Publications

Industrial and public interest in hydrogen technologies has risen strongly recently as hydrogen is the ideal means for medium to long term energy storage transport and usage in combination with renewable and green energy supply. In a future energy system the production storage and usage of green hydrogen is a key technology. Hydrogen is and will in future be even more used for industrial production processes as a reduction agent or for the production of synthetic hydrocarbons especially in the chemical industry and in refineries. Under certain conditions material based systems for hydrogen storage and compression offer advantages over the classical systems based on gaseous or liquid hydrogen. This includes in particular lower maintenance costs higher reliability and safety. Hydrogen storage is possible at pressures and temperatures much closer to ambient conditions. Hydrogen compression is possible without any moving parts and only by using waste heat. In this paper we summarize the newest developments of hydrogen carriers for storage and compression and in addition give an overview of the different research activities in this field.

Hydrogen is an emerging energy vector many components of which are mature technologies. Current hydrogen technology is already able to provide advantages over other energy vectors and many of its challenges are being actively addressed by research and development.<br/><br/>Hydrogen can be derived stored and converted through various processes each of which represents different levels of carbon intensity efficiency and end use functionality. Our latest five minute guide looks at this energy vector in brief including public perception transportation and storage as well as using hydrogen as a solution.

Expectations for energy storage are high but large-scale underground hydrogen storage in porous media (UHSP) remains largely untested. This article identifies and discusses the scientific challenges of hydrogen storage in porous media for safe and efficient large-scale energy storage to enable a global hydrogen economy. To facilitate hydrogen supply on the scales required for a zero-carbon future it must be stored in porous geological formations such as saline aquifers and depleted hydrocarbon reservoirs. Large-scale UHSP offers the much-needed capacity to balance inter-seasonal discrepancies between demand and supply decouple energy generation from demand and decarbonise heating and transport supporting decarbonisation of the entire energy system. Despite the vast opportunity provided by UHSP the maturity is considered low and as such UHSP is associated with several uncertainties and challenges. Here the safety and economic impacts triggered by poorly understood key processes are identified such as the formation of corrosive hydrogen sulfide gas hydrogen loss due to the activity of microbes or permeability changes due to geochemical interactions impacting on the predictability of hydrogen flow through porous media. The wide range of scientific challenges facing UHSP are outlined to improve procedures and workflows for the hydrogen storage cycle from site selection to storage site operation. Multidisciplinary research including reservoir engineering chemistry geology and microbiology more complex than required for CH₄ or CO₂ storage is required in order to implement the safe efficient and much needed large-scale commercial deployment of UHSP.

This study presents an integrated techno-environmental assessment of hydrogen production from natural gas and biomethane combined with CO₂ capture and storage (CCS). We have included steam methane reforming (SMR) and autothermal reforming (ATR) for syngas production. CO₂ is captured from the syngas with a novel vacuum pressure swing adsorption (VPSA) process that combines hydrogen purification and CO₂ separation in one cycle. As comparison we have included cases with conventional amine-based technology. We have extended standard attributional Life Cycle Assessment (LCA) following ISO standards with a detailed carbon balance of the biogas production process (via digestion) and its by-products. The results show that the life-cycle greenhouse gas (GHG) performance of the VPSA and amine-based CO₂ capture technologies is very similar as a result of comparable energy consumption. The configuration with the highest plant-wide CO₂ capture rate (almost 100% of produced CO₂ captured) is autothermal reforming with a two-stage water-gas shift and VPSA CO₂ capture – because the latter has an inherently high CO₂ capture rate of 98% or more for the investigated syngas. Depending on the configuration the addition of CCS to natural gas reforming-based hydrogen production reduces its life-cycle Global Warming Potential by 45–85 percent while the other environmental life-cycle impacts slightly increase. This brings natural gas-based hydrogen on par with renewable electricity-based hydrogen regarding impacts on climate change. When biomethane is used instead of natural gas our study shows potential for net negative greenhouse gas emissions i.e. the net removal of CO₂ over the life cycle of biowaste-based hydrogen production. In the special case where the biogas digestate is used as agricultural fertiliser and where a substantial amount of the carbon in the digestate remains in the soil the biowaste-based hydrogen reaches net-negative life cycle greenhouse gas emissions even without the application of CCS. Addition of CCS to biomethane-based hydrogen production leads to net-negative emissions in all investigated cases.

