Future Energy Systems Research Articles

The costs of hydrogen and conventional energy carriers: temporal evolutions and mutual price correlations – global insights with a focus on Belgium

ABSTRACT Energy systems design is challenged by uncertainties in energy carrier costs. This study explores hydrogen and conventional energy carrier costs, providing global insights with a focus on Belgium. Over two years, European natural gas prices surged 55-fold, while solid biomass prices varied only 1.8-fold over 13 years. Regression analysis (adjusted R 2 >0.9) reveals mutual correlations among energy carriers, allowing for cost ranking relative to the natural gas price. The relationship between electricity and natural gas prices underscores financial challenges for heat pumps in Belgium. Hydrogen cost estimations for 2024 are 43.7, 48.8, 16.4, and 17.5 €/GJH2,LHV for green, yellow (grid), grey and blue hydrogen, respectively. Achieving cost parity between blue and grey hydrogen requires a carbon tax of 67.5–123 €/tonCO2. Present approach incorporates uncertainties in energy carrier costs by varying natural gas price scenarios, facilitating prompt identification of cases for in-depth evaluation in future energy systems.

The effects of fair allocation principles on energy system model designs

Abstract What constitutes socially just or unjust energy systems or transitions can be derived from the philosophy and theories of justice. Assessments of distributive justice and utilising them in modelling lead to great differences based on which justice principles are applied. From the limited research so far published in the intersection between energy systems modelling and justice, we find that comparisons between the two principles of utilitarianism and egalitarianism dominate in assessments of distributive justice, with the latter most often considered representing a 'just energy system'. The lack of recognition of alternative and equally valid principles of justice, resting on e.g. capabilities, responsibilities and/or opportunities, leads to a narrow understanding of justice that fails to align with the views of different individuals, stakeholders and societies. More importantly, it can lead to the unjust design of future energy systems and energy systems analysis. 
 
In this work, we contribute to the growing amount of research on distributive justice in energy systems modelling by assessing the implications of different philosophical views on justice on modelling results. Through a modelling exercise with a power system model for Europe (highRES), we explore different designs of a future (2050) net-zero European electricity system, and its distributional implications based on the application of different justice principles. In addition to the utilitarian and egalitarian approach, we include, among others, principles of 'polluters pay' and 'ability-to-pay', which take historical contributions of greenhouse gas emissions and the socio-economic conditions of a region into account. 
 
We find that fair distributions of electricity generating infrastructure look significantly different depending on the justice principles applied. The results may stimulate a greater discussion among researchers and policymakers on the implications of different constructions of justice in modelling, expansion of approaches, and demonstrate the importance of transparency and assumptions when communicating such results.

Assessment of a coupled electricity and hydrogen sector in the Texas energy system in 2050

Due to its ability to reduce emissions in the hard-to-abate sectors, hydrogen is expected to play a significant role in future energy systems. This study modifies a sector-coupled dynamic modeling framework for electricity and hydrogen by including policy constraints, carbon prices, and possible hydrogen pathways and applies it to Texas in 2050. The impact of financial policies, including the US clean hydrogen production tax credit, on required infrastructure and costs are explored. Due to low natural gas prices, financial levers are necessary to promote low-carbon hydrogen production as the optimized solution. The Levelized Costs of Hydrogen are found to be $1.50/kg in the base case (primarily via steam methane reformation production) and lie between $2.10 - 3.10/kg when production is via renewable electrolysis. The supporting infrastructure required to supply those volumes of renewable hydrogen is immense. The hydrogen tax credit was found to be enough to drive production via electrolysis.

