Publications

This report by the Clean Energy Technology Observatory (CETO) provides an updated strategic analysis of the EU clean energy technology sector. The EU's renewable share in gross final energy consumption rose to 24.5% in 2023 and to 44.7% of gross electricity consumption. The electrification rate however has remained almost unchanged at 26% over the decade to 2023 indicating slow progress on decarbonisation of transport and heating sectors. The EU renewable energy industry saw growth in turnover and gross value added in 2023 outperforming the overall economy. However the production value of clean energy technologies declined in some areas such as bioenergy PV and hydrogen electrolyser production. EU public investment in energy research and innovation has increased but it remains lower as a share of GDP compared to other major economies. Employment in the renewable energy sector reached 1.7 million in 2022 growing at a faster rate than the economy as a whole. The clean energy sector however faces challenges in manufacturing. A new sustainability assessment framework has been applied for clean energy technologies highlighting the need for a harmonized basis for comparing results. The report also underscores the general need to improve data quality and timeliness to better inform policy makers and investors.

To mitigate challenges arising from renewable energy volatility and multi-energy load uncertainty this paper introduces a dynamic hydrogen blending (DHB) strategy for an integrated energy system. The strategy is categorized into Continuous Hydrogen Blending (CHB) and Time-phased Hydrogen Blending (THB) based on the temporal variations in the hydrogen blending ratio. To evaluate the regulatory effect of DHB on uncertainty a datadriven distributionally robust optimization method is employed in the day-ahead stage to manage system uncertainties. Subsequently a hierarchical model predictive control framework is designed for the intraday stage to track the day-ahead robust scheduling outcomes. Experimental results indicate that the optimized CHB ratio exhibits step characteristics closely resembling the THB configuration. In terms of cost-effectiveness CHB reduces the day-ahead scheduling cost by 0.87% compared to traditional fixed hydrogen blending schemes. THB effectively simplifies model complexity while maintaining a scheduling performance comparable to CHB. Regarding tracking performance intraday dynamic hydrogen blending further reduces upper- and lower-layer tracking errors by 4.25% and 2.37% respectively. Furthermore THB demonstrates its advantage in short-term energy regulation effectively reducing tracking errors propagated from the upper layer MPC to the lower layer resulting in a 2.43% reduction in the lower-layer model’s tracking errors.

In response to the greenhouse gas (GHG) reduction targets set by the Paris Agreement green hydrogen has become a key solution for global decarbonisation. However research on the design of green hydrogen production facilities remains limited particularly in Brazil. This study bridges this gap by developing a comprehensive design for a green hydrogen production plant powered by an 81 MW photovoltaic (PV) system in Ceará Brazil. The facility layout equipment sizing and resource requirements were determined using the Systematic Layout Planning (SLP) method based on the available energy for daily hydrogen production. The design also integrates safety regulations including local standards in Ceará as well as raw material needs and production capacity. This study delivers a detailed facility layout specifying equipment placement and capacity based on the PV plant’s output while ensuring compliance with safety protocols. This research contributes to the green hydrogen literature by providing a structured methodology for facility design serving as a reference for future projects and fostering the advancement of green hydrogen technology particularly in developing countries.

The development of liquid hydrogen storage systems is a key aspect to enable future clean air transportation. However safety analysis research for such systems is still limited and is hindered by the limited experience with liquid hydrogen storage in aviation. This paper presents the outcomes of a preliminary safety assessment applied to this new type of storage system accounting for the hazards of hydrogen. The methodology developed is based on hazard identification and frequency evaluation across all system features to identify the most critical safety concerns. Based on the safety assessment a set of safety recommendations concerning different subsystems of the liquid hydrogen storage system is proposed identifying hazard scopes and necessary mitigation actions across various system domains. The presented approach has been proven to be suitable for identifying essential liquid hydrogen hazards despite the novelty of the technology and for providing systematic design recommendations at a relatively early design stage.

This study investigates the potential for establishing a self-sufficient renewable hydrogen production facility utilising a floating photovoltaic (FPV) system on an artificial irrigation reservoir located in a small municipality in southern Italy. The analysis examines the impact of different system configurations and operating conditions on the technical economic and environmental performance with a particular focus on hydrogen production and water conservation resulting from reduced evaporation. Different sizes of the FPV plant are considered with and without a tracking system. The electrolyser performance is evaluated under both fixed and variable load conditions also considering the integration of battery storage to ensure consistent operation. The findings indicate that the adoption of the largest FPV plant can result in the conservation of approximately 1.87 million m3 of water annually while simultaneously producing up to 4199 tons of hydrogen per year in variable load mode—more than twice the output compared to fixed load conditions. Although battery integration increases hydrogen production it also leads to higher investment and maintenance costs. Therefore the variable load operation emerges as the most economically viable option reducing the levelized cost of hydrogen (LCOH) to €13.18/kg a 26 % reduction compared to fixed load operation. Moreover the implementation of a vertical axis tracking system leads to only marginal LCOH reductions (maximum 2.2 %) and does not justify the additional complexity. In all tested scenarios the system proves to be self-sustaining. Given the case study’s location in southern Italy—where a pilot project for fuel cell–battery hybrid trains is underway—the hydrogen produced is assumed to be used for railway applications as a possible offtaker. The analysis shows that the potential of the system in terms of hydrogen production is much higher (tens of times) than the estimated demand of the present hydrogen railway configuration thus suggesting that a significant expansion of the number of trains and routes served could be considered. Although this work is based on a specific case study its key findings are potentially replicable in other contexts—particularly in Mediterranean or semi-arid regions where water scarcity may otherwise act as a limiting factor for the deployment of hydrogen production systems.

