Greece

The Middle East and North Africa region has not played a major role in climate action so far and several countries depend economically on fossil fuel exports. However this is a region with vast solar energy resources which can be exploited affordably for power generation and hydrogen production at scale to eventually reach carbon neutrality. In this paper we elaborate on the case of the United Arab Emirates and explore the aspirations and feasibility of its net-zero by 2050 target. While we affirm the concept per se we also highlight the technological complexity and economic dimensions that accompany such transformation. We expect the UAE’s electricity demand to triple between today and 2050 and the annual green hydrogen production is expected to reach 3.5 Mt accounting for over 40% of the electricity consumption. Green hydrogen will provide power-to-fuel solutions for aviation maritime transport and hard-to-abate industries. At the same time electrification will intensify—most importantly in road transport and low-temperature heat demands. The UAE can meet its future electricity demands primarily with solar power followed by natural gas power plants with carbon capture utilization and storage while the role of nuclear power in the long term is unclear at this stage.

This paper addresses public acceptance of a proposed sub-regional hydrogen– electric aviation service reporting initial empirical evidence from the UK HEART project. The objective was to assess public acceptance of a wide range of service features including hydrogen power electric motors and pilot assistance automation in the context of an ongoing realisable commercial plan. Both qualitative and quantitative data collection instruments were leveraged including focus groups and stakeholder interviews as well as the questionnaire-based Scottish National survey coupled with the advanced discretechoice modelling of the data. The results from each method are presented compared and contrasted focusing on the strength reliability and validity of the data to generate insights into public acceptance. The findings suggest that public concerns were tempered by an incomplete understanding of the technology but were interpretable in terms of key service elements. Respondents’ concerns and opinions centred around hydrogen as a fuel singlepilot automation safety and security disability and inclusion environmental impact and the perceived usefulness of novel service features such as terminal design automation and sustainability. The latter findings were interpreted under a joint framework of technology acceptance theory and the diffusion of innovation. From this we drew key insights which were presented alongside a discussion of the results.

The challenge of achieving net-zero CO2 emissions will require a significant scaling up of the production of several raw materials that are critical for decarbonizing the global economy. In contrast metal extraction processes utilize carbon as a reducing agent which is oxidized to CO2 resulting in considerable emissions and having a negative impact on climate change. In order to abate their emissions extractive industries will have to go through a profound transformation including switching to alternative climateneutral energy and feedstock sources. This paper presents the authors’ perspectives for consideration in relation to the H2 potential for direct reduction of oxide and sulfide ores. For each case scenario the reduction of CO2 emissions is analyzed and a breakthrough route for H2S decomposition is presented which is a by-product of the direct reduction of sulfide ores with H2. Electrified indirect-fired metallurgical kiln advantages are also presented a solution that can substitute fossil fuel-based heating technologies which is one of the main backbones of industrial processes currently applied to the extractive industries.

The present research work investigates the performance of two large-scale energy storage technologies: hydro-pumped storage (HPS) and green hydrogen production within a hybrid renewable energy system (HRES) developed for Kefalonia Island Greece. Given the island’s seasonal water and electricity shortages driven by summer demand and limited infrastructure the goal is to identify which storage option better supports local autonomy. Two scenarios differing only in storage method were simulated using identical wind input and desalination setup. Performance was evaluated based on climate and demand data focusing on water and electricity needs. Both scenarios achieved 99.9 % potable water coverage. The HPS system exhibited notably higher energy efficiency (67 %) compared to hydrogen (33 %) and produced slightly more desalinated water reaching 18157791 m3 versus 17986544 m3 respectively. Electricity demand coverage reached 77.8 % with HPS and 76.0 % with hydrogen while irrigation demand was met by 80.2 % and 79.4 % respectively. Seasonal storage analysis revealed pronounced summer depletion in both cases due to high demand and low wind availability with HPS recovering faster and maintaining higher storage levels owing to lower energy losses. The comparison underscores the need for storage strategies adapted to island-specific water and energy dynamics. HPS is more efficient for short-to-medium-term needs while green hydrogen offers potential for long-duration storage and deeper decarbonization.

