France

This paper evaluates the potential of grid services in France Italy Norway and Spain to provide an alternative income for electrolysers producing hydrogen from wind power. Grid services are simulated with each country's data for 2017 for energy prices grid services and wind power profiles from relevant wind parks. A novel metric is presented the value of curtailed hydrogen which is independent from several highly uncertain parameters such as electrolyser cost or hydrogen market price. Results indicate that grid services can monetise the unused spare capacity of electrolyser plants improving their economy in the critical deployment phase. For most countries up-regulation yields a value of curtailed hydrogen above 6 V/kg over 3 times higher than the EU's 2030 price target (without incentives). However countries with large hydro power resources such as Norway yield far lower results below 2 V/kg. The value of curtailed hydrogen also decreases with hydrogen production corresponding to the cases of symmetric and down-regulation.

Much has been learned about natural hydrogen (H2) seepages and accumulation but present knowledge of hydrogen behavior in the crust is so limited that it is not yet possible to consider exploitation of this resources. Hydrogen targeting requires a shift in the long-standing paradigms that drive oil and gas exploration. This paper describes the foundation of an integrated source-to-sink view of the hydrogen cycle and propose preliminary practical guidelines for hydrogen exploration.

Hydrogen is a key energy carrier that could play a crucial role in the transition to a low-carbon economy. Hydrogen-related technologies are considered flexible solutions to support the large-scale implementation of intermittent energy supply from renewable sources by using renewable energy to generate green hydrogen during periods of low demand. Therefore a short-term increase in demand for hydrogen as an energy carrier and an increase in hydrogen production are expected to drive demand for large-scale storage facilities to ensure continuous availability. Owing to the large potential available storage space underground hydrogen storage offers a viable solution for the long-term storage of large amounts of energy. This study presents the results of a survey of potential underground hydrogen storage sites in Italy carried out within the H2020 EU Hystories “Hydrogen Storage In European Subsurface” project. The objective of this work was to clarify the feasibility of the implementation of large-scale storage of green hydrogen in depleted hydrocarbon fields and saline aquifers. By analysing publicly available data mainly well stratigraphy and logs we were able to identify onshore and offshore storage sites in Italy. The hydrogen storage capacity in depleted gas fields currently used for natural gas storage was estimated to be around 69.2 TWh.

To cope with climate change emerging fuels- hydrogen ammonia and methanol- have been proposed as promising energy carriers that will replace part of the liquefied natural gas (LNG) in future maritime scenarios. Energy efficiency is an important indicator for evaluating the system but the maritime supply system for emerging fuels has yet to be revealed. In this study the energy efficiency of the maritime supply chain of hydrogen ammonia methanol and natural gas is investigated considering processes including production storage loading transport and unloading. A sensitivity analysis of parameters such as ambient temperature storage time pipeline length and sailing time is also carried out. The results show that hydrogen (2.366%) has the highest daily boil-off gas (BOG) rate and wastes more energy than LNG (0.413%) with ammonia and methanol both being lower than LNG. The recycling of BOG is of great importance to the hydrogen supply chain. When produced from renewable energy sources methanol (98.02%) is the most energy efficient followed by ammonia with hydrogen being the least (89.10%). This assessment shows from an energy efficiency perspective that ammonia and methanol have the potential to replace LNG as the energy carrier of the future and that hydrogen requires efficient BOG handling systems to increase competitiveness. This study provides some inspirations for the design of global maritime supply systems for emerging fuels.

In the framework of the ongoing EMPIR JRP 16ENG01 ‘‘Metrology for Hydrogen Vehicles’’ a main task is to investigate the influence of pressure on the measurement accuracy of Coriolis Mass Flow Meters (CFM) used at Hydrogen Refueling Stations (HRS). At a HRS hydrogen is transferred at very high and changing pressures with simultaneously varying flow rates and temperatures. It is clearly very difficult for CFMs to achieve the current legal requirements with respect to mass flow measurement accuracy at these measurement conditions. As a result of the very dynamic filling process it was observed that the accuracy of mass flow measurement at different pressure ranges is not sufficient. At higher pressures it was found that particularly short refueling times cause significant measurement deviations. On this background it may be concluded that pressure has a great impact on the accuracy of mass flow measurement. To gain a deeper understanding of this matter RISE has built a unique high-pressure test facility. With the aid of this newly developed test rig it is possible to calibrate CFMs over a wide pressure and flow range with water or base oils as test medium. The test rig allows calibration measurements under the conditions prevailing at a 70 MPa HRS regarding mass flows (up to 3.6 kg min−1) and pressures (up to 87.5 MPa).