Only emissions-free vehicles which include battery electric (BEVs) and hydrogen fuel cell trucks (FCEVs) can provide for a credible long-term pathway towards the full decarbonisation of the road freight sector. This document lays out the methodology and assumptions which were used to calculate the total cost of ownership (TCO) of the two vehicle technologies for regional delivery and long-haul truck applications. It also discusses other criteria such as refuelling and recharging times as well as potential payload losses.

Link to Document Download on Transport & Environment website

Global warming and melting of the ice on both poles of the Earth is caused by the greenhouse effect which is the result of CO₂ production. This gas is considered as the main gas causing the greenhouse effect although not the only one. To reduce the total amount of CO2 emitted to the atmosphere mankind looks for an alternative fuel with no carbon present in its molekules. Hydrogen is such a fuel although emissions are produced also during the fuel production process. To compare hydrogen fuel with fossil fuels more aspects have to be considered.

Direct Numerical Simulation (DNS) data obtained by Dave and Chaudhuri (2020) from a lean complex-chemistry hydrogen-air flame associated with the thin-reaction-zone regime of premixed turbulent burning are analyzed to perform a priori assessment of predictive capabilities of the flamelet approach for evaluating mean species concentrations. For this purpose dependencies of mole fractions and rates of production of various species on a combustion progress variable c obtained from the laminar flame are averaged adopting either the actual Probability Density Function (PDF) P (c)  extracted from the DNS data or a common presumed β-function PDF. On the one hand the results quantitatively validate the flamelet approach for the mean mole fractions of all species including radicals but only if the actual PDF P (c) is adopted. The use of the β-function PDF yields substantially worse results for the radicals’ concentrations. These findings put modeling the PDF P (c) on the forefront of the research agenda. On the other hand the mean rate of product creation and turbulent burning velocity are poorly predicted even adopting the actual PDF. These results imply that in order to evaluate the mean species concentrations the flamelet approach could be coupled with another model that predicts the mean rate and turbulent burning velocity better. Accordingly the flamelet approach could be implemented as post-processing of numerical data yielded by that model. Based on the aforementioned findings and implications a new approach to building a presumed PDF is developed. The key features of the approach consist in (i) adopting a re-normalized flamelet PDF for intermediate values of c and (ii) directly using the mean rate of product creation to calibrate the presumed PDF. Capabilities of the newly developed PDF for predicting mean species concentrations are quantitively validated for all species including radicals.

As the global electricity systems are shaped by decentralisation digitalisation and decarbonisation the World Energy Council’s Innovation Insights Briefs explore the new frontiers in energy transitions and the challenges of keeping pace with fast moving developments. We use leadership interviews to map the state of play and case studies across the whole energy landscape and build a broader and deeper picture of new developments within and beyond the new energy technology value chain and business ecosystem.<br/><br/>With major decarbonisation efforts and the scaling up of renewable power generation the widespread adoption of energy storage continues to be described as the key game changer for electricity systems. Affordable storage systems are a critical missing link between intermittent renewable power and a 24/7 reliability net-zero carbon scenario. Beyond solving this salient challenge energy storage is being increasingly considered to meet other needs such as relieving congestion or smoothing out the variations in power that occur independently of renewable-energy generation. However whilst there is plenty of visionary thinking recent progress has focused on short-duration and battery-based energy storage for efficiency gains and ancillary services; there is limited progress in developing daily weekly and even seasonal cost-effective solutions which are indispensable for a global reliance on intermittent renewable energy sources.

The use of clean hydrogen is likely to form a key part of a net-zero emissions future and has the potential to replace natural gas for end use heating. As part of BDR Thermea Group Baxi Heating UK are at the forefront of hydrogen boiler development. Working with the Hy4Heat programme hydrogen fuelled boilers have been produced for inclusion in trial sites across the UK. This presentation will explore progress to date together with the hydrogen-ready boiler concept.

