United Kingdom

Hydrogen is widely recognized as an attractive energy carrier due to its low-level air pollution and its high mass-related energy density. However its wide flammability range and high burning velocity present a potentially significant hazard. A significant fraction of hydrogen is stored and transported as a cryogenic liquid (liquid hydrogen or LH2) as it requires much less volume compared to gaseous hydrogen. In order to exist as a liquid H2 must be cooled to a very low temperature 20.28 K. LH2 is a common liquid fuel for rocket applications. It can also be used as the fuel storage in an internal combustion engine or fuel cell for transport applications. Models for handling liquid releases both two-phase flashing jets and pool spills have been developed in the CFD-model FLACS. The very low normal boiling point of hydrogen (20 K) leads to particular challenges as this is significantly lower than the boiling points of oxygen (90 K) and nitrogen (77 K). Therefore a release of LH2 in the atmosphere may induce partial condensation or even freezing of the oxygen and nitrogen present in the air. A pool model within the CFD software FLACS is used to compute the spreading and vaporization of the liquid hydrogen depositing on the ground where the partial condensation or freezing of the oxygen and nitrogen is also taken into account. In our computations of two-phase jets the dispersed and continuous phases are assumed to be in thermodynamic and kinematic equilibrium. Simulations with the new models are compared against selected experiments performed at the Health and Safety Laboratory (HSL).

The HyDeploy project is the UK’s first practical project to demonstrate that hydrogen can be safely blended into the natural-gas distribution system without requiring changes to appliances and the associated disruption. The project is funded under Ofgem’s Network Innovation Competition and is a collaboration between Cadent Gas Northern Gas Networks Progressive Energy Ltd Keele University (Keele) Health & Safety Laboratory and ITM Power. Cadent and Northern Gas Networks are the Gas Distribution Network sponsors of the project. Keele University is the host site providing the gas-distribution network which will receive the hydrogen blend. Keele University is the largest campus university in the UK. Health & Safety Laboratory provides the scientific laboratories and experimental expertise. ITM Power provides the electrolyser that produces the hydrogen. Progressive Energy Ltd is the project developer and project manager. HyDeploy is structured into three distinct phases. The first is an extensive technical programme to establish the necessary detailed evidence base in support of an application to the Health & Safety Executive for Exemption to Schedule 3 of the Gas Safety (Management) Regulations (GS(M)R) to permit the injection of hydrogen at 20 mol%. This is required to allow hydrogen to be blended into a natural-gas supply above the current British limit of 0.1 mol%.



The second phase comprises the construction of the electrolyser and grid entry unit along with the necessary piping and valves to allow hydrogen to be mixed and injected into the Keele University gas-distribution network and to ensure all necessary training of operatives is conducted before injection. The third phase is the trial itself which is due to start in the summer of 2019 and last around 10 months. The trial phase also provides an opportunity to undertake further experimental activities related to the operational network to support the pathway to full deployment of blended gas. The outcome of HyDeploy is principally developing the initial evidence base that hydrogen can be blended into a UK operational natural-gas network without disruption to customers and without prejudicing the safety of end users. If deployed at scale hydrogen blending at 20 mol% would unlock 29 TWh pa of decarbonized heat and provide a route map for deeper savings. The equivalent carbon savings of a national roll-out of a 20-mol% hydrogen blend would be to remove 2.5 million cars from the road.



HyDeploy is a seminal UK project for the decarbonization of the gas grid via hydrogen deployment and will provide the first stepping stone for setting technical operational and regulatory precedents of the hydrogen vector.

This report responds to a request from the Governments of the UK Wales and Scotland asking the Committee to reassess the UK’s long-term emissions targets. Our new emissions scenarios draw on ten new research projects three expert advisory groups and reviews of the work of the IPCC and others.<br/>The conclusions are supported by detailed analysis published in the Net Zero Technical Report that has been carried out for each sector of the economy plus consideration of F-gas emissions and greenhouse gas removals.

This spreadsheet contains data for two future UK scenarios: a "baseline" (i.e. no climate action after 2008 the start of the carbon budget system) and the "central" scenario underpinning the CCC's advice on the fifth carbon budget (the limit to domestic emissions during the period 2028-32).<br/>The central scenario is an assessment of the technologies and behaviours that would prepare for the 2050 target cost-effectively while meeting the other criteria in the Climate Change Act (2008) based on central views of technology costs fuel prices carbon prices and feasibility. It is not prescriptive nor is it the only scenario considered for meeting the carbon budgets. For further details on our scenarios and how they were generated see the CCC report Sectoral scenarios for the Fifth Carbon Budget. The scenario was constructed for the CCC's November 2015 report and has not been further updated for example to reflect outturn data for 2015 or changes to Government policy.

This is the second document of a two-part review of the Fourth Carbon Budget which covers 2023 to 2027. The Fourth Carbon Budget agreed by the Government in June 2011 was scheduled to be reviewed in 2014. The first part of the review is available here: The Fourth Carbon Budget Review – part 1: assessment of climate risk and the international response (November 2013).<br/>According to the Climate Change Act 2008 carbon budgets can only be altered if there is a significant change in circumstances upon which the budget was set. Any such change in circumstances must be demonstrated through evidence and analysis.<br/>The Fourth Carbon Budget Review – part 2 considers the impacts of meeting the 2023-2027 budget. The review concludes that the impacts are small and manageable and identifies broader benefits associated with meeting the fourth carbon budget including: improved energy security improved air quality and reduced noise pollution.

This is the eighth annual Progress Report to the Scottish Parliament required by Scottish Ministers under the Climate Change (Scotland) Act 2009. It assesses Scotland’s progress in achieving its legislated targets to reduce greenhouse gas emissions.<br/>Overall greenhouse gas emissions reduced by 3% in 2017 compared to a 10% fall in 2016. The fall was again led by the power sector due in large part to Scotland’s first full year of coal-free electricity generation. Recent performance in other sectors shows only incremental improvement at best and unless emissions reductions are delivered economy-wide Scotland is at risk of missing its new interim target of a 56% reduction in emissions by 2020. Setting a net-zero greenhouse gas emissions target for 2045 represents a step-change in ambition for Scotland. The Scottish Parliament’s 2030 target to reduce emissions by 75% will be extremely challenging to meet. It must be backed up by steps to drive meaningful emissions reductions immediately.<br/>Scotland’s Programme for Government 2019-20 alongside other recent policies sent a clear signal that the Scottish Government is taking its more ambitious targets seriously but there is much more to do.Scotland’s ability to deliver its net-zero target is contingent on action taken in the UK and vice versa.

