United Kingdom

Power-to-gas is a key area of interest for decarbonisation and increasing flexibility in energy systems as it has the potential both to absorb renewable electricity at times of excess supply and to provide backup energy at times of excess demand. By integrating power-to-gas with the natural gas grid it is possible to exploit the inherent linepack flexibility of the grid and shift some electricity variability onto the gas grid. Furthermore provided the gas injected into the gas grid is low-carbon such as hydrogen from renewable power-to-gas then overall greenhouse gas emissions from the gas grid can be reduced.<br/>This work presents the first review of power-to-gas to consider real-life projects economic assessments and systems modelling studies and to compare them based on scope assumptions and outcomes. The review focuses on power-to-gas for injection into the gas grid as this application has specific economic technical and modelling opportunities and challenges.<br/>The review identified significant interest in and potential for power-to-gas in combination with the gas grid however there are still challenges to overcome to find profitable business cases and manage local and system-wide technical issues. Whilst significant modelling of power-to-gas has been undertaken more is needed to fully understand the impacts of power-to-gas and gas grid injection on the operational behaviour of the gas grid taking into account dynamic and spatial effects.

The establishment of a strong hydrogen economy nationally and locally is a very real opportunity and one that is rapidly becoming within reach.<br/>This report presents a vision for the role that hydrogen could play specifically in South Yorkshire (UK) to help meet carbon reduction targets and contribute to the health and economic prosperity of the region.<br/>It also highlights five themes as levers of growth and explores potential actions and collaborations as well as a list of ambitions for future hydrogen projects. Hydrogen can be used in transport industry and heating. Synergies need exploring for example the by-product of oxygen from hydrogen production can be used by industry. Aggregating opportunities is important in developing a hydrogen economy.<br/>The report concludes with a call to action to build momentum for the South Yorkshire hydrogen economy and accelerate the drive to net zero emissions particularly in the most challenging sectors.<br/>This South Yorkshire specific report supports our global thought piece Establishing a Hydrogen Economy: The future of energy 2035

We investigate the influence of microstructural traps in hydrogen-assisted fatigue crack growth. To this end a new formulation combining multi-trap stress-assisted diffusion mechanism-based strain gradient plasticity and a hydrogen- and fatigue-dependent cohesive zone model is presented and numerically implemented. The results show that the ratio of loading frequency to effective diffusivity governs fatigue crack growth behaviour. Increasing the density of beneficial traps not involved in the fracture process results in lower fatigue crack growth rates. The combinations of loading frequency and carbide trap densities that minimise embrittlement susceptibility are identified providing the foundation for a rational design of hydrogen-resistant alloys.

The H21 Leeds City Gate project is a study with the aim of determining the feasibility from both a technical and economic viewpoint of converting the existing natural gas network in Leeds one of the largest UK cities to 100% hydrogen. The project has been designed to minimise disruption for existing customers and to deliver heat at the same cost as current natural gas to customers. The project has shown that:

• The gas network has the correct capacity for such a conversion
• It can be converted incrementally with minimal disruption to customers
• Minimal new energy infrastructure will be required compared to alternatives
• The existing heat demand for Leeds can be met via steam methane reforming and salt cavern storage using technology in use around the world today

The project has provided costs for the scheme and has modelled these costs in a regulatory finance model. In addition the availability of low-cost bulk hydrogen in a gas network could revolutionise the potential for hydrogen vehicles and via fuel cells support a decentralised model of combined heat and power and localised power generation.

This report and any attachment is freely available on the ENA Smarter Networks Portal here. IGEM Members can download the report and any attachment directly by clicking on the pdf icon above.

As part of FCH-JU funded HyCoRA project running from 2014 to 2017 28 gaseous and 13 particulate samples were collected from hydrogen refuelling stations in Europe. Samples were collected with commercial sampling instruments and analysis performed in compliance with prevailing fuel quality standards. Sampling was conducted with focus on diversity in feedstock as well as commissioning date of the HRS. Results indicate that the strategy for sampling was good. No evidence of impurity cross-over was observed. Parallel samples collected indicate some variation in analytical results. It was however found that fuel quality was generally good. Fourteen analytical results were in violation with the fuel tolerance limits. Therefore eight or 29% of the samples were in violation with the fuel quality requirements. Nitrogen oxygen and organics were the predominant impurities quantified. Particulate impurities were found to be within fuel quality specifications. No correlation between fuel quality and hydrogen feedstock or HRS commissioning date was found. Nitrogen to oxygen ratios gave no indication of samples being contaminated by air. A comparison of analytical results between two different laboratories were conducted. Some difference in analytical results were observed.

The European Regulations on type-approval of hydrogen vehicles require thermally-activated pressure relief device (TPRD) to be installed on hydrogen onboard storage tanks to release its content in a fire event to prevent its catastrophic rupture. The aim of this study is to develop a model for design of an inherently safer system TPRD-storage tank. Parameters of tank materials and hydrogen external heat flux from the fire to the tank wall TPRD diameter time to initiate TPRD are input parameters of the model. The energy conservation equation and real gas equation of state are employed to describe the dynamic behaviour of the system. The under-expanded jet theory developed previously for adiabatic release from a storage tank is applied here to non-adiabatic blowdown of a tank in a fire. Unsteady heat transfer equation is used to calculate heat conduction through the tank wall. It includes the decomposition of the wall material due to high heat flux. The convective heat transfer between tank wall and hydrogen is modelled through the dimensionless Nusselt number correlations. The model is validated against two types of experiments i.e. realistic (non-adiabatic) blowdown of high-pressure storage tank and failure of a tank without TPRD in a fire. The model is confirmed to be time efficient for computations and accurately predicts the dynamic pressure and temperature of the gas inside the tank temperature profile within the tank wall time to tank rupture in a fire and the blowdown time.