Alloying and structural modification are two effective ways to enhance the hydrogen storage kinetics and decrease the thermal stability of Mg and Mg-based alloys. In order to enhance the characteristics of Mg₂Ni-type alloys Cu and La were added to an Mg₂Ni-type alloy and the sample alloys (Mg₂₄Ni₁₀Cu₂)_100−xLa_x (x = 0 5 10 15 20) were prepared by melt spinning. The influences of La content and spinning rate on the gaseous and electrochemical hydrogen storage properties of the sample alloys were explored in detail. The structural identification carried out by XRD and TEM indicates that the main phase of the alloys is Mg₂Ni and the addition of La results in the formation of the secondary phases LaMg₃ and La₂Mg₁₇. The as-spun alloys have amorphous and nanocrystalline structures and the addition of La promotes glass formation. The electrochemical properties examined by an automatic galvanostatic system show that the samples possess a good activation capability and achieve their maximal discharge capacities within three cycles. The discharge potential characteristics were vastly ameliorated by melt spinning and La addition. The discharge capacities of the samples achieve their maximal values as the La content changes and the discharge capacities always increase with increasing spinning rate. The addition of La leads to a decline in hydrogen absorption capacity but it can effectively enhance the rate of hydrogen absorption. The addition of La and melt spinning significantly increase the hydrogen desorption rate due to the reduced activation energy.

From a permeability and selectivity perspective supported thin-film Pd–Ag membranes are the best candidates for high-purity hydrogen recovery for methane-hydrogen mixtures from the natural gas grid. However the high hydrogen flux also results in induced bulk-to-membrane mass transfer limitations (concentration polarization) especially when working at low hydrogen concentration and high pressure which further reduces the hydrogen permeance in the presence of mixtures. Additionally Pd is a precious metal and its price is lately increasing dramatically. The use of inexpensive CMSM could become a promising alternative. In this manuscript a detailed comparison between these two membrane technologies operating under the same working pressure and mixtures is presented.<br/>First the permeation properties of CMSM and Pd–Ag membranes are compared in terms of permeance and purity and subsequently making use of this experimental investigation an economic evaluation including capital and variable costs has been performed for a separation system to recover 25 kg/day of hydrogen from a methane-hydrogen mixture. To widen the perspective also a sensitivity analysis by changing the pressure difference membrane lifetime membrane support cost and cost of Pd/Ag membrane recovery has been considered. The results show that at high pressure the use of CMSM is to more economic than the Pd-based membranes at the same recovery and similar purity.

This report shows that low-carbon hydrogen supply at scale is economically and environmentally feasible and will have significant societal benefits if the right localised approach and best-practices for production are used. The report also demonstrates that there is not one single hydrogen production pathway to achieve low lifecycle greenhouse gas (GHG) emissions but rather the need for a fact-based approach that leverages regional resources and includes a combination of different production pathways. This will achieve both emission and cost reductions ultimately helping to decarbonize the energy system and limit global warming.

In 2020 more than 15 countries launched major hydrogen plans and policies and industry players announced new projects of more than 35GW until 2030. As this hydrogen momentum accelerates it is increasingly clear that decision makers must put the focus on decarbonization to ensure hydrogen can fulfil its potential as a key solution in the global clean energy transition making a significant contribution to net zero emissions. To support this effort the two-part Hydrogen Council report provides new data based on an assessment of the GHG emissions generated through different hydrogen supply pathways and the lifecycle GHG emissions for different hydrogen applications (see report part 1 – A Life-cycle Assessment). In addition the report explores 3 hypothetical hydrogen supply scenarios to measure the feasibility and impact of deploying renewable and low-carbon hydrogen at scale (report part 2 – Potential Supply Scenarios).

The report outlines that there are many ways of producing hydrogen and although GHG emissions vary widely very high CO2 savings can be achieved across a broad range of different hydrogen production pathways and end-uses. For example while “green” hydrogen produced through water electrolysis with renewable power achieves the lowest emissions “blue” hydrogen produced from natural gas with high CO2 capture rate and storage can also achieve low emissions if best technologies are used and best practices are followed. Across eight illustrative pathways explored in the report analysis shows that if hydrogen is used significant GHG emission reductions can be made: as much as 60-90% or more compared to conventional fossil alternatives. The study also looked into the gross water demand of hydrogen supply pathways. Water electrolysis has a very low specific water demand of 9 kg per kg of hydrogen compared to cooling of thermal power plants (hundreds of kg/kg) or biomass cultivation (hundreds to thousands of kg/kg).

Furthermore low-carbon hydrogen supply at scale is fully achievable. Having investigated two hypothetical boundary scenarios (a “green-only” and a “blue-only” scenario) to assess the feasibility and impact of decarbonized hydrogen supply the report found that both scenarios are feasible: they are not limited by the world’s renewables potential or carbon sequestration (CCS) capacities and they do not exceed the speed at which industry can scale. In the Hydrogen Council’s “Scaling up” study a demand of 21800 TWh hydrogen has been identified for the year 2050. To achieve this a compound annual growth rate of 30-35% would be needed for electrolysers and CCS. This deployment rate is in line with the growth of the offshore wind and solar PV industry over the last decade.