Dynamic Modeling of a HeXe-Cooled Mobile Nuclear Reactor with Closed Brayton Cycle

Helium-xenon (HeXe)-cooled mobile nuclear reactors have promising potential in future low-carbon energy systems. However, there is currently a lack of fast and reliable tools for analyzing the complicated dynamic characteristics of such systems. In this study, we developed a comprehensive dynamic modeling approach for a HeXe-cooled nuclear power system coupled with a closed Brayton cycle (CBC). The system’s key components, including the reactor, printed circuit heat exchanger (PCHE), and turbomachinery, are lumped-modeled to capture their time-varying behavior. A step-solving algorithm that incorporates HeXe mass conservation iteration is designed. The verification results demonstrate that the dynamic program is robust and reliable, with each time step converging within 25 iterations and the HeXe mass remaining within the range of 3.755 ± 0.01 kg throughout the simulation meeting the law of mass conservation. Then, a 1500 s frozen start-up simulation for the coupled system is conducted, in which the CBC is started in the first 500 s by increasing the main shaft speed to 40% of the rated value, and then the reactor is started by inserting external reactivity between 500 and 800 s. Both the dynamic process and the steady-state performance after the start-up are analyzed. The results show that the system achieved a stable electrical output of 5.7 MWe with a thermal efficiency of 32.5%. This study lays a solid foundation for future work aimed at improving the overall efficiency and performance of HeXe-cooled nuclear power systems.

Tackling the multitude of uncertainties in energy systems analysis by model coupling and high-performance computing

This paper identifies and addresses three key challenges in energy systems analysis—varying assumptions, computational limitations, and coverage of a few indicators only. First, results depend strongly on assumptions, i.e., varying input data. Hence, comparisons and robust results are hard to achieve. To address this, we use a broad range of possible inputs through an extensive literature review by scenario experts. Second, we overcome computational limitations using high-performance computing (HPC) and an automated workflow. Third, by coupling models and developing 13 indicators to evaluate the overall quality of energy systems in Germany for 2030, we include many aspects of security of supply, market impact, life cycle analysis and cost optimization. A cluster analysis of scenarios by indicators reveals three recognizable clusters, separating systems with a high share of renewables clearly from more conventional sets. Additionally, scenarios can be identified which perform very positive for many of the 13 indicators. We conclude that an automated, coupled workflow on supercomputers based on a broad parameter space is able to produce robust results for many important aspects of future energy systems. Since all models and software components are released as open-source, all components of a multi-perspective model-chain are now available to the energy system modeling community.

City energy planning: Modeling long-term strategies under system uncertainties

Cities are facing the dilemma of fulfilling energy service demands for their rapidly growing population while also working towards climate mitigation efforts. City energy planning is essential to deal with this dilemma. Thus, this study explores the role of city energy plans on future cost-efficient energy systems. A technology-rich cost-optimization model was developed using TIMES with intra-sectoral and inter-sectoral interactions and applied to the Gothenburg energy system. The model outcomes are investigated with the application of policy-driven scenarios and further tested under system uncertainties and price sensitivities identified using a participatory approach. Heating sector developments include DH production based on biomass CHP and heat pumps combined with improved building energy efficiency. Cost-efficient transport sector developments show a rapid deployment of biofuel vehicles, followed by increasing electrification later in the time horizon. With the applied uncertainties, different cost-optimal district heat production mixes and heating supply solutions are observed, providing alternative planning strategies. The model results also signify competition of biomass and electricity among sectors in their development pathways. The modeling outcomes enable decision-makers to assess various energy systems transition strategies from a long-term perspective.

Hydrogen Storage Materials: Promising Materials for Kazakhstan’s Hydrogen Storage Industry

Hydrogen, widely recognized as an efficient and clean energy carrier, holds significant promise for transforming future energy systems. Despite advances in hydrogen production and cost reduction, challenges in hydrogen storage continue to impede its widespread adoption. Traditional storage methods, such as high-pressure tanks and liquid hydrogen, have limitations related to high energy and resource costs. Solid-state materials offer a safer and more reliable alternative for hydrogen storage under various operating conditions. This review article provides an in-depth analysis of hydrogen storage materials, focusing on metal hydrides, complex hydrides, and carbon-based materials, with particular attention to their thermodynamic, structural, and kinetic properties. Additionally, the article explores the potential application of certain materials in Kazakhstan's hydrogen market, highlighting the country's rich mineral resources and existing industrial infrastructure. By leveraging these resources, Kazakhstan can play a crucial role in advancing hydrogen storage technologies and contributing to global decarbonization efforts. The review aims to offer comprehensive insights into the current state and prospects of solid-state hydrogen storage materials, emphasizing their relevance and potential impact on Kazakhstan's energy sector.

