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.