Fuel cells have become a fundamental technology in the development of clean energy systems playing a vital role in the global shift toward a low-carbon future. With the growing need for sustainable hydrogen production perfluoro sulfonic acid (PFSA) ionomer membranes play a critical role in optimizing green hydrogen technologies and fuel cells. This study aims to investigate the effects of different environmental and solvent treatments on the chemical and physical properties of Nafion N−115 membranes to evaluate their suitability for both hydrogen production in proton exchange membrane (PEM) electrolyzers and hydrogen utilization in fuel cells supporting integrated applications in the local and global green hydrogen economy. To achieve this Nafion N−115 membranes were partially dissolved in various solvent mixtures including ethanol/isopropanol (EI) isopropanol/water (IW) dimethylformamide/N-methyl-2-pyrrolidone (DN) and ethanol/methanol/isopropanol (EMI) evaluated under water immersion and thermal stress and characterized for chemical stability mechanical strength water uptake and proton conductivity using advanced electrochemical and spectroscopic techniques. The results demonstrated that the EMI-treated membrane showed the highest proton conductivity and maintained its structural integrity making it the most promising for hydrogen electrolysis applications. Conversely the DN-treated membrane exhibited reduced stability and lower conductivity due to solvent-induced degradation. This study highlights the potential of EMI as an optimal solvent mixture for enhancing PFSA membranes performance in green hydrogen production contributing to the advancement of sustainable energy solutions.

: Hydrogen is a clean non-polluting fuel and a key player in decarbonizing the energy sector. Interest in hydrogen production has grown due to climate change concerns and the need for sustainable alternatives. Despite advancements in waste-to-hydrogen technologies the efficient conversion of mixed plastic waste via an integrated thermochemical process remains insufficiently explored. This study introduces a novel multi-stage pyrolysis-reforming framework to maximize hydrogen yield from mixed plastic waste including polyethylene (HDPE) polypropylene (PP) and polystyrene (PS). Hydrogen yield optimization is achieved through the integration of two water–gas shift reactors and a pressure swing adsorption unit enabling hydrogen production rates of up to 31.85 kmol/h (64.21 kg/h) from 300 kg/h of mixed plastic wastes consisting of 100 kg/h each of HDPE PP and PS. Key process parameters were evaluated revealing that increasing reforming temperature from 500 ◦C to 1000 ◦C boosts hydrogen yield by 83.53% although gains beyond 700 ◦C are minimal. Higher reforming pressures reduce hydrogen and carbon monoxide yields while a steam-to-plastic ratio of two enhances production efficiency. This work highlights a novel scalable and thermochemically efficient strategy for valorizing mixed plastic waste into hydrogen contributing to circular economy goals and sustainable energy transition.

Ports are critical hubs in the global supply chain yet they face mounting challenges in achieving carbon neutrality. Port Integrated Multi-Energy Systems (PIMESs) offer a comprehensive solution by integrating renewable energy sources such as wind photovoltaic (PV) hydrogen and energy storage with traditional energy systems. This study examines the implementation of a real-word PIMES showcasing its effectiveness in reducing energy consumption and emissions. The findings indicate that in 2024 the PIMES enabled a reduction of 1885 tons of CO2 emissions with wind energy contributing 84% and PV 16% to the total decreases. The energy storage system achieved a charge–discharge efficiency of 99.15% while the hydrogen production system demonstrated an efficiency of 63.34% producing 503.87 Nm3/h of hydrogen. Despite these successes challenges remain in optimizing renewable energy integration expanding storage capacity and advancing hydrogen technologies. This paper highlights practical strategies to enhance PIMESs’ performances offering valuable insights for policymakers and port authorities aiming to balance energy efficiency and sustainability and providing a blueprint for carbon-neutral port development worldwide.

The purpose of this Hydrogen Pipeline System COP is to provide guidance based on current knowledge for the design construction and operation of transmission pipeline systems transporting gaseous hydrogen or blends of hydrogen and hydrocarbon fluids.<br/>The objective of the code is to provide guidance for the safe reliable and efficient transportation and storage of hydrogen in transmission pipeline systems that are required to conform to the AS(/NZS) 2885 series. The document also references adoption of other international codes where suitable guidance is available.<br/>This document is intended to be updated with revised design criteria and methods as research and experience improves the understanding of hydrogen service in transmission pipelines. Although the CoP may be further developed into a published standard in the future within the AS(/NSZ) 2885 series framework this current revision of the CoP is not equivalent to a formal published Australian standard. The document also includes expanded commentary and background information as an informative code of practice that is more extensive than is typically covered in a standard.

Hydrogen is emerging as a crucial energy source in the global effort to reduce dependence on fossil fuels and meet climate goals. Integrating hydrogen into Integrated Assessment Models (IAMs) is essential for understanding its potential and guiding policy decisions. These models simulate various energy scenarios assess hydrogen’s impact on emissions and evaluate its economic viability. However uncertainties surrounding hydrogen technologies must be effectively addressed in their modeling. This review examines how different IAMs incorporate hydrogen technologies and their implications for decarbonization strategies and policy development considering underlying uncertainties. We begin by analyzing the configuration of the hydrogen supply chain focusing on production logistics distribution and utilization. The modeling characteristics of hydrogen integration in 12 IAM families are explored emphasizing hydrogen’s growing significance in stringent climate mitigation scenarios. Results from the literature and the AR6 database reveal gaps in the modeling of the hydrogen supply chain particularly in storage transportation and distribution. Model characteristics are critical in determining hydrogen’s share within the energy portfolio. Additionally this study underscores the importance of addressing both parametric and structural uncertainties in IAMs which are often underestimated leading to varied outcomes regarding hydrogen’s role in decarbonization strategies.