Systemic Innovation in the European Energy Sector: A Collective Outlook

Applying the principles of systems thinking in the evolution of energy systems is a crucial approach to meet the long-term horizons of goals in the energy sector. Through a participatory approach, this paper outlines what we view as the trends shaping the current development of the energy sector; the challenges we must face as a result, and the transitions required to tackle them. Furthermore, we discuss how systems thinking can address these challenges through changing not the components, but rather their relationships and structures. Contributing to the emerging stream of literature applying more holistic approaches to energy transitions, in contrast to more linear systems modelling. We provide innovative insights into how future energy systems could be designed to become more regenerative, resilient, empowering, whilst technologically- and economically feasible; to overcome the challenges of carbon lock-in effects and carbon capture, the rebound effects of efficiency strategies, and social sustainability for just transitions.

Socio economic perspectives on fusion power for a sustainable future energy system

In the global effort towards the mitigation of climate change, low-carbon electricity generating technologies play a pivotal role. Nuclear fusion stands as a highly promising option for carbon-free electricity generation in a sustainable, reliable, affordable and socially acceptable future energy system. The EUROfusion work package “Socio Economic Studies” (WPSES) on fusion conducts research aimed at identifying social and economic conditions that can effectively support fusion deployment in future energy markets. Placing nuclear fusion in the broader context of energy and climate issues, the SES research explores fusion as an energy technology contributing to sustainable energy production for the future society. Because of the cross-cutting nature of the research, SES studies can provide decision-makers with scientific evidence relevant for shaping appropriate strategies in favour of fusion. This paper aims to offer the scientific community a thorough overview of EUROfusion SES research, addressing a gap in the current literature.

System friendliness of distributed resources in sustainable energy systems

The increasing share of volatile renewable energy generation in current and future energy systems which does not follow the demand, makes it necessary to shift the synchronization tasks to the system and demand level. The intended demand side consumption management is usually incentivized via financial mechanisms. However, the optimum design of related incentives is still unclear. It is usually discussed under the term “system friendliness” which in turn still lacks a broadly accepted definition. In this article we introduce a new technical definition of “system friendliness” and develop comprehensive and holistic related indicators. For that, we introduce the burden concept for energy systems which represents the amount of technical infrastructure required for stable operation. We use the concept of a hypothetical system energy storage to derive indicators that are capable of quantifying the system friendliness of a given point-of-interest. The developed indicators are independent of regulations or market environments which enables comparability of results between studies and different systems. In a case study we demonstrate our newly developed methodology and exemplary examine decentral district energy storages. Our findings demonstrate that today’s regulatory environments that usually support residential self-consumption maximization are counterproductive. Instead, we show that dynamic end-user prices coupled with dynamic feed in tariffs are able to incentivize an almost 100% system friendly behavior of distributed prosumers.

Regional CCUS strategies in the context of a fully decarbonized society

Global strategies to combat climate change must be implemented through actions at the local level. The complexity and interconnection of the global challenges are, however, difficult to interpret at the local level. This requires enhanced collaboration and coordination together with a shared understanding of the interconnected nature of our energy systems and the strategies that shape them. Global, international, and national strategies for carbon capture utilization and storage (CCUS) have emerged in recent years as carbon is increasingly outlined as a key element in the future energy system. This emphasizes CCUS strategies as an important part of a transition toward a fully decarbonized society. Therefore, principal strategies for CCUS and the energy system need to be coordinated and translated following a spatiotemporal assessment to enable meaningful actions at the local level. This article applies a regional perspective, in which a regional energy system model seeks to bridge the gap between national and local energy planning. The regional energy system is developed as part of an overarching national scenario for the transition towards a fully decarbonized society. This context provides a national boundary shaped by a global ceiling to provide a meaningful and adequate framework for regional and local development in the future. The overarching national scenario frames the potentials and constraints of the regional energy system and CCUS strategies as part of a global transition while enabling investigations of potential ramifications from changes in national objectives. The analysis in the article uses the North Denmark Region as a case and investigates scenarios in which the region assumes various roles as a contributor to the national transition. The results indicate a need for more interactive and dynamic energy planning and CCUS strategies to comprehend possible impacts from the various roles and changes in the national objectives. This article suggests that spatial and temporal awareness at the regional level of CCUS strategies as part of a future fully decarbonized society is key to creating a meaningful context for local actions today.