This study aims to present a philosophical and quantitative perspective of a propulsion system for a large-scale hydrogen-fuelled liquid-hydrogen (LH2) tanker ship. Established methods are used to evaluate the design and performance of an LH2-carrier propulsion system for JAMILA a ship designed with four cylindrical LH2 tanks bearing a total capacity of ~280000 m3 along with cargo and using the boil-off as propulsion and power fuel. Additionally the ship propulsion system is evaluated based on the ship resistance requirements and a hydrogen-fuelled combined-cycle gas turbine is modelled to achieve the dual objectives of high efficiency and zero-carbon footprint. The required inputs primarily involve the off-design and degraded performance of the gas-turbine topping cycle and the proposed power plant operates with a total output power of 50 M.W. The results reveal that the output power allows ship operation at a great speed even with a degraded engine and adverse ambient conditions.

For the UK to meet their national target of net zero emissions as part of the central Paris Agreement target further emphasis needs to be placed on decarbonizing public transport and moving away from personal transport (conventionally fuelled vehicles (CFVs) and electric vehicles (EVs)). Electric buses (EBs) and hydrogen buses (HBs) have the potential to fulfil requirements if powered from low carbon renewable energy sources.

A comparison of carbon dioxide (CO₂) emissions produced from conventionally fuelled buses (CFB) EBs and HBs between 2017 and 2050 under four National Grid electricity scenarios was conducted. In addition emissions per person at different vehicle capacity levels (100% 75% 50% and 25%) were projected for CFBs HBs EBs and personal transport assuming a maximum of 80 passengers per bus and four per personal vehicle.

Results indicated that CFVs produced 30 g CO₂km⁻¹ per person compared to 16.3 g CO₂ km⁻¹ per person by CFBs by 2050. At 100% capacity under the two-degree scenario CFB emissions were 36 times higher than EBs 9 times higher than HBs and 12 times higher than EVs in 2050. Cumulative emissions under all electricity scenarios remained lower for EBs and HBs.

Policy makers need to focus on encouraging a modal shift from personal transport towards sustainable public transport primarily EBs as the lowest level emitting vehicle type. Simple electrification of personal vehicles will not meet the required targets. Simultaneously CFBs need to be replaced with EBs and HBs if the UK is going to meet emission targets.

The Energy Systems Catapult (ESC) explored the role of households in a net-zero emissions society to accompany the CCC’s Net Zero report looking at opportunities and challenges for households to reduce emissions from today’s levels and to support the stretch from an 80% emissions reduction to a net-zero greenhouse gas target. As well as describing a net-zero emissions world for households of different types the ESC looked at average household emissions under different decarbonisation scenarios and the options households can take to contribute to the decarbonisation effort.

This supported the Net Zero Technical report.

The CCC has established a variety of viable scenarios in which UK decarbonisation targets can be met. Each has consequences for the way in which the UK’s gas network infrastructure is utilised. This report considers the implications of decarbonisation for the future regulation of the gas grid.<br/>The CCC’s 5th Carbon Budget envisaged different scenarios that would enable the UK to meet its emissions targets for 2050. These scenarios represent holistic analyses based on internally consistent combinations of different technologies which could deliver carbon reductions across different sectors of the economy.<br/>The CCC’s scenarios incorporate projections of the demand for natural gas to 2050. The scenarios imply that the volume of throughput on the gas networks1 and the nature and location of network usage is likely to change significantly to meet emissions targets. They are also characterised by significant uncertainty.<br/>Under some decarbonisation scenarios gas networks could be re-purposed to supply hydrogen instead of natural gas meaning there would be ongoing need for network infrastructure.<br/>In other scenarios gas demand in buildings is largely replaced by electric alternatives meaning portions of the low pressure gas distribution networks could be decommissioned.<br/>Patchwork scenarios are also possible in which there is a mixture of these outcomes across the country.<br/>In this project the CCC wished to assess the potential implications for gas networks under these different demand scenarios; and evaluate the associated challenges for Government and regulatory policy. The challenge for BEIS and Ofgem is how to regulate in a way that keeps options open while uncertainty persists about the best solution for the UK; and at the same time how best to make policy and regulatory decisions which would serve to reduce this uncertainty. Both Government and Ofgem have policy and regulatory levers that they can use – and we identify and evaluate such levers in this report.

In this report Quantifying Greenhouse Gas Emissions the Committee on Climate Change assesses how the UK’s greenhouse gas emissions are quantified where uncertainties lie and the implications for setting carbon budgets and measuring progress against climate change targets. The report finds that:

• The methodology for constructing the UK’s greenhouse gas inventory is rigorous but the process for identifying improvements could be strengthened.
• There is high confidence over large parts of the inventory. A small number of sectors contribute most to uncertainty and research efforts should be directed at improving these estimates.
• UK greenhouse gas emissions for 2014 were within ±3% of the estimated level with 95% confidence which is a low level of uncertainty by international standards.
• Methodology revisions in recent years have tended to increase estimated emissions but these changes have been within uncertainty margins.
• Statistical uncertainty in the current greenhouse gas inventory is low but could rise in future.
• Uncertainty also arises from sources of emissions not currently included in the inventory and from potential changes to IPCC guidelines.
• Independent external validation of greenhouse gas emissions is important and new monitoring techniques should be encouraged.
• Government should continue to monitor consumption-based greenhouse gas estimates and support continued research to improve methodology and reduce uncertainty in these estimates.

This is our sixth statutory report to Parliament on progress towards meeting carbon budgets. In it we consider the latest data on emissions and their drivers. This year the report also includes a full assessment of how the first carbon budget (2008-2012) was met drawing out policy lessons and setting out what is required for the future to stay on track for the legislated carbon budgets and the 2050 target. The report includes assessment at the level of the economy the non-traded and traded sectors the key emitting sectors and the devolved administrations. Whilst the first carbon budget has been met and progress made on development and implementation of some policies the main conclusion is that strengthening of policies will be needed to meet future budgets.