Hydrogen valleys are encompassed within a defined geographical region with various technologies across the entire hydrogen value chain. The scope of this study is to analyze and assess the different hydrogen technologies for their application within the hydrogen valley context. Emphasizing on the coupling of renewable energy sources with electrolyzers to produce green hydrogen this study is focused on the most prominent electrolysis technologies including alkaline proton exchange membrane and solid oxide electrolysis. Moreover challenges related to hydrogen storage are explored alongside discussions on physical and chemical storage methods such as gaseous or liquid storage methanol ammonia and liquid organic hydrogen carriers. This article also addresses the distribution of hydrogen within valley operations especially regarding the current status on pipeline and truck transportation methods. Furthermore the diverse applications of hydrogen in the mobility industrial and energy sectors are presented showcasing its potential to integrate renewable energy into hard-to-abate sectors.

The escalating urgency to address climate change has sparked unprecedented interest in green hydrogen as a clean energy carrier. The intermittent nature of Renewable Energy Sources (RES) like wind and solar can introduce unpredictability into the energy supply potentially causing mismatches in the power grid. To this end green hydrogen production can provide a solution by enhancing system flexibility thereby accommodating the fluctuations and stochastic characteristics of RES. Furthermore green hydrogen could play a pivotal role in decarbonizing hard-to-abate sectors and promoting sector coupling. This research article endeavors to delve into this subject by developing a dynamic techno-economic analysis tool capable of flexibly assessing the optimal setup of Alkaline (AEL) electrolysis coupled with RES in a specific region or hub. The focus lies on achieving costeffectiveness efficiency and sustainable production of green hydrogen. The tool leverages a comprehensive dataset covering a full year of hourly data on both renewable electricity production from intermittent RES and wholesale electricity market prices alongside customizable inputs from users. It can be applied across various scenarios including direct coupling with dedicated RES plants and hybrid configurations utilizing the electricity grid as a backup source. The model optimizes RES electrolyser and hydrogen storage capacities to minimize the Levelized Cost of Hydrogen (LCOH) and/or the operational Carbon Intensity (CI) of hydrogen produced. The tool is applied within a real-world application study in the framework of the TRIERES Hydrogen Valley Project which is taking shape in Peloponnese Greece. For the various configurations analysed the LCOH ranges from 7.75 to 12.68 €/kgH2. The cost-optimal system configuration featuring a hybrid RES power supply of 12 MW solar and 19 MW wind energy alongside with 3.5 tonnes of hydrogen storage leads to a minimum LCOH of 7.75 €/kgH2. Subsidies on electrolyser stack and balance of plant CAPEX can reduce LCOH by up to 0.6 €/kgH2.

To achieve the European milestone of climate neutrality by 2050 the decarbonisation of energy-intensive industries is essential. In 2022 global energy-related CO2 emissions increased by 0.9% or 321 Mt reaching a peak of over 36.8 Gt. A large amount of these emissions is the result of fossil fuel usage in the motorised equipment used in mining. Heavy diesel vehicles like excavators wheel loaders and dozers are responsible for an estimated annual CO2 emissions of 400 Mt of CO2 accounting for approximately 1.1% of global CO2 emissions. In addition exhaust gases of CO2 and NOx endanger the personnel’s health in all mining operations especially in underground environments. To tackle these environmental concerns and enhance environmental health extractive industries are focusing on replacing fossil fuels with alternative fuels of low or zero CO2 emissions. In mining the International Council on Mining and Metals has committed to achieving net zero emissions by 2050 or earlier. Of the various alternative fuels hydrogen (H2 ) has seen a considerable rise in popularity in recent years as H2 combustion accounts for zero CO2 emissions due to the lack of carbon in the burning process. When combusted with pure oxygen it also accounts for zero NOx formation and near-zero emissions overall. To this end this study aims to examine the overall environmental performance of H2 -powered motorised equipment compared to conventional fossil fuel-powered equipment through Life Cycle Assessment. The assessment was conducted using the commercial software Sphera LCA for Experts following the conventionally used framework established by ISO 14040:2006 and 14044:2006/A1:2018 and the International Life Cycle Data Handbook consisting of (1) the goal and scope definition (2) the Life Cycle Inventory (LCI) preparation (3) the Life Cycle Impact Assessment (LCIA) and (4) the interpretation of the results. The results will offer an overview to support decision-makers in the sector.

