Publications

Concerns about the competitiveness of European industry led to the publication of the Draghi report. One of his recommendations is to install regional green industrial clusters around energy-intensive companies. The report identifies three benefit categories each corresponding to typical industrial symbiosis cases: improved investment cases by shared local low-carbon energy generation improved investment cases by shared infrastructure and improved energy flows for increased resource efficiency. Industrial clusters hold untapped potential to advance the energy transition and climate neutrality. However it is still unknown how and if this potential will ever be reached nor how scalable and replicable the benefits will be. This review paper aims to take a first step in exploring the potential role of industrial clusters in the energy system by exposing the research state of the art in academic literature. A literature review is performed in line with the three benefit categories according to Draghi to understand the enablers and barriers of potential synergies and their impact on the energy system. Afterwards the scalability is assessed by positioning the European industrial clusters in the larger renewable energy landscape. To illustrate the global interest a brief reflection is made on references to industrial clusters in the policy of non-European regions. The work concludes with interesting leads for future research to further advance knowledge on the importance of industrial clusters in the energy system and to stimulate the implementation of energy synergies.

Hydrogen is widely regarded as a promising carbon-free alternative fuel. However the development of low-emission marine gas turbine combustion systems has been hindered by the associated risks of combustion instability also termed as thermoacoustic oscillations. Although there is sufficient literature on hydrogen fuel and combustion instability systematic reviews addressing the manifestations and mechanisms of these instabilities remain limited. The present study aims to provide a comprehensive review of combustion instabilities in hydrogen-enriched marine gas turbines with a particular focus on elucidating the characteristics and underlying mechanisms. The review begins with a concise overview of recent progress in understanding the fundamental combustion properties of hydrogen and then details various instability phenomena in hydrogen-enriched methane flames. The mechanisms by which hydrogen enrichment affects combustion instabilities are extensively discussed particularly in relation to the feedback loop in thermoacoustic combustion systems. The paper concludes with a summary of the key combustion instability challenges associated with hydrogen addition to methane flames and offers prospects for future research. In summary the review highlights the interaction between hydrogenenriched methane flames and thermoacoustic phenomena providing a foundation for the development of stable low-emission combustion systems in industrial marine applications incorporating hydrogen enrichment.

Algeria’s transition toward sustainable energy requires the exploitation of its abundant solar and wind resources for green hydrogen production. This study assesses the technoeconomic feasibility of an off-grid PV/wind hybrid system integrated with a hydrogen subsystem (electrolyzer fuel cell and hydrogen storage) to supply both electricity and hydrogen to decentralized sites in Algeria. Using HOMER Pro five representative Algerian regions were analyzed accounting for variations in solar irradiation wind speed and groundwater availability. A deferrable water-extraction and treatment load was incorporated to model the water requirements of the electrolyzer. In addition a comprehensive sensitivity analysis was conducted on solar irradiation wind speed and the capital costs of PV panels and wind turbines to capture the effects of renewable resource and investment cost fluctuations. The results indicate significant regional variation with the levelized cost of energy (LCOE) ranging from 0.514 to 0.868 $/kWh the levelized cost of hydrogen (LCOH) between 8.31 and 12.4 $/kg and the net present cost (NPC) between 10.28 M$ and 17.7 M$ demonstrating that all cost metrics are highly sensitive to these variations.