Hydrogen Council data released in January 2020 showed that a wide range of hydrogen applications can become competitive by 2030 driven also by falling costs of renewable and low-carbon hydrogen[1]. The new study indicates that a combination of “green” and “blue” production pathways would lead to hydrogen cost reductions relative to either boundary scenario. By making use of the near-term cost advantage of “blue” while also scaling up “green” hydrogen as the most cost-efficient option in many regions in the medium and long-term the combined approach lowers average hydrogen costs between now and 2050 relative to either boundary scenario.

Part 1 – A Life-cycle Assessment

• The life-cycle assessment (LCA) analysis in this study addresses every aspect of the supply chain from primary energy extraction to end use. Eight primary-energy-to-hydrogen value chains have been selected for illustrative purposes.
• Across the hydrogen pathways and applications depicted very high to high GHG emission reduction can be demonstrated using green (solar wind) and blue hydrogen.
• In the LCA study renewables + electrolysis shows strongest GHG reduction of the different hydrogen supply pathways assessed in this study with a best-case blue hydrogen pathway also coming into the same order of magnitude.

Part 2 – Potential Supply Scenarios

• Currently the vast majority of hydrogen is produced by fossil pathways. To achieve a ten-fold build-out of hydrogen supply by 2050 as envisaged by the Hydrogen Council in its ‘Scaling Up’ report (2017) the existing use of hydrogen – and all its many potential new roles – need to be met by decarbonized sources.
• Three hypothetical supply scenarios with decarbonized hydrogen sources are considered in the study: 1) a “green-only” renewables-based world; 2) a “blue-only” world relying on carbon sequestration; and 3) a combined scenario that uses a region-specific combination of green and blue hydrogen based on the expected regional cost development of each source.
• The study finds that a decarbonized hydrogen supply is possible regardless of the production pathway: while both the green and blue boundary scenario would be highly ambitious regarding the required speed of scale-up they do not exceed the world’s resources on either renewable energy or carbon sequestration capabilities.
• A combination of production pathways would result in the least-cost global supply over the entire period of scale-up. It does so by making best use of the near-term cost advantage of “blue” in some regions while simultaneously achieving a scale-up in electrolysis.
• In reality the decarbonized supply scenario will combine a range of different renewable and low-carbon hydrogen production pathways that are optimally suited to local conditions political and societal preferences and regulations as well as industrial and cost developments for different technologies.

You can download the full reports from the Hydrogen Council website

Hydrogen Council Report- Decarbonization Pathways Part 1: Life Cycle Assessment here

Hydrogen Council Report-Decarbonization Pathways Part 2: Supply Scenarios here

An executive summary of the whole project can be found here

As countries around the world rally behind net zero targets hydrogen is increasingly seen as a missing piece of the energy transformation puzzle to decarbonise harder-to-abate sectors. The possible pathway on which hydrogen might evolve still involves many uncertainties. With the growing momentum to establish a global hydrogen market comes the need for a deeper understanding of its broader effects including geopolitical aspects. IRENA has carried out an in-depth analysis of the geopolitics of hydrogen as part of the work of the Collaborative Framework on the Geopolitics of Energy Transformation (CF-GET). The report builds on IRENA’s substantial body of work in hydrogen and benefits from a wide range of expert input in the fields of energy and geopolitics.

This report considers whether and how hydrogen may disrupt future energy systems reflecting on many of the key themes discussed in the Global Commission’s report A New World – The Geopolitics of the Energy Transformation. The analysis offers insights into how countries and stakeholders can navigate the uncertainties and shape the development of hydrogen markets and outlines policy considerations to help mitigate the geopolitical risks and capitalise on opportunities. Some of the key findings of the report include:

• Hydrogen is part of a much bigger energy transition picture and its development and deployment strategies should not be considered in isolation.
• Setting the right priorities for hydrogen use will be essential for its rapid scale-up and long-term contribution to decarbonisation efforts.
• The 2020s could become the era of a big race for technology leadership as costs are likely to fall sharply with learning and scaling-up of needed infrastructure. Equipment manufacturing offers an opportunity to capture value in the coming years and decades.
• Hydrogen trade and investment flows will spawn new patterns of interdependence and bring shifts in bilateral relations.
• Countries with an abundance of low-cost renewable power could become producers of green hydrogen with commensurate geoeconomic and geopolitical consequences.
• Hydrogen could be an attractive avenue for fossil fuel exporters to help diversify their economies and develop new export industries.
• Supporting the advancement of renewable energy and green hydrogen in developing countries is critical for decarbonising the energy system and can contribute to global equity and stability.
• International co-operation will be necessary to devise a transparent hydrogen market with coherent standards and norms that contribute to climate change efforts meaningfully.