This is the Committee’s 2020 report to Parliament assessing progress in reducing UK emissions over the past year. This year the report includes new advice to the UK Government on securing a green and resilient recovery following the COVID-19 pandemic. The Committee’s new analysis expands on its May 2020 advice to the UK Prime Minister in which it set out the principles for building a resilient recovery. In its new report the Committee has assessed a wide set of measures and gathered the latest evidence on the role of climate policies in the economic recovery. Its report highlights five clear investment priorities in the months ahead:

• Low-carbon retrofits and buildings that are fit for the future
• Tree planting peatland restoration and green infrastructure
• Energy networks must be strengthened
• Infrastructure to make it easy for people to walk cycle and work remotely
• Moving towards a circular economy.

There are also opportunities to support the transition and the recovery by investing in the UK’s workforce and in lower-carbon behaviours and innovation:

• Reskilling and retraining programmes
• Leading a move towards positive behaviours
• Targeted science and innovation funding

Energy–structure–function (ESF) maps can aid the targeted discovery of porous molecular crystals by predicting the stable crystalline arrangements along with their functions of interest. Here we compute ESF maps for a series of rigid molecules that comprise either a triptycene or a spiro-biphenyl core functionalized with six different hydrogen-bonding moieties. We show that the positioning of the hydrogen-bonding sites as well as their number has a profound influence on the shape of the resulting ESF maps revealing promising structure–function spaces for future experiments. We also demonstrate a simple and general approach to representing and inspecting the high-dimensional data of an ESF map enabling an efficient navigation of the ESF data to identify ‘landmark’ structures that are energetically favourable or functionally interesting. This is a step toward the automated analysis of ESF maps an important goal for closed-loop autonomous searches for molecular crystals with useful functions.

Thermally sprayed aluminium (TSA) coatings provide protection to offshore steel structures without the use of external cathodic protection (CP) systems. These coatings provide sacrificial protection in the same way as a galvanic anode and thus hydrogen embrittlement (HE) becomes a major concern with the use of high strength steels. The effect of TSA on the HE of steel seems to remain largely unknown. Further the location of hydrogen in TSA-coated steel has not been explored. To address the above knowledge gap API 5L X80 and AISI 4137 steel coupons with and without TSA were prepared and the amount of hydrogen present in these steels when cathodically polarised to −1.1 V (Ag/AgCl) for 30 days in synthetic seawater was determined. One set of TSA-coated specimens was left at open circuit potential (OCP). The study indicates that the amount of hydrogen present in TSA-coated steel is ~100 times more than the amount found in uncoated steel and that the hydrogen seems to be largely localised in the TSA layer.

This research introduces a ‘Hydrogen Interconnector System’ (HIS) as a novel method 7 for transporting electrical energy over long distances. The system takes electricity from 8 stranded renewable energy assets converts it to hydrogen in an electrolyser plant transports 9 hydrogen to the demand centre via pipeline where it is reconverted to electricity in either a 10 gas turbine or fuel cell plant. This paper evaluates the competitiveness of the technology with 11 High Voltage Direct Current (HVDC) systems calculating the following techno-economic 12 indicators; Levelised Cost Of Electricity (LCOE) and Levelised Cost Of Storage (LCOS). The 13 results suggest that the LCOE of the HIS is competitive with HVDC for construction in 2050 14 with distance beyond 350km in case of all scenarios for a 1GW system. The LCOS is lower 15 than an HVDC system using large scale hydrogen storage in 6 out of 12 scenarios analysed 16 including for construction from 2025. The HIS was also applied to three case studies with 17 the results showing that the system outperforms HVDC from LCOS perspectives in all cases 18 and has 15-20% lower investment costs in 2 studies analysed.

Ni-based catalysts are attractive alternatives to noble metal electrocatalysts for the hydrogen evolution reaction (HER). Herein we present a dispersion-corrected density functional theory (DFT-D3) insight into HER activity on the (111) (110) (001) and (100) surfaces of metallic nickel nitride (Ni₃N). A combination of water and hydrogen adsorption was used to model the electrode interactions within the water splitting cell. Surface energies were used to characterise the stabilities of the Ni3N surfaces along with adsorption energies to determine preferable sites for adsorbate interactions. The surface stability order was found to be (111) < (100) < (001) < (110) with calculated surface energies of 2.10 2.27 2.37 and 2.38 Jm⁻² respectively. Water adsorption was found to be exothermic at all surfaces and most favourable on the (111) surface with E_ads = −0.79 eV followed closely by the (100) (110) and (001) surfaces at −0.66 −0.65 and −0.56 eV respectively. The water splitting reaction was investigated at each surface to determine the rate determining Volmer step and the activation energies (Ea) for alkaline HER which has thus far not been studied in detail for Ni₃N. The E_a values for water splitting on the Ni₃N surfaces were predicted in the order (001) < (111) < (110) < (100) which were 0.17 0.73 1.11 and 1.60 eV respectively overall showing the (001) surface to be most active for the Volmer step of water dissociation. Active hydrogen adsorption sites are also presented for acidic HER evaluated through the ΔG_H descriptor. The (110) surface was shown to have an extremely active Ni–N bridging site with ΔG_H = −0.05 eV.

Iron oxide has been widely used as an oxygen carrier material (OCM) for hydrogen production by chemical looping due to its favourable thermodynamic properties. In spite of this iron oxide loses much of its activity after redox cycling mainly due to sintering and agglomeration. Perovskites such as La_0.7Sr_0.3FeO_3-d (LSF731) have been suggested as potential candidate OCMs for hydrogen production due to their excellent oxygen transport properties and stability under cycling. However hydrogen production per cycle for a similar carrier weight is lower than with iron oxide. This work proposes the use of composite OCMs made of iron oxide clusters embedded in an LSF731 matrix. The perovskite matrix facilitates oxygen transport to the iron oxide clusters while preventing agglomeration. Two preparation methods mechanical mixing and a modified Pechini method were used to obtain composite materials with different iron oxide weight fractions 11 and 30 wt.%. The reactivity of these OCMs was studied in a thermogravimetric analyser. Hydrogen production and carrier stability were investigated in a microreactor over 25 redox cycles while periodically feeding carbon monoxide and water in order to produce carbon dioxide and hydrogen in separate streams. Hydrogen production was stable over 25 cycles for LSF731 and the composite OCM with 30 wt.% iron oxide produced by the modified Pechini method but iron oxide particles alone underwent a decrease in the hydrogen production with cycling. The hydrogen production during the 25th cycle was eight times higher for the composite material than for iron oxide alone and four times higher than for LSF731. The hydrogen production was therefore also higher than that expected from a simple combination of the iron oxide and LSF731 alone indicating a synergetic effect whereby the LSF731 may have a higher effective oxygen capacity when in the form of the composite material.