During the exemption application process the original report was evaluated as part of a regulatory review and responses to questions submitted for further consideration. These have been addressed in this revised version (revision 1) in the form of an addendum. The addendum includes the question raised its number and the response to it. The area of the main body of the report to which each question and response refers is indicated by square brackets and the addendum number e.g. [A1].<br/>Through analysis of the literature and results of the practical testing the susceptibility of materials present in the Winlaton trial site to hydrogen degradation has been assessed with consideration of the Winlaton operating conditions (up to 20% H2 at total blend pressures of 20 mbar – 2 bar). The aim of this report has been to determine whether there are any components which have been identified at the Winlaton trial site which could have a significantly increased risk of failure due to their exposure to hydrogen during the one year trial. Where possible direct supporting data has been used to make assessments on the likelihood of failure; in other cases the assessment was aided by collaborative expert opinion in the fields of mechanical engineering materials science and the domestic gas industry.<br/>Click on the supplements tab to view the other documents from this report

Preliminary research suggests domestic carbon monoxide detectors with an electrochemical sensor are approximately 10 -20% sensitive to hydrogen atmospheres in their factory configuration. That is the display on a carbon monoxide detector would give a carbon monoxide reading of approximately 10-20% of the concentration of hydrogen it is exposed to. Current British standards require detectors to sound an alarm within three minutes when subjected to a continuous concentration of ≥ 300 ppm CO. This would equate to a concentration of 1500-3000 ppm hydrogen in air or approximately 3.75 – 7% %LEL. The current evacuation criteria for a natural gas leak in a domestic property is 20 %LEL indicating that standard carbon monoxide detectors could be used as cheap and reliable early warning systems for hydrogen leaks. Given the wide use of carbon monoxide detectors and the affordability of the devices the use of carbon monoxide detectors for hydrogen detection is of particular interest as the UK drives towards energy decarbonisation. Experiments to determine the exact sensitivity of a range of the most common domestic carbon monoxide detectors have been completed by DNV Spadeadam Research & Testing. Determining the effects of repeated exposure to varying concentrations of hydrogen in air on the sensitivity of electrochemical sensors allows recommendations to be made on their adoption as hydrogen detectors. Changing the catalysts used within the electrochemical cell would improve the sensitivity to hydrogen however simply calibrating the sensor to report a concentration of hydrogen rather than carbon monoxide would represent no additional costs to manufacturers. Having determined the suitability of such sensors at an early stage; the technology can then be linked with other technological developments required for the change to hydrogen for domestic heating (e.g. change in metering equipment and appliances). This report finds that from five simple and widely available carbon monoxide detectors the lowest sensitivity to hydrogen measured at the concentration required to sound an alarm within three minutes was approximately 10%. It was also discovered that as the hydrogen concentration was increased over the range tested the sensitivity to hydrogen also increased. It is proposed that coupling these devices with other elements of the domestic gas system would allow actions such as remote meter isolation or automatic warning signals sent to response services would provide a reliable and inherently safe system for protecting occupants as gas networks transition to net-zero greenhouse gas emissions. In this respect it is noted that wireless linking of smoke and heat detectors for domestic application is already widely available in low-cost devices. This could be extended to CO detectors adapted for hydrogen use.

Hydrogen Mobility Europe (H2ME 2015–2022) is the largest European Fuel Cells and Hydrogen Joint Undertaking (EU FCH JU)-funded hydrogen light vehicle and infrastructure demonstration. Up until April 2017 the 40 Daimler passenger car fuel cell electric vehicles (FCEVs) and 62 Symbio Fuel Cell-Range Extended Electric Vans (FC-REEV)-vans deployed by the project drove 625300 km and consumed a total of 7900 kg of hydrogen with no safety incidents. During its first year of operation (to April 2017) the NEL Hydrogen Fueling HRS (hydrogen refuelling station) in Kolding Denmark dispensed 900 kg of hydrogen and demonstrated excellent reliability (98.2% availability) with no safety incidents. The average hydrogen refuelling time for passenger cars is comparable to that for conventional vehicles (2–3 min).

Hydrogen has been hailed as a promising energy carrier for decades. But compared to the thriving success of hybrid and plug-in electric cars the prospects for cars powered by hydrogen fuel cells have recently diminished mostly due to challenges in bringing down the costs of fuel cells and developing a broad network of fuelling stations.<br/>Beginning in March 2020 three major auto manufacturers—Daimler AG] Volkswagen and General Motors (GM)]—followed the April 2019 move by Honda to back out of the hydrogen-powered passenger car market. Instead these companies and others are looking to develop the technology as an emission-free solution to power heavy commercial and military vehicles with refuelling taking place at centralized locations.