The effect of different cathodic potentials applied to the X70 pipeline steel immersed in acidified and aerated synthetic soil solution under stress using a slow strain rate test (SSRT) and electrochemical impedance spectroscopy (EIS) was studied. According to SSRT results and the fracture surface analysis by scanning electron microscopy (SEM) the steel susceptibility to stress corrosion cracking (SCC) increased as the cathodic polarization increased (Ecp). This behavior is attributed to the anodic dissolution at the tip of the crack and the increment of the cathodic reaction (hydrogen evolution) producing hydrogen embrittlement. Nevertheless when the Ecp was subjected to the maximum cathodic potential applied (−970 mV) the susceptibility decreased; this behavior is attributed to the fact that the anodic dissolution was suppressed and the process of the SCC was dominated only by hydrogen embrittlement (HE). The EIS results showed that the cathodic process was influenced by the mass transport (hydrogen diffusion) due to the steel undergoing so many changes in the metallic surface as a result of the applied strain that it generated active sites at the surface.

For liquid hydrogen (LH₂) to become an energy carrier in energy commodity markets at scales comparable to for instance LNG liquefier capacities must be scaled up several orders of magnitude. While state-of-the-art liquefiers can provide specific power requirements down to 10 kWh/kg a long-term target for scaled-up liquefier trains is 6 kWh/kg. High capacity will shift the cost weighting more towards operational expenditures which motivates for measures to improve the efficiency. Detailed exergy analysis is the best means for gaining a clear understanding of all losses occurring in the liquefaction process. This work analyses in detail a hydrogen liquefier that is likely to be realisable without intermediate demonstration phases and all irreversibilities are decomposed to the component level. The overall aim is to identify the most promising routes for improving the process. The overall power requirement is found to be 7.09 kWh/kg with stand-alone exergy efficiencies of the mixed-refrigerant pre-cooling cycle and the cryogenic hydrogen Claude cycle of 42.5% and 38.4% respectively. About 90% of the irreversibilities are attributed to the Claude cycle while the remainder is caused by pre-cooling to 114 K. For a component group subdivision the main contributions to irreversibilities are hydrogen compression and intercooling (39%) cryogenic heat exchangers (21%) hydrogen turbine brakes (15%) and hydrogen turbines (13%). Efficiency improvement measures become increasingly attractive with scale in general and several options exist. An effective modification is to recover shaft power from the cryogenic turbines. 80% shaft-to-shaft power recovery will reduce the power requirement to 6.57 kWh/kg. Another potent modification is to replace the single mixed refrigerant pre-cooling cycle with a more advanced mixed-refrigerant cascade cycle. For substantial scaling-up in the long term promising solutions can be cryogenic refrigeration cycles with refrigerant mixtures of helium/neon/hydrogen enabling the use of efficient and well scalable centrifugal compressors.

Chemical looping water splitting or chemical looping hydrogen is a very promising technology for the production of hydrogen. In recent years extensive research has enabled remarkable leaps towards a successful integration of the chemical looping technology into a future hydrogen infrastructure. Progress has been reported with iron based oxygen carriers for stable hydrogen production capacity over consecutive cycles without significant signs of degradation. The high stability improvements were achieved by adding alien metal oxides or by integrating the active component into a mineral structure which offers excellent resistance towards thermal stress. Prototype systems from small μ-systems up to 50 kW have been operated with promising results. The chemical looping water splitting process was broadened in terms of its application area and utilization of feedstocks using a variety of renewable and fossil resources. The three-reactor system was clearly advantageous due to its flexibility heat integration capabilities and possibility to produce separate pure streams of hydrogen CO₂ and N₂. However two-reactor and single fixed-bed reactor systems were successfully operated as well. This review aims to survey the recently presented literature in detail and systematically summarize the gathered data.