The paper presents an experimental investigation of hydrogen-diesel fuel co-combustion carried out on a naturally aspirated direct injection diesel engine. The engine was supplied with a range of hydrogen-diesel fuel mixture proportions to study the effect of hydrogen addition (aspirated with the intake air) on combustion and exhaust emissions. The tests were performed at fixed diesel injection periods with hydrogen added to vary the engine load between 0 and 6 bar IMEP. In addition a novel inecylinder gas sampling technique was employed to measure species concentrations in the engine cylinder at two inecylinder locations and at various instants during the combustion process. The results showed a decrease in the particulates CO and THC emissions and a slight increase in CO2 emissions with the addition of hydrogen with fixed diesel fuel injection periods. NOx emissions increased steeply with hydrogen addition but only when the combined diesel and hydrogen co-combustion temperatures exceeded the threshold temperature for NOx formation. The inecylinder gas sampling results showed higher NOx levels between adjacent spray cones in comparison to sampling within an individual spray cone.

As Europe is gradually moving towards a hydrogen based society it has been acknowledged that adding certain amount of hydrogen as a clean energy carrier to the existing natural gas pipeline will help reduce the CO2 emissions which contribute to the greenhouse effect. On the other hand hydrogen has been demonstrated to be able to change the behaviour of the pipeline steel such as lower toughness and faster crack growth due to hydrogen embrittlement. Therefore it is necessary that the risks associated with the failure of the pipeline carrying mixtures of natural gas and hydrogen be assessed.<br/>The study reported in this paper is part of European NATURALHY project whose aim is to investigate the possibility of using the existing natural gas transmission pipelines to convey natural gas/hydrogen mixtures. According to the EGIG database the most common cause of failure for the existing natural gas pipelines is third party damage which mainly refers to a gouge a dent/gouge combination of known geometry. Among third party damage failures 90% are the result of immediate failure i.e. leakage or rupture of the pipeline and only 10% of them are the result of delayed failure. While its not expected that hydrogen will impact the immediate failure it could increase the vulnerability of the pipe to delayed failure through the initiation or activation of crack like defects.<br/>This paper will present a methodology to predict the probability of increased failures and describe a software tool that has been developed to perform the calculations.

In the context of hydrogen production from biomass or organic waste with dark fermentation this study analysed 55 studies (339 experiments) in the literature looking for the effect of operating parameters on the process performance of dark fermentation. The effect of substrate concentration pH temperature and residence time on hydrogen yield productivity and content in the biogas was analysed. In addition a linear regression model was developed to also account for the effect of nature and pretreatment of the substrate inhibition of methanogenesis and continuous or batch operating mode. The analysis showed that the hydrogen yield was mainly affected by pH and residence time with the highest yields obtained for low pH and short residence time. High hydrogen productivity was favoured by high feed concentration short residence time and low pH. More modest was the effect on the hydrogen content. The mean values of hydrogen yield productivity and content were respectively 6.49% COD COD−1 135 mg L−1 d −1 51% v/v while 10% of the considered experiments obtained yield productivity and content of or higher than 15.55% COD COD−1 305.16 mg L−1 d −1 64% v/v. Overall this study provides insight into how to select the optimum operating conditions to obtain the desired hydrogen production.

Numerical investigations have been conducted on the effect of the internal geometry of a local contraction on the spontaneous ignition of pressurized hydrogen release through a length of tube using a 5th-order WENO scheme. A mixture-averaged multi-component approach was used for accurate calculation of molecular transport. The auto-ignition and combustion chemistry were accounted for using a 21-step kinetic scheme. It is found that a local contraction can significantly facilitate the occurrence of spontaneous ignition by producing elevated flammable mixture and enhancing turbulent mixing from shock formation reflection and interaction. The first ignition kernel is observed upstream the contraction. It then quickly propagates along the contact interface and transits to a partially premixed flame due to the enhanced turbulent mixing. The partially premixed flames are highly distorted and overlapped with each other. Flame thickening is observed which is due to the merge of thin flames. The numerical predictions suggested that sustained flames could develop for release pressure as low as 25 bar. For the release pressure of 18 bar spontaneous ignition was predicted but the flame was soon quenched. To some extent this finding is consistent with Dryer et al.'s experimental observation in that the minimum release pressure required to induce a spontaneous ignition for the release through a tube with internal geometries is only 20.4 bar.

This report sets out our advice on the fifth carbon budget covering the period 2028-2032 as required under Section 4 of the Climate Change Act; the Government will propose draft legislation for the fifth budget in summer 2016.

This report by the Committee on Climate Change (CCC) assesses the potential role of hydrogen in the UK’s low-carbon economy.

It finds that hydrogen:

• is a credible option to help decarbonise the UK energy system but its role depends on early Government commitment and improved support to develop the UK’s industrial capability
• can make an important contribution to long-term decarbonisation if combined with greater energy efficiency cheap low-carbon power generation electrified transport and new ‘hybrid’ heat pump systems which have been successfully trialled in the UK
• could replace natural gas in parts of the energy system where electrification is not feasible or is prohibitively expensive for example in providing heat on colder winter days industrial heat processes and back-up power generation
• is not a ‘silver bullet’ solution; the report explores some commonly-held misconceptions highlighting the need for careful planning

The report’s key recommendations are:

• Government must commit to developing a low-carbon heat strategy within the next three years
• Significant volumes of low-carbon hydrogen should be produced in a carbon capture and storage (CCS) ‘cluster’ by 2030 to help the industry grow
• Government must support the early demonstration of the everyday uses of hydrogen in order to establish the practicality of switching from natural gas to hydrogen
• There is low awareness amongst the general public of reasons to move away from natural gas heating to low-carbon alternatives
• A strategy should be developed for low-carbon heavy goods vehicles (HGVs) which encourages a move away from fossil fuels and biofuels to zero-emission solutions by 2050

As part of its statutory role the Committee provides annual reports to Parliament on the progress that Government is making in meeting carbon budgets and in reducing emissions of greenhouse gases.<br/>Meeting Carbon Budgets – ensuring a low-carbon recovery is the Committee’s 2nd progress report. Within this report we assess the latest emissions data and determine whether emissions reductions have occurred as a result of the recession or as a result of other external factors. We assess Government’s progress towards achieving emissions reductions in 4 key areas of: Power Buildings and Industry Transport and Agriculture.