Electrolyte-supported solid oxide electrochemical cells for versatile operations

Electrolyte-supported solid oxide electrochemical cells (SOCs) offer advantages in terms of easier fabrication and enhanced mechanical properties, but achieving high performance and multifunctionality remains challenging. In this study, we develop high-performance and versatile electrolyte-supported SOCs using La0.9Sr0.1Ga0.8Mg0.2O3-δ (LSGM) electrolyte materials through microstructural engineering of Sr2Fe1.5Mo0.5O6-δ (SFM)-based fuel electrodes. We evaluate the cells for power generation, hydrogen production, and carbon dioxide reduction, showcasing the diverse potential of various fuel electrode configurations. Among these, the impregnated SFM@LSGM electrode achieves the best overall performance, with a maximum power density of 739 mW cm−2 in fuel-cell mode, a current density of −0.81 A cm−2 at 1.3 V during steam electrolysis, and an unprecedented current density of −1.92 A cm−2 at 1.5 V in CO₂ electrolysis. Furthermore, it exhibits satisfactory stability across all operational modes. These findings provide valuable insights into the design of versatile electrolyte-supported SOCs and open new possibilities for their flexible applications in future low-carbon energy systems.

Optimal rule-based energy management and sizing of a grid-connected renewable energy microgrid with hybrid storage using Levy Flight Algorithm

The study addresses the integration of hybrid hydrogen (H2) and battery (BT) energy storage systems into a renewable energy microgrid comprising solar photovoltaic (PV) and wind turbine (WT) systems. The research problem focuses on improving the effectiveness and computational efficiency of energy management systems (EMS) while ensuring high system reliability. Despite the existing optimization methods for hybrid microgrids, challenges remain in optimizing energy storage and capacity planning in grid-connected microgrids. To solve this, we propose the use of the Levy Flight Algorithm (LFA) to optimize the capacities of PV, WT, H2 tanks, electrolyzers (EL), fuel cells (FC), and BT, which presents a complex nonlinear optimization challenge. The novelty of this study lies in integrating the LFA with a rule-based EMS, enhancing system reliability and efficiency. The proposed approach significantly reduces the annualized system cost (ASC) and the levelized cost of energy (LCOE). The result demonstrate that the LFA outperforms methods like the Salp Swarm Algorithm (SSA), Particle Swarm Optimization (PSO), Grey Wolf Optimization (GWO) and Genetic Algorithm (GA), yielding cost savings of $3,309, $5,297, $4,484, and $5,129 respectively. The LFA achieves the lowest LCOE at $0.275/kWh, compared to $0.278/kWh with SSA, $0.289/kWh with GA, $0.280/kWh with PSO and $0.283/kWh with GWO. This research contributes to the broader scientific community by providing a more efficient approach to optimizing renewable energy microgrids with hybrid storage systems, thus promoting eco-friendly and cost-effective energy solutions. The proposed system design offers a pathway to future energy systems with high renewable integration, especially as technology advances and costs continue to decrease.

HeatNetSim: An open-source simulation tool for heating and cooling networks suitable for future energy systems

HeatNetSim: An open-source simulation tool for heating and cooling networks suitable for future energy systems

Impacts of lifestyle changes on energy demand and greenhouse gas emissions in Germany

Most energy scenario studies typically focus on technological options and fuel substitution for decarbonising future energy systems. Lifestyle changes are rarely considered, although they can significantly reduce energy demand and climate change mitigation efforts. By using an energy system model, this study shows that it is possible to reduce final energy demand in Germany by 61 % in 2050 relative to 2019 levels, resulting in an annual per capita energy demand of 44 GJ for a representative country of the Global North. This goal can be achieved through a combination of technological measures and lifestyle changes without sacrificing a decent standard of living. Societal chances can eliminate reliance on not-yet-established negative emission technologies, reduce energy dependency, and reduce the need for energy-intensive hydrogen and e-fuels. Downsizing the energy system provides an opportunity for strengthening climate change mitigation, decrease material demand and reduce land use.