There is uncertainty over how heating might practically be decarbonised in the future. This briefing provides some clarity about the possible pathways forward focusing on the next 5-10 years.<br/>Meeting the UK government’s net zero emissions goal for 2050 will only be possible by complete decarbonisation of the building stock (both existing and new).  There is uncertainty over the extent to which heating might practically be decarbonised in the future and what the optimal technologies may be. This paper provides some clarity about the pathways forward focusing on the next 5-10 years.

Hydrogen interaction with metal atoms is of prime focus for many energy related applications like hydrogen storage hydrogen evolution using catalysis etc. Although hydrogen binding with many main group alkaline and transition metals is quite well understood its binding properties with lanthanides are not well reported. In this article by density functional theory studies we show how a rare earth metal cerium binds with hydrogen when decorated over a heteropolar 2D material hexagonal boron nitride. Each cerium adatom is found to bind eight hydrogen molecules which is a much higher number than has been reported for transition metal atoms. However the highest binding energy occurs at four hydrogen molecules. This anomaly therefore is investigated in the present article using first-principles calculations. The number density of hydrogen molecules adsorbed over the cerium adatom is explained by investigating the electronic charge volume interactions owing to a unique geometrical arrangement of the guest hydrogen molecules. The importance of geometrical encapsulation in enhancing electronic interactions is explained.

Chemical looping combustion (CLC) is a promising method for power production with integrated CO₂ capture with almost no direct energy penalty. When integrated into a natural gas combined cycle (NGCC) plant however CLC imposes a large indirect energy penalty because the maximum achievable reactor temperature is far below the firing temperature of state-of-the-art gas turbines. This study presents a techno-economic assessment of a CLC plant that circumvents this limitation via an added combustor after the CLC reactors. Without the added combustor the energy penalty amounts to 11.4%-points causing a high CO₂ avoidance cost of $117.3/ton which is more expensive than a conventional NGCC plant with post-combustion capture ($93.8/ton) with an energy penalty of 8.1%-points. This conventional CLC plant would also require a custom gas turbine. With an added combustor fired by natural gas a standard gas turbine can be deployed and CO2 avoidance costs are reduced to $60.3/ton mainly due to a reduction in the energy penalty to only 1.4%-points. However due to the added natural gas combustion after the CLC reactor CO₂ avoidance is only 52.4%. Achieving high CO₂ avoidance requires firing with clean hydrogen instead increasing the CO₂ avoidance cost to $96.3/ton when a hydrogen cost of $15.5/GJ is assumed. Advanced heat integration could reduce the CO₂ avoidance cost to $90.3/ton by lowering the energy penalty to only 0.6%-points. An attractive alternative is therefore to construct the plant for added firing with natural gas and retrofit the added combustor for hydrogen firing when CO₂ prices reach very high levels.

Hydrogen absorption into steel during atmospheric corrosion has been of a strong concern during last decades. It is technically important to investigate if hydrogen absorbed under atmospheric exposure conditions can significantly affect mechanical properties of steels. The present work studies changes of mechanical properties of dual phase (DP) advanced high strength steel specimens with sodium chloride deposits during corrosion in humid air using Slow Strain Rate Test (SSRT). Additional annealed specimens were used as reference in order to separate the possible effect of absorbed hydrogen from that of corrosion deterioration. Hydrogen entry was monitored in parallel experiments using hydrogen electric resistance sensor (HERS) and thermal desorption mass spectrometry (TDMS). SSRT results showed a drop in elongation and tensile strength by 42% and 6% respectively in 27 days of atmospheric exposure. However this decrease cannot be attributed to the effect of absorbed hydrogen despite the increase in hydrogen content with time of exposure. Cross-cut analysis revealed considerable pitting which was suggested to be the main reason for the degradation of mechanical properties

Replacing natural gas with hydrogen in an everyday setting – piping hydrogen to homes and businesses through the existing gas network – is a new and untested proposition. At the same time piloting this proposition is an essential ingredient to a well-managed low carbon transition.<br/>The Department of Business Energy and Industrial Strategy (BEIS) has commissioned CAG Consultants to undertake a literature review and conduct a set of four focus groups to inform the development of work to assess issues associated with setting up a hypothetical community hydrogen trial. This report sets out the findings from the research and presents reflections on the implications of the findings for any future community hydrogen heating trials.<br/>The literature review was a short focused review aimed at identifying evidence relevant to members of the public being asked to take part in a hypothetical community trial. Based primarily on Quick Scoping Review principles the review involved the analysis of evidence from 26 items of literature. The four focus groups were held in-person in two city locations Manchester and Birmingham in November 2019. They involved consumers who either owned or rented houses (i.e. not flats) connected to the gas grid. Two of the focus groups involved owner-occupiers one was with private landlords and the other was with a mixture of tenants (private social and student).<br/>This report was produced in October 2019 and published in December 2020. 