If the hydrogen economy is to progress more hydrogen refuelling stations are required. In the short term in the absence of a hydrogen distribution network the most likely means of supplying the refuelling stations will be by liquid hydrogen road tanker. This development will clearly increase the number of tanker offloading operations significantly and these may need to be performed in more challenging environments with close proximity to the general public. The work described in this paper was commissioned in order to determine the hazards associated with liquid hydrogen spills onto the ground at rates typical for a tanker hose failure during offloading.

Experiments have been performed to investigate spills of liquid hydrogen at a rate of 60 litres per minute. Measurements were made on both unignited and ignited releases.

These include:

• Concentration of hydrogen in air thermal gradient in the concrete substrate liquid pool formation and temperatures within the pool
• Flame velocity within the cloud thermal radiation IR and visible spectrum video records.
• Sound pressure measurements
• An estimation of the extent of the flammable cloud was made from visual observation video IR camera footage and use of a variable position ignition source.

This publication by the Department for Business Energy and Industrial Strategy (BEIS) brings together heat networks investment opportunities in England and Wales. The opportunities present a wide range of projects supported through the development stages by the Heat Networks Delivery Unit (HNDU) and projects seeking capital support from the Heat Networks Investment Project (HNIP).

The publication includes a list of one-page summaries for each of the heat network projects supported by BEIS which set out details of HNDU and HNIP projects where projects have provided enough detail in time for publication.

For HNIP this represents projects which have submitted at least a pre-application to the Delivery Partner Triple Point Heat Networks Investment Management since the scheme opened in February 2019. As a number of the projects are at different stages of development some of the costs aren’t currently available or will be subject to project consent and change as they progress through the project lifecycle.

Related Document: Heat Network Detailed Project Development Resource: Guidance on Strategic and Commercial Case

The key project objectives include:

• Understand the range size type mode of operation and control system of installed gas engines in the UK. This will include equipment for CHP and for stand-by power operation.
• Produce data sets on the impact of hydrogen on gas engine operational performance.
• Develop knowledge on the impact of hydrogen content on the operation of the gas engine including overall efficiency changes to emissions profiles overall system operability.
• Providing outline guidance on a potential hydrogen limit that should be considered regarding use of natural gas/hydrogen mixed fuels in gas engines.
• Outlining a high-level view on the reliability and impact on maintenance and replacement regimes if gas engines operate on natural gas/hydrogen mixed fuels for extended time periods.
• Highlight any existing barriers to use of natural gas and hydrogen blends in gas engine and through contact with OEMs develop an understanding of future technology developments that may be needed to enable the use of “high” hydrogen blends.

The main aim is to characterise the impact of using natural gas/hydrogen fuel mixtures on the operation of gas engines used in CHP systems.

The output from this project will also inform the HyDeploy NIC project in relation to potential hydrogen content limits. The project will be presented at the IGEM Gas Quality Working Group (IGEM GQWG).

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.

Underground or partial underground tunnels form a very important part of modern road transportation systems. As the development of hydrogen cars advancing into the markets it is unavoidable in the near future that hydrogen cars would become the users of ordinary road tunnels. This paper discusses potential fire scenarios and fire hazards of hydrogen cars in road tunnels and implications on the fire safety measures and ventilation systems in existing tunnels. The information needed for carry out risk assessment of hydrogen cars in road tunnels are discussed. hydrogen has a low ignition energy and wide flammable range suggesting that leaks have a high probability of ignition and result hydrogen flame. CFD simulations of hydrogen fires in a full scale 5m by 5m square cross-section tunnel were carried out. The effect of the ventilation on controlling the back-layering and the downstream flame are discussed.

The Aberdeen Vision Project could deliver CO2 savings of 1.5MtCO2/y compared with natural gas. A dedicated pipeline from St Fergus to Aberdeen would enable the phased transfer of the Aberdeen regional gas distribution system to 20% then 100% hydrogen.

The study has demonstrated that 2% hydrogen can be injected into the National Transmission System (NTS) at St Fergus and its distribution through the system into the gas distribution network. Due to unique regional attributes the Aberdeen region could lead the UK in the conversion to largescale clean hydrogen. A 200MW hydrogen generation plant is planned to suit 2% blend into the NTS followed by a build out to supply the Aberdeen gas networks and to enable low cost hydrogen transport applications.

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.

It has been suggested that separation or safety distances for pressurised hydrogen storage can be reduced by the inclusion of walls or barriers between the hydrogen storage and vulnerable plant or other items. Various NFPA codes (1) suggest the use of 60° inclined fire barriers for protection against jet flames in preference to vertical ones.<br/>This paper describes a series of experiments performed in order to compare the performance of 60° barriers with that of 90° barriers. Their relative efficiency at protecting from thermal radiation and blast overpressure was measured together with the propensity for the thermal radiation and blast overpressure to be reflected back to the source of the leak. The work was primarily focused on compressed H2 storage for stationary fuel cell systems which may be physically separated from a fuel cell system or could be on board such a system. Different orifice sizes were used to simulate different size leaks and all releases were made were from storage at 200 bar.<br/>Overall conclusions on barrier performance were made based on the recorded measurements.