In situ Construction of Single‐Atom Electronic Bridge on COF to Enhance Photocatalytic H2 Production

AbstractPhotocatalytic hydrogen production is one of the most valuable technologies in the future energy system. Here, we designed a metal‐covalent organic frameworks (MCOFs) with both small‐sized metal clusters and nitrogen‐rich ligands, named COF‐Cu3TG. Based on our design, small‐sized metal clusters were selected to increase the density of active sites and shorten the distance of electron transport to active sites. While another building block containing nitrogen‐rich organic ligands acted as a node that could in situ anchor metal atoms during photocatalysis and form interlayer single‐atom electron bridges (SAEB) to accelerate electron transport. Together, they promoted photocatalytic performance. This represented the further utilization of Ru atoms and was an additional application of the photosensitizer. N2‐Ru‐N2 electron bridge (Ru‐SAEB) was created in situ between the layers, resulting in a considerable enhancement in the hydrogen production rate of the photocatalyst to 10.47 mmol g−1 h−1. Through theoretical calculation and EXAFS, the existence position and action mechanism of Ru‐SAEB were reasonably inferred, further confirming the rationality of the Ru‐SAEB configuration. A sufficiently proximity between the small‐sized Cu3 cluster and the Ru‐SAEB was found to expedite electron transfer. This work demonstrated the synergistic impact of small molecular clusters with Ru‐SAEB for efficient photocatalytic hydrogen production.

Facile synthesis of spherical-shaped CeC2–TiO2 nanocomposite electrocatalyst with boosted alkaline OER

Developing noble metal-free multifunctional electrocatalysts to catalyze water oxidation is vital for future renewable energy systems. Herein, through several defect modifications, the CeC2–TiO2 nanocomposite on the strength of enriched oxygen vacancies was successfully fabricated by facile hydrothermal method on SS (stainless steel) substrate, attributed to the conductive ability for fast electron transportation. A well-defined phase growth, vibrational bonding of metal atoms, morphological determination, and elemental composition for synthesized heterostructured electrocatalysts were revealed by XRD, FTIR, TEM, and EDX, respectively. XPS has complied to understand the moderate binding energies of CeC2–TiO2 for OER intermediates, which signifies the strong interactions between electronic states of Ce, C, Ti, and O atoms. With the plentiful catalytic active sites, the resultant CeC2–TiO2 entails low overpotentials of only 169 mV and 108.8 mV/dec Tafel slope to afford 10 mA cm−2 for OER in 1.0 M KOH are tested through cyclic and linear sweep voltammogram measurements, thereby exhibit promising activity in alkaline water electrolysis. EIS measurements revealed a decreased polarization resistance for the composite dominated by the small semicircle diameter, corresponding to the adsorption of intermediates. Finally, observed results strongly recommended that the CeC2–TiO2 catalyst exhibited superior OER performance due to excellent electrical chemical coupling between CeC2 and TiO2.

Grid-integrated solutions for sustainable EV charging: a comparative study of renewable energy and battery storage systems

IntroductionThe integration of electric vehicles (EVs) into the power network challenges the 1) grid capacity, 2) stability, and 3) management. This is due to the 1) increased peak demand, 2) infrastructure strain, and 3) intermittent charging patterns. Previous studies lack comprehensive integration of renewable energy and battery storage with EV charging.MethodsTo address these challenges, this study explores the effectiveness of incorporating renewable energy resources (RERs) and battery energy storage systems (BESS) alongside the traditional grid. The proposed study utilizes the HOMER Grid® and conducted a comprehensive analysis.ResultsThe proposed study compares two grid integrated scenarios: 1) Case-1 (grid and photovoltaic (PV) systems), and 2) Case-2 (grid, PV systems, and BESS). Both these scenarios are compared against a Base case relying solely on grid power. The evaluation employed techno-economic analysis while focusing on 1) net present cost (NPC), 2) cost of energy, and 3) annualized savings. Additionally, the proposed study analyzed 4) seasonal variations in EV charging demand, 5) grid interactions, 6) PV production, and 7) the operation of BESS in both summer and winter. The comparative analysis reveals that the Base case incurs a net present cost (NPC) of $546,977 and a cost of energy (COE) of $0.354 per kWh. In contrast, Case-1, which integrates a 100 kW PV system, shows a significantly lower NPC of -$122,962 and a reduced COE of -$0.043 per kWh, with annualized savings of $61,492. Case-2, incorporating both the 100 kW PV system and a BESS with a capacity of 9.8 kWh, has a higher NPC of $309,667 but a COE of $0.112 per kWh and provides annual savings of $51,233 compared to the Base case.DiscussionSeasonal analysis highlights that Case-2 achieves the lowest carbon emissions in summer, ranging from 2.0 to 2.5 tons, while Case-1 shows the lowest emissions in winter, ranging from 3.2 to 3.4 tons. This model 1) reduces operational costs, 2) minimizes carbon emissions, while 3) making it compelling for future energy systems in increasing EV adoption.