Industrial applications of hydrogen are key to the transition towards a sustainable lowcarbon economy. Hydrogen has the potential to decarbonize industrial sectors that currently rely heavily on fossil fuels. Hydrogen with its unique and versatile properties has several in-industrial applications that are fundamental for sustainability and energy efficiency such as the following: (i) chemical industry; (ii) metallurgical sector; (iii) transport; (iv) energy sector; and (v) agrifood sector. The development of a bibliometric analysis of industrial hydrogen applications in Europe is crucial to understand and guide developments in this emerging field. Such an analysis can identify research trends collaborations between institutions and countries and the areas of greatest impact and growth. By examining the scientific literature and comparing it with final hydrogen consumption in different regions of Europe the main actors and technologies that are driving innovation in industrial hydrogen use on the continent can be identified. The results obtained allow for an assessment of the knowledge gaps and technological challenges that need to be addressed to accelerate the uptake of hydrogen in various industrial sectors. This is essential to guide future investments and public policies towards strategic areas that maximize the economic and environmental impact of industrial hydrogen applications in Europe.

A sustainable future hydrogen economy hinges on the development of green hydrogen and the shift away from grey hydrogen but this is highly reliant on reducing production costs which are currently too high for green hydrogen to be competitive. This study predicts the cost trajectory of alkaline and proton exchange membrane (PEM) electrolyzers based on ongoing research and development (R&D) scale effects and experiential learning consequently influencing the levelized cost of hydrogen (LCOH) projections. Electrolyzer capital costs are estimated to drop to 88 USD/kW for alkaline and 60 USD/kW for PEM under an optimistic scenario by 2050 or 388 USD/kW and 286 USD/kW respectively under a pessimistic scenario with PEM potentially dominating the market. Through a combination of declining electrolyzer costs and a levelized cost of electricity (LCOE) the global LCOH of green hydrogen is projected to fall below 5 USD/kgH2 for solar onshore and offshore wind energy sources under both scenarios by 2030. To facilitate a quicker transition the implementation of financial strategies such as additional revenue streams a hydrogen/carbon credit system and an oxygen one (a minimum retail price of 2 USD/kgO2 ) and regulations such as a carbon tax (minimum 100 USD/tonCO2 for 40 USD/MWh electricity) and a contract-for-difference scheme could be pivotal. These initiatives would act as financial catalysts accelerating the transition to a greener hydrogen economy.

The use of liquid hydrogen in maritime applications is expected to grow in the coming years in order to meet the decarbonisation goals that EU countries and countries worldwide have set for 2050. In this context The Norwegian Public Roads Administration commissioned large-scale LH2 dispersion and explosion experiments both indoors and outdoors which were conducted by DNG GL in 2019 to better understand safety aspects of LH2 in the maritime sector. In this work the DNV unignited outdoor and indoor tests have been simulated and compared with the experiments with the aim to validate the ADREA-HF Computational Fluid Dynamics (CFD) code in maritime applications. Three tests two outdoors and one indoors were chosen for the validation. The outdoor tests (test 5 and 6) involved liquid hydrogen release vertically downwards and horizontal to simulate an accidental leakage during bunkering. The indoor test (test 9) involved liquid hydrogen release inside a closed room to simulate an accident inside a tank connection space (TCS) connected to a ventilation mast.