The EC funded Naturalhy project is assessing the potential for using the existing gas infrastructure for conveying hydrogen as a mixture with natural gas (methane). The hydrogen could then be removed at a point of use or the natural gas/hydrogen mixture could be burned in gas-fired appliances thereby providing reduced carbon emissions compared to natural gas. As part of the project the impact on the safety of the gas system resulting from the addition of hydrogen is being assessed. A release of a natural gas/hydrogen mixture within a vented enclosure (such as an industrial housing of plant and equipment) could result in a flammable mixture being formed and ignited. Due to the different properties of hydrogen the resulting explosion may be more severe for natural gas/hydrogen mixtures compared to natural gas. Therefore a series of large scale explosion experiments involving methane/hydrogen mixtures has been conducted in a 69.3 m3 enclosure in order to assess the effect of different hydrogen concentrations on the resulting explosion overpressures. The results showed that adding up to 20% by volume of hydrogen to the methane resulted in a small increase in explosion flame speeds and overpressures. However a significant increase was observed when 50% hydrogen was added. For the vented confined explosions studied it was also observed that the addition of obstacles within the enclosure representing congestion caused by equipment and pipework etc. increased flame speeds and overpressures above the levels measured in an empty enclosure. Predictions of the explosion overpressure and flame speed were also made using a modified version of the Shell Global Solutions model SCOPE. The modifications included changes to the burning velocity and other physical properties of methane/hydrogen mixtures. Comparisons with the experimental data showed generally good agreement.

Decarbonization of the shipping sector is inevitable and can be made by transitioning into low‐ or zero‐carbon marine fuels. This paper reviews 22 potential pathways including conventional Heavy Fuel Oil (HFO) marine fuel as a reference case “blue” alternative fuel produced from natural gas and “green” fuels produced from biomass and solar energy. Carbon capture technology (CCS) is installed for fossil fuels (HFO and liquefied natural gas (LNG)). The pathways are compared in terms of quantifiable parameters including (i) fuel mass (ii) fuel volume (iii) life cycle (Well‐To‐ Wake—WTW) energy intensity (iv) WTW cost (v) WTW greenhouse gas (GHG) emission and (vi) non‐GHG emissions estimated from the literature and ASPEN HYSYS modelling. From an energy perspective renewable electricity with battery technology is the most efficient route albeit still impractical for long‐distance shipping due to the low energy density of today’s batteries. The next best is fossil fuels with CCS (assuming 90% removal efficiency) which also happens to be the lowest cost solution although the long‐term storage and utilization of CO2 are still unresolved. Biofuels offer a good compromise in terms of cost availability and technology readiness level (TRL); however the non‐GHG emissions are not eliminated. Hydrogen and ammonia are among the worst in terms of overall energy and cost needed and may also need NOx clean‐up measures. Methanol from LNG needs CCS for decarbonization while methanol from biomass does not and also seems to be a good candidate in terms of energy financial cost and TRL. The present analysis consistently compares the various options and is useful for stakeholders involved in shipping decarbonization.

Plasmonic Ni nanoparticles were incorporated into LaFeO₃ photocathode (LFO-Ni) to excite the surface plasmon resonances (SPR) for enhanced light harvesting for enhancing the photoelectrochemical (PEC) hydrogen evolution reaction. The nanostructured LFO photocathode was prepared by spray pyrolysis method and Ni nanoparticles were incorporated on to the photocathode by spin coating technique. The LFO-Ni photocathode demonstrated strong optical absorption and higher current density where the untreated LFO film exhibited a maximum photocurrent of 0.036 mA/cm² at 0.6 V vs RHE and when incorporating 2.84 mmol Ni nanoparticles the photocurrent density reached a maximum of 0.066 mA/cm² at 0.6 V vs RHE due to the SPR effect. This subsequently led to enhanced hydrogen production where more than double (2.64 times) the amount of hydrogen was generated compared to the untreated LFO photocathode. Ni nanoparticles were modelled using Finite Difference Time Domain (FDTD) analysis and the results showed optimal particle size in the range of 70–100 nm for Surface Plasmon Resonance (SPR) enhancement.

We analyze the feasibility of a novel hydrogen fuel cell electric generator to provide power with zero noise and emissions for myriad ground based applications. The hydrogen fuel cell electric generator utilizes a novel scalable apparatus that safely generates hydrogen (H2) on demand according to a novel method using a controlled chemical reaction between water (H2O) and sodium (Na) metal that yields hydrogen gas of sufficient purity for direct use in fuel cells without risk of contaminating sensitive catalysts. The sodium hydroxide (NaOH) byproduct of the hydrogen producing reaction is collected within the apparatus for later reprocessing by electrolysis to recover the Na reactant. The detailed analysis shows that the novel hydrogen fuel cell electric generator will be capable of meeting the clean power requirements for residential and commercial buildings including single family homes and light commercial establishments under a wide range of geographic and climatic conditions.

The higher cost of green hydrogen in comparison to its competitors is the most important barrier to its increased use. Although the cost of renewable electricity is considered to be the key obstacle challenges associated with electrolysers are another major issue that have important implications for the cost reduction of green hydrogen. This paper analyses the electrolysis process from technological economic and policy perspectives. It first provides a comparative analysis of the main existing electrolyser technologies and identifies key trade-offs in terms of cost scarcity of materials used technology readiness and the ability to operate in a flexible mode (which enables them to be coupled with variable renewables generation). The paper then identifies the main cost drivers for each of the most promising technologies and analyses the opportunities for cost reduction. It also draws upon the experience of solar and wind power generation technologies with respect to gradual cost reduction and evaluates development paths that each of the main electrolyser technology types could take in the future. Finally the paper elaborates on the policy mechanisms that could additionally foster cost reduction and the overall business development of electrolyser technologies.

The research paper can be found on their website

In the long term the key to the development of a hydrogen economy is a full infrastructure to support it which include means for the delivery and storage of hydrogen at the point of use eg at hydrogen refuelling stations for vehicles. As an interim measure to allow the development of refuelling stations and rapid implementation of hydrogen distribution to them liquid hydrogen is considered the most efficient and cost effective means for transport and storage.