The development of durable and efficient catalysts capable of driving both hydrogen and oxygen evolution reactions is essential for advancing sustainable hydrogen production through overall water electrolysis. In this study we developed a corrosion-mediated approach where Ni ions originate from the self-corrosion of the nickel foam (NF) substrate to construct Pt-modified NiFe layered double hydroxide (Pt-NiFeOxHy@NiFe-LDH) under ambient conditions. The obtained catalyst exhibits a hierarchical architecture with abundant defect sites which favor the uniform distribution of Pt clusters and optimized electronic configuration. The Pt-NiFeOxHy@NiFe-LDH catalyst constructed through the interaction between Pt sites and defective NiFe layered double hydroxide (NiFe-LDH) demonstrates remarkable hydrogen evolution reaction (HER) activity delivering an overpotential as low as 29 mV at a current density of 10 mA·cm−2 and exhibiting a small tafel slope of 34.23 mV·dec−1 in 1 M KOH together with excellent oxygen evolution reaction (OER) performance requiring only 252 mV to reach 100 mA·cm−2 . Moreover the catalyst demonstrates outstanding activity and durability in alkaline seawater maintaining stable operation over long-term tests. The Pt-NiFeOxHy@NiFe-LDH electrode when integrated into a two-electrode system demonstrates operating voltages as low as 1.42 and 1.51 V for current densities of 10 and 100 mA·cm−2 respectively and retains outstanding stability under concentrated alkaline conditions (6 M KOH 70 ◦C). Overall this work establishes a scalable and economically viable pathway toward high-efficiency bifunctional electrocatalysts and deepens the understanding of Pt-LDH interfacial synergy in promoting water-splitting catalysis.

In response to the growing global interest in hydrogen as an energy carrier this study provides the first attempt to develop a baseline inventory of U.S. hydrogen emissions from production distribution and storage. The scope of this study was limited to pure hydrogen emissions and excludes emissions from low purity hydrogen streams and carriers. A detailed literature search was conducted utilizing various greenhouse gas emissions inventory protocol principles and guidelines to consolidate a list of activity data and emission factors. The best available activity data and emission factors were then selected via a Multi-Criteria-Based Decision Making Method named Technique for Order Preference by Similarity to Ideal Solution or modelled using best-engineering estimates. The study estimated total U.S. hydrogen emissions of 0.063 MMTA with emission bounds ranging from 0.02 to 0.11 MMTA. Given the total estimated H2 production capacity of 7.97 MMTA the study estimates a total U.S. hydrogen emission rate for production distribution and storage of 0.79% (0.26%–1.32%). To reduce the uncertainty in the estimated total hydrogen emissions future work should be conducted to measure facility-level hydrogen emission factors across multiple sectors. The inventory framework developed in this study can serve as a living document that can be updated and enhanced as more empirical data is obtained. This study also provides detailed insights regarding key emission or leakage sources and causes from each supply chain stage. The insights and conclusions from this study can provide direction for hydrogen production companies and safety professionals as they develop hydrogen emission mitigation measures and controls.

Driven by carbon neutrality goals electric–hydrogen coupled virtual power plants (EHCVPPs) integrate renewable hydrogen production with power system flexibility resources emerging as a critical technology for large-scale renewable integration. As distributed energy resources (DERs) within EHCVPPs diversify heterogeneous resources generate diversified market values. However inadequate benefit allocation mechanisms risk reducing participation incentives destabilizing cooperation and impairing operational efficiency. To address this benefit allocation must balance fairness and efficiency by incorporating DERs’ regulatory capabilities risk tolerance and revenue contributions. This study proposes a multi-stage benefit allocation framework incorporating risk–reward tradeoffs and an enhanced optimization model to ensure sustainable EHCVPP operations and scalability. The framework elucidates bidirectional risk–reward relationships between DERs and EHCVPPs. An individualized risk-adjusted allocation method and correction mechanism are introduced to address economic-centric inequities while a hierarchical scheme reduces computational complexity from diverse DERs. The results demonstrate that the optimized scheme moderately reduces high-risk participants’ shares increasing operator revenue by 0.69% demand-side gains by 3.56% and reducing generation-side losses by 1.32%. Environmental factors show measurable yet statistically insignificant impacts. The framework meets stakeholders’ satisfaction and minimizes deviation from reference allocations.

