and exergy efficiencies, as well as energy storage density of the proposed system, are assessed using thermodynamic techniques. The results indicate that the round-trip electrical efficiency, round-trip thermal efficiency, round-trip exergy efficiency, and energy storage density of the system can reach 35.39%, 81.03%, 37.89% and 53.46 kWh/m3, respectively. Lastly, parametric studies are conducted to further evaluate system performance under various working conditions.

First-principles study on a Li-decorated two-dimensional g-C6N6 monolayer: A promising ambient temperature reversible H2 storage material

Designing novel materials that exhibit superior reversibility and function under ambient conditions can facilitate the development of hydrogen energy applications. Two-dimensional (2D) g-C6N6 monolayers show great potential for use in hydrogen storage owing to their nanoporous structure, ultralight mass, and flexible electronic structure. However, the hydrogen storage potential of these materials is limited by the naturally weak interaction between 2D materials and hydrogen molecules caused by van de Waals forces. To address this issue, we studied the hydrogen storage performance of the complex by decorating active Li ions on a 2D g-C6N6 substrate through first-principles calculations. Our results showed that modifying the Li ions did not cause the original planar structure to deform but rather induced more active sites for hydrogen adsorption by establishing an electrostatic field between the Li ions and the g-C6N6 monolayer. Through this modification, reversible hydrogen storage was achieved under ambient conditions with an average adsorption energy of −0.197 eV/H2 and a high gravimetric capacity of 5.88 wt%. The electronic properties of the material were systematically investigated, and the results suggested that the enhanced capacity of the Li@ g-C6N6 system to store hydrogen resulted from the formation of a polarization field and the induced electrostatic effect. Our research offers a new possibility for achieving reversible hydrogen energy storage at room temperature.