The Health and Safety Executive have commissioned the Health and Safety Laboratory to identify and address issues relating to bulk liquid hydrogen transport and storage and update/develop guidance for such facilities. This position paper the first part of the project assesses the features of the transport and storage aspects of the refuelling stations that are now being constructed in the UK compares them to existing guidance highlights gaps in the regulatory regime and identifies outstanding safety issues. The findings together with the results of experiments to improve our understanding of the behaviour of liquid hydrogen will inform the development of the guidance for refuelling facilities

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On April 7 2021 OIES with and the Kuwait Foundation for the Advancement of Sciences (KFAS) held the annual OIES-KFAS Workshop on Energy Transition Post-Pandemic in the Gulf. During the hydrogen session a paper titled “Opportunity and Cost of Green Hydrogen in Kuwait: A Preliminary Assessment” co-authored by Dr. Manal Shehabi was presented.

Like others states in the GCC Kuwait is seeking to explore hydrogen as part of its energy transition projects. The presentation highlights key technological opportunities for green hydrogen in Kuwait followed by a techno-economic assessments of producing it. Results of utilized hydrogen production model show that for production in 2032 average levelized cost of hydrogen (LCOH) is $3.23/kg using PEM technology & $4.41/kg using SOEC technology.  Results indicate that green hydrogen in Kuwait is more competitive than in other regions but currently not competitive (>$1.5/kg) with oil coal and gas in absence of carbon taxes.

The research paper can be found on their website

Activated carbons with different surface chemistry and porous textures were used to study the mechanism of electrochemical hydrogen and oxygen evolution in supercapacitor devices. Cellulose precursor materials were activated with different potassium hydroxide (KOH) ratios and the electrochemical behaviour was studied in 6 M KOH electrolyte. In situ Raman spectra were collected to obtain the structural changes of the activated carbons under severe electrochemical oxidation and reduction conditions and the obtained data were correlated to the cyclic voltammograms obtained at high anodic and cathodic potentials. Carbon-hydrogen bonds were detected for the materials activated at high KOH ratios which form reversibly under cathodic conditions. The influence of the specific surface area narrow microporosity and functional groups in the carbon electrodes on their chemical stability and hydrogen capture mechanism in supercapacitor applications has been revealed.

The “SUpport to SAfety aNAlysis of Hydrogen and Fuel Cell Technologies (SUSANA)” project aims to support stakeholders using Computational Fluid Dynamics (CFD) for safety engineering design and assessment of FCH systems and infrastructure through the development of a model evaluation protocol. The protocol covers all aspects of safety assessment modelling using CFD from release through dispersion to combustion (self-ignition fires deflagrations detonations and Deflagration to Detonation Transition - DDT) and not only aims to enable users to evaluate models but to inform them of the state of the art and best practices in numerical modelling. The paper gives an overview of the SUSANA project including the main stages of the model evaluation protocol and some results from the on-going benchmarking activities.

This paper aims to improve prediction capability of the vent sizing correlation presented in the form of functional dependence of the dimensionless deflagration overpressure on the turbulent Bradley number similar to our previous studies. The correlation is essentially upgraded based on recent advancements in understanding and modelling of combustion phenomena relevant to hydrogen-air vented deflagrations and unique large-scale tests carried out by different research groups. The focus is on hydrogen-air deflagrations in low-strength equipment and buildings when the reduced pressure is accepted to be  below 0.1 MPa. The combustion phenomena accounted for by the correlation include: turbulence generated by the flame front itself; leading point mechanism stemming from the preferential diffusion of hydrogen in air in stretched flames; growth of the fractal area of the turbulent flame surface; initial turbulence in the flammable mixture; as well as effects of enclosure aspect ratio and presence of obstacles. The correlation is validated against the widest range of experimental conditions available to date (76 experimental points). The validation covers a wide range of test conditions: different shape enclosures of volume up to 120 m3; initially quiescent and turbulent hydrogen-air mixtures; hydrogen concentration in air from 6% to 30% by volume; ignition source location at enclosure centre near and far from a vent; empty enclosures and enclosures with obstacles.

Successful transition to a hydrogen economy calls for a deep understanding of the risks associated with its widespread use. Accidental ignition of hydrogen by hot surfaces is one of such risks. In the present study we investigated the effect that rotation has on the reported ignition thresholds by numerically determining the minimum surface temperature required to ignite stoichiometric hydrogen-air using a hot horizontal cylinder rotating at various angular velocities ω. Numerical experiments showed a weak but interesting dependence of the ignition thresholds on rotation: the ignition thresholds increased by 8 K from 931 K to 939 K with increasing angular velocity (0 ≤ ω ≤ 240 rad/s). A further increase to ω = 480 rad/s resulted in a decrease in ignition surface temperature to 935 K. Detailed analysis of the flow patterns inside the vessel and in close proximity to the hot surface brought about by the combined effect of buoyancy and rotation as well as of the distribution of the wall heat flux along the circumference of the cylinder support our previous findings in which regions where temperature gradients are small were found to be prone to ignition.

Existing regulations and standards for the approval of composite cylinders in hydrogen service are currently based on deterministic criteria (ISO 11119-3 UN GTR No. 13). This paper provides a systematic analysis of the load cycle properties resulting from these regulations and standards. Their characteristics are compared with the probabilistic approach of the BAM. Based on Monte-Carlo simulations the available design range of all concepts is compared. In addition the probability of acceptance for potentially unsafe design types is determined.

The absorption of CO2 is of importance in carbon capture utilization and storage technology for greenhouse gas control. In the present work we clarified the mechanism of how metal-based ionic liquids (MBILs) Bmim[XCln]m (X is the metal atom) enhance the CO2 absorption capacity of ILs via performing molecular dynamics simulations. The sparse hydrogen bond interaction network constructed by CO2 and MBILs was identified through the radial distribution function and interaction energy of CO2-ion pairs which increase the absorption capacity of CO2 in MBILs. Then the dynamical properties including residence time and self-diffusion coefficient confirmed that MBILs could also promote the diffusion process of CO2 in ILs. That's to say the MBILs can enhance the CO2 absorption capacity and the diffusive ability simultaneously. Based on the analysis of structural energetic and dynamical properties the CO2 absorption capacity of MBILs increases in the order Cl− → [ZnCl4]2-→ [CuCl4]2-→ [CrCl4]- → [FeCl4]- revealing the fact that the short metal–Cl bond length and small anion volume could facilitate the performance of CO2 absorbing process. These findings show that the metal–Cl bond length and effective volume of the anion can be the effective factors to regulate the CO2 absorption process which can also shed light on the rational molecular design of MBILs for CO2 capture and other key chemical engineering processes such as IL-based gas sensors nano-electrical devices and so on.