Flame dynamic insights into pollutant production characteristics of NH[formula omitted]/H[formula omitted]/air combustion during turbulent flame–wall interaction

A turbulent premixed NH3/H2/air flame with Damköhler number Da = 0.004 has been simulated using direct numerical simulations (DNS) with detailed chemistry. The flame is propagating in a fully-developed turbulent channel flow with friction Reynolds number Reτ = 313. The global and local production speeds of NO, N2O and NH3 have been analyzed. Special attention is paid on the flame dynamic insights into the pollutant production characteristics during the flame–wall, flame–turbulence and flame–flame interaction process. Finally, important findings have been concluded: (1) The unburned NH3 is reduced in the turbulent case due to the smaller quenching distance; (2) The N2O consumption speed would decrease just before flame quenching on the wall in the turbulent case, due to the thickened flame thickness, which is contradictory to the laminar case; (3) Effect of flame curvature on pollutant production speeds should be combined with the effect of flame surface density; (4) Low Damköhler number flame tends to produce more N2O and less NO, due to the more frequent flame–flame interaction events. These findings would help to better understand the pollutant production characteristics of turbulent premixed NH3/H2/air flames in lab-scale burners with strong flame–wall interactions.Novelty and Significance StatementThe novelty of this research is summarized into 3 points: (1) It is, to our knowledge the first time, pollutant production characteristics are investigated in detail for the premixed NH3/H2/air flame propagating in a fully developed turbulent boundary layer; (2) The effects of flame–wall, flame–turbulence and flame–flame interactions, the underlying reasons and controlling mechanisms are investigated in detail, which has not yet been (comprehensively) done in previous studies; (3) Novel and important findings have been concluded for the wall effects, turbulence effects (including flame curvature and surface density function effects) and flame–flame interaction effects. Some of these findings have never been reported before, but important for the comprehensive understanding of the pollutant production characteristics. It is significant because understanding the turbulence and wall effects on NO, N2O and NH3 production characteristics in the premixed NH3/H2/air flames is crucial for the future clean combustion energy system design.

Environmental Awareness and Social Sustainability: Insights from an Agent-Based Model with Social Learning and Individual Heterogeneity

Social sustainability requires both technological innovations and societal changes within energy systems, with decentralization playing a critical role. This shift emphasizes the increasing importance of individual user decision-making, posing significant management challenges. An individual’s environmental awareness has a key influence on their energy decisions. However, the relationship between individual environmental awareness and social sustainability, particularly from a systemic perspective, remains underexplored. Our study uses agent-based modeling to examine this relationship within Japan’s electricity market, focusing on social learning and consumer heterogeneity. We find that social learning leads to the formation of consumer clusters with specific electricity preferences, affecting environmental awareness differently across high- and low-carbon groups. This process reveals the nuanced role of social learning in promoting low-carbon technology adoption, which varies according to the market share of low-carbon energy. Additionally, our results suggest that initial heterogeneity in environmental awareness among consumers has a limited and varied effect on sustainable transition pathways. However, the diversity resulting from social learning significantly shapes these trajectories. These insights highlight the complex interplay between individual behaviors, societal dynamics, and technological advancements in steering the sustainable transition, providing valuable considerations for future energy system management.