Hybrid Renewable Energy Systems (HRESs) are a practical solution for providing reliable low-carbon electricity to off-grid and remote communities. This review examines the role of energy storage within HRESs by systematically comparing electrochemical mechanical thermal and hydrogen-based technologies in terms of technical performance lifecycle cost operational constraints and environmental impact. We synthesize findings from implemented off-grid projects across multiple countries to evaluate real-world performance metrics including renewable fraction expected energy not supplied (EENS) lifecycle cost and operation & maintenance burdens. Special attention is given to the emerging role of hydrogen as a long-term and cross-sector energy carrier addressing its technical regulatory and financial barriers to widespread deployment. In addition the paper reviews real-world implementations of off-grid HRES in various countries summarizing practical outcomes and lessons for system design and policy. The discussion also includes recent advances in metaheuristic optimization algorithms which have improved planning efficiency system reliability and cost-effectiveness. By combining technological operational and policy perspectives this review identifies current challenges and future directions for developing sustainable resilient and economically viable HRES that can accelerate equitable electrification in remote areas. Finally the review outlines key limitations and future directions calling for more systematic quantitative studies long-term field validation of emerging technologies and the development of intelligent Artificial Intelligence (AI)-driven energy management systems within broader socio-techno-economic frameworks. Overall this work offers concise insights to guide researchers and policymakers in advancing the practical deployment of sustainable and resilient HRES.

This study enhances regional integrated energy systems by proposing a Stackelberg planning–operation model with seasonal hydrogen storage addressing source–network separation. An equilibrium algorithm is developed that integrates a competitive search routine with mixed-integer optimization. In the price–energy game framework the hydrogen storage operator is designated as the leader while energy producers load aggregators and storage providers act as followers facilitating a distributed collaborative optimization strategy within the Stackelberg game. Using an industrial park in northern China as a case study the findings reveal that the operator’s initiative results in a revenue increase of 38.60% while producer profits rise by 6.10% and storage-provider profits surge by 108.75%. Additionally renewable accommodation reaches 93.86% reflecting an absolute improvement of 20.60 percentage points. Total net energy imbalance decreases by 55.70% and heat-loss load is reduced by 31.74%. Overall the proposed approach effectively achieves cross-seasonal energy balancing and multi-party gains providing an engineering-oriented reference for addressing energy imbalances in regional integrated energy systems.

This study presents an innovative approach to the production of hydrogen from liquids following hydrothermal treatment of biowaste offering a potential solution for renewable energy generation and waste management. By combining biological and hydrothermal processes the efficiency of H2 production can be significantly improved contributing to a reduced carbon footprint and lower reliance on fossil fuels. The inoculum used was fermented sludge from a wastewater treatment plant which had been thermally pretreated to enhance microbial activity towards hydrogen production. Kitchen waste consisting mainly of plant-derived materials (vegetable matter) was used as a substrate. The process was conducted in batch 1-L bioreactors. The results showed that higher pretreatment temperatures (up to 180 ◦C) increased the hydrolysis of compounds and enhanced H2 production. However temperatures above 180 ◦C resulted in the formation of toxic compounds such as catechol and hydroquinone which inhibited H2 production. The highest hydrogen production was achieved at 180 ◦C (approximately 66 mL H2/gTVSKW). The standard Gompertz model was applied to describe the process kinetics and demonstrated an excellent fit with the experimental data (R2 = 0.99) confirming the model’s suitability for optimizing H2 production. This work highlights the potential of combining hydrothermal and biological processes to contribute to the development of sustainable energy systems within the circular economy.

The development of efficient and sustainable hydrogen storage materials is a key challenge for realizing hydrogen as a clean and flexible energy carrier. Among various options metal hydrides offer high volumetric storage density and operational safety yet their application is limited by thermodynamic kinetic and compositional constraints. In this work we investigate the potential of machine learning (ML) to predict key thermodynamic properties—equilibrium plateau pressure enthalpy and entropy of hydride formation—based solely on alloy composition using Magpie-generated descriptors. We significantly expand an existing experimental dataset from ~400 to 806 entries and assess the impact of dataset size and data augmentation using the PADRE algorithm on model performance. Models including Support Vector Machines and Gradient Boosted Random Forests were trained and optimized via grid search and cross-validation. Results show a marked improvement in predictive accuracy with increased dataset size while data augmentation benefits are limited to smaller datasets and do not improve accuracy in underrepresented pressure regimes. Furthermore clustering and cross-validation analyses highlight the limited generalizability of models across different material classes though high accuracy is achieved when training and testing within a single hydride family (e.g. AB2). The study demonstrates the viability and limitations of ML for accelerating hydride discovery emphasizing the importance of dataset diversity and representation for robust property prediction.