The Energy Innovation Needs Assessment (EINA) aims to identify the key innovation needs across the UK’s energy system to inform the prioritisation of public sector investment in low-carbon innovation. Using an analytical methodology developed by the Department for Business Energy & Industrial Strategy (BEIS) the EINA takes a system level approach and values innovations in a technology in terms of the system-level benefits a technology innovation provides. This whole system modelling in line with BEIS’s EINA methodology was delivered by the Energy Systems Catapult (ESC) using the Energy System Modelling Environment (ESMETM) as the primary modelling tool.

To support the overall prioritisation of innovation activity the EINA process analyses key technologies in more detail. These technologies are grouped together into sub-themes according to the primary role they fulfil in the energy system. For key technologies within a sub-theme innovations and business opportunities are identified. The main findings at the technology level are summarised in sub-theme reports. An overview report will combine the findings from each sub-theme to provide a broad system-level perspective and prioritisation.

This EINA analysis is based on a combination of desk research by a consortium of economic and engineering consultants and stakeholder engagement. The prioritisation of innovation and business opportunities presented is informed by a workshop organised for each sub-theme assembling key stakeholders from the academic community industry and government.

This report was commissioned prior to advice being received from the CCC on meeting a net zero target and reflects priorities to meet the previous 80% target in 2050. The newly legislated net zero target is not expected to change the set of innovation priorities rather it will make them all more valuable overall. Further work is required to assess detailed implications.

Hydrogen boilers have been developed by Worcester Bosch and Baxi and are being trialled in demonstration houses. They look and feel just like the boilers we use today. Hydrogen produces no carbon when used and a hydrogen gas network could provide the least disruptive route to a net zero carbon future.

This paper summarises the results from a blind-prediction study for models developed for estimating the consequences of vented hydrogen deflagrations. The work is part of the project Improving hydrogen safety for energy applications through pre-normative research on vented deflagrations (HySEA). The scenarios selected for the blind-prediction entailed vented explosions with homogeneous hydrogen-air mixtures in a 20-foot ISO container. The test program included two configurations and six experiments i.e. three repeated tests for each scenario. The comparison between experimental results and model predictions reveals reasonable agreement for some of the models and significant discrepancies for others. It is foreseen that the first blind-prediction study in the HySEA project will motivate developers to improve their models and to update guidelines for users of the models.

Since early 2020 Turkey has been considering the role of hydrogen in its energy future with a view to producing a hydrogen strategy in the next few months.  Unlike many other countries considering the role of hydrogen Turkey has only recently (October 2021) ratified the Paris Agreement addressing climate change and its interest is driven more by geopolitical strategic and energy security concerns.   Specifically with concerns about the high share of imported energy particularly gas from Russia it sees hydrogen as part of a policy to increase indigenous energy production.   Turkey already has a relatively high share of renewable power generation particularly hydro and recent solar auctions have resulted in low prices leading to a focus on potential green hydrogen production.  However it still generates over half of its electricity from fossil fuel including over 25% from coal and lignite.  Against that background it provides an interesting case study on some of the key aspects that a country needs to consider when looking to incorporate low-carbon hydrogen into the development of their energy economy.

The research paper can be found on their website

The reproducibility of fire test protocol in the UN Global Technical Regulation on Hydrogen and Fuel Cell Vehicles (GTR#13) is not satisfactory. Results differ from laboratory to laboratory and even at the same laboratory when fires of different heat release (HRR) rate are applied. This is of special importance for fire test of tank without thermally activated pressure relief devise (TPRD) the test requested by firemen. Previously the authors demonstrated a strong dependence of tank fire resistance rating (FRR) i.e. time from fire test initiation to moment of tank rupture on the HRR in a fire. The HRR for complete combustion at the open is a product of heat of combustion and flow rate of a fuel i.e. easy to control in test parameter. It correlates with heat flux to the tank from a fire – the higher HRR the higher heat flux. The control of only temperature underneath a tank in fire test as per the current fire test protocol of UN GTR#13 without controlling HRR of fire source is a reason of poor fire test reproducibility. Indeed a candle flame can easily provide a required by the protocol temperature in points of control but such test arrangements could never lead to tank rupture due to fast heat dissipation from such tiny fire source i.e. insufficient and very localised heat flux to the tank. Fire science requires knowledge of heat flux along with the temperature to characterise fire dynamics. In our study published in 2018 the HRR is suggested as an easy to control parameter to ensure the fire test reproducibility. This study demonstrates that the use of specific heat release rate HRR/A i.e. HRR in a fire source divided by the area of the burner projection A enables testing laboratories to change freely a burner size depending on a tank size without affecting fire test reproducibility. The invariance of FRR at its minimum level with increase of HRR/A above 1 MW/m2 has been discovered first numerically and then confirmed by experiments with different burners and fuels. The validation of computational fluid dynamics (CFD) model against the fire test data is presented. The numerical experiments with localised fires under a vehicle with different HRR/A are performed to understand the necessity of the localised fire test protocol. The understanding of fire test underlying physics will underpin the development of protocol providing test reproducibility.

HSE maintains a national network of doctors appointed doctors and approved medical examiners of divers who are appointed to deliver certain vital functions under our regulatory framework.1 Over the last year or so we have been reaching out to them and offering training and networking opportunities so that we can learn from each other. Their intelligence from real workplaces helps ensure that our medical approach is grounded by what actually happens and this helped us ensure that our health and work strategy took account of their views. I think that it is increasingly important to share our approaches and our  research outcomes on the global stage in an attempt to learn from other researchers around the world. A good example is the work described in this report on the artificial stone issue. I have been lucky enough to work with the Australian research group who identified an epidemic of silicosis from this exposure in their country and helped to facilitate some cross-comparison of materials with our hygienists and measurement scientists. The dialogue continues and I hope that by doing so we can help to prevent such an epidemic from occurring in the UK.<br/>All HSE research findings are published as soon as we are able to do this and this demonstrates both my and Andrew Curran’s commitment to ensure that we publish the evidence we generate to make workplaces healthier for all.