Ammonia a molecule that is gaining more interest as a fueling vector has been considered as a candidate to power transport produce energy and support heating applications for decades. However the particular characteristics of the molecule always made it a chemical with low if any benefit once compared to conventional fossil fuels. Still the current need to decarbonize our economy makes the search of new methods crucial to use chemicals such as ammonia that can be produced and employed without incurring in the emission of carbon oxides. Therefore current efforts in this field are leading scientists industries and governments to seriously invest efforts in the development of holistic solutions capable of making ammonia a viable fuel for the transition toward a clean future. On that basis this review has approached the subject gathering inputs from scientists actively working on the topic. The review starts from the importance of ammonia as an energy vector moving through all of the steps in the production distribution utilization safety legal considerations and economic aspects of the use of such a molecule to support the future energy mix. Fundamentals of combustion and practical cases for the recovery of energy of ammonia are also addressed thus providing a complete view of what potentially could become a vector of crucial importance to the mitigation of carbon emissions. Different from other works this review seeks to provide a holistic perspective of ammonia as a chemical that presents benefits and constraints for storing energy from sustainable sources. State-of-the-art knowledge provided by academics actively engaged with the topic at various fronts also enables a clear vision of the progress in each of the branches of ammonia as an energy carrier. Further the fundamental boundaries of the use of the molecule are expanded to real technical issues for all potential technologies capable of using it for energy purposes legal barriers that will be faced to achieve its deployment safety and environmental considerations that impose a critical aspect for acceptance and wellbeing and economic implications for the use of ammonia across all aspects approached for the production and implementation of this chemical as a fueling source. Herein this work sets the principles research practicalities and future views of a transition toward a future where ammonia will be a major energy player.

Fuel cells and electric batteries are competing technologies for the energy transition in heavy transportation. We explore the conditions for the survival of a unique technology in the long term. Learning by doing suggests focusing on a single technology while differentiation and decreasing return to scale (cost convexity) favor diversification. Exogenous technical change also plays a role. The interaction between these factors is analyzed in a general model. It is proved that in absence of convexity and exogenous technical change only one technology is used for the whole transition. We then apply this framework to analyze the competition between fuel-cell electric buses (FCEBs) and battery electric buses (BEB) in the European bus sector. There are both learning by doing and exogenous technical change. The model is calibrated and solved. It is shown that the existence of a niche for FCEBs critically depends on the speed at which cost reductions are achieved. The speed depends both on the size of the niche and the rate of learning by doing for FCEBs. Public policies to decentralize the socially optimal trajectory in terms of taxes (carbon) and subsidies (learning by doing) are derived.

The Federal Institute of Metrology METAS developed a Hydrogen Field Test Standard (HFTS) that can be used for field verification and calibration of hydrogen refuelling stations. The testing method is based on the gravimetric principle. The experimental design of the HFTS as well as the description of the method are presented here.

The MultHyFuel project notably aims to produce the data missing for usable risk analysis and mitigation activity for Hydrogen Refuelling Stations (HRS) in a multi-fuel context. In this framework realistic releases of hydrogen that could occur in representative multi-fuel forecourts were studied. These releases can occur inside or outside fuel dispensers and they can interact with a complex environment notably made of parked cars and trucks. This paper is focused on the most critical scenarios that were addressed by a sub-group through the use of Computational Fluid Dynamics (CFD) modelling. Once the corresponding source terms for hydrogen releases were known two stages are followed:<br/>♦ Model Validation – to evaluate the CFD models selected by the task partners and to evaluate their performance through comparison to experimental data.<br/>♦ Realistic Release Modelling – to perform demonstration simulations of a range of critical scenarios.<br/>The CFD models selected for the Model Validation have been tested against measured data for a set of experiments involving hydrogen releases. Each experiment accounts for physical features that are encountered in the realistic cases. The selected experiments include an under-expanded hydrogen jet discharging into the open atmosphere with no obstacles or through an array of obstacles. Additionally a very different set-up was studied with buoyancy-driven releases inside a naturally ventilated enclosure. The results of the Model Validation exercise show that the models produce acceptable solutions when compared to measured data and give confidence in the ability of the models and the modellers to capture the behaviour of the realistic releases adequately. The Realistic Release Modelling phase will provide estimation of the flammable gas cloud volume for a set of critical scenarios and will be described at the second stage.

In recent years the use and development of hydrogen as a carbon-free energy carrier have grown. However as hydrogen is flammable with air safety issues are raised. In the case of ignition especially in confined space the flame can accelerate and reach the detonation regime causing severe structural damage [1].<br/>To assess these safety issues it is required to understand the fluid-structure interaction in the case of a detonation impacting a deformable structure and to quantify and model this interaction [2]. At the CEA (Commissariat à l’énergie atomique et aux energies alternatives) a combustion tube experimental facility [3] for studying the fluid-structure interaction in the case of hydrogen combustion has been developed. Several Photomultipliers and Pressure sensors are placed along the tube to monitor the flame acceleration and the detonation location. A fluid-structure interaction (FSI) module or a non-deformable flange can be placed at the end of the tube. Post-processing of the sensor’s signal will provide insight into the occurring phenomena inside the tube.<br/>Several experimental campaigns have been conducted with various initial conditions and configurations at the end of the tube. In this contribution the experiments resulting in a detonation are presented. First the recorded pressure and velocities will be compared to theoretical values coming from combustion models [4] [5]. Secondly the impulse before and after reflection for thin plate and non-deformable flange will be compared to quantify the energy transmitted to the plate and the influence of the fluid-structure interaction on the reflected shock.