This paper aims to expand current thinking about the future of energy and water utility provision by presenting a radical idea: it proposes a combined delivery system for household energy and water utilities which is inspired by an analogy with the human body. It envisions a multi-functional infrastructure for cities of the future modelled on the human circulatory system. Red blood cells play a crucial role as energy carriers in biological energy distribution; they are suspended in the blood and distributed around the body to fuel the living cells. So why not use an analogous system e an urban circulatory system or “city blood” e to deliver energy and water simultaneously via one dedicated pipeline system? This paper focuses on analysing the scientific technological and economic feasibilities and hurdles which would need to be overcome in order to achieve this idea.<br/>We present a rationale for the requirement of an improved household utility delivery infrastructure and discuss the inspirational analogy; the technological components required to realise the vignette are also discussed. We identify the most significant advance requirement for the proposal to succeed: the utilisation of solid or liquid substrate materials delivered through water pipelines; their benefits and risks are discussed.

This study outlines a pathway for commercialisation of stationary fuel cells in distributed generation across Europe. It has been sponsored by the Fuel Cells and Hydrogen Joint Undertaking (FCH JU) a public-private partnership between the European Commission the fuel cell and hydrogen industry and a number of research bodies and associations. The FCH JU supports research technology development and demonstration activities in the field of fuel cell and hydrogen technologies in Europe. The study explores how stationary fuel cells can benefit users how they can be brought to the market what hurdles still exist and how their diffusion may foster Europe's transition into a new energy age.

Flame acceleration (FA) and explosion of hydrogen/air mixtures remain key issues for severe accident management in nuclear power plants. Empirical criteria were developed in the early 2000s by Dorofeev and colleagues providing effective tools to discern possible FA or DDT (Deflagration-to-Detonation Transition) scenarios. A large experimental database composed mainly of middle-scale experiments in obstacle-laden ducts at atmospheric pressure condition has been used to validate these criteria. However during a severe accident the high release rate of steam and non-condensable gases into the containment can result in pressure increase up to 5 bar abs. In the present work the influence of the unburnt gas initial pressure on flame propagation mechanisms was experimentally investigated. Premixed hydrogen/air mixtures with hydrogen concentration close to 11% and 15% were considered. From the literature we know that these flames are supposed to accelerate up to Chapman-Jouguet deflagration velocity in long obstacle-laden tubes at initial atmospheric conditions. Varying the pressure in the fresh gas in the range 0.6–4 bar no effects on the flame acceleration phase were observed. However as the initial pressure was increased we observed a decrease in the flame velocity close to the end of the tube. The pressure increase due to the combustion reaction was found to be proportional to the initial pressure according to adiabatic isochoric complete combustion.

Thermal power plants face substantial challenges to remain competitive in energy systems with high shares of variable renewables especially inflexible integrated gasification combined cycles (IGCC). This study addresses this challenge through the integration of Gas Switching Combustion (GSC) and Membrane Assisted Water Gas Shift (MAWGS) reactors in an IGCC plant for flexible electricity and/or H₂ production with inherent CO₂ capture. When electricity prices are high H₂ from the MAWGS reactor is used for added firing after the GSC reactors to reach the high turbine inlet temperature of the H-class gas turbine. In periods of low electricity prices the turbine operates at 10% of its rated power to satisfy the internal electricity demand while a large portion of the syngas heating value is extracted as H₂ in the MAWGS reactor and sold to the market. This product flexibility allows the inflexible process units such as gasification gas treating air separation unit and CO2 compression transport and storage to operate continuously while the plant supplies variable power output. Two configurations of the GSC-MAWGS plant are presented. The base configuration achieves 47.2% electric efficiency and 56.6% equivalent hydrogen production efficiency with 94.8–95.6% CO₂ capture. An advanced scheme using the GSC reduction gases for coal-water slurry preheating and pre-gasification reached an electric efficiency of 50.3% hydrogen efficiency of 62.4% and CO₂ capture ratio of 98.1–99.5%. The efficiency is 8.4%-points higher than the pre-combustion CO₂ capture benchmark and only 1.9%-points below the unabated IGCC benchmark.