The UK has made considerable progress decarbonising its power sector. However, decarbonising space-heating has been much more challenging. Currently, space-heating accounts for ~1/3 of the country's CO2 emissions. This must change to achieve Net Zero Two main low-carbon heating solutions are being considered: 1) direct heating from hydrogen combustion in boilers and 2) electrically-driven heat-pumping. Although both are promising, there are serious challenges to overcome. National Grid and other gas network operators have confirmed the technical feasibility of distributing hydrogen through the existing gas infrastructure, which connects >23 million properties. Hydrogen boilers are not commercially available yet, but they are well underway. Hydrogen can be made from renewable electricity; however, a big downside is that when combusted in boilers, the amount of energy we recover is only ~60% of what we spent making it. It is not a very efficient process. Electric heat pumps have a much higher efficiency. The amount of heat they provide can be as much as 3x the amount of electricity they consume. So, for every 1kWh of electricity used, a heat pump will give 3kWh of heat. This in stark contrast to the 0.6 kWh that would be obtained if the same 1kWh of electricity was used to make hydrogen, and that hydrogen was combusted in a boiler. Although it seems like using electric heat pumps is the way to go, there is a major problem. The electricity grid does not have the capacity to support their use in any significant fraction of UK homes. The reason for this is the huge energy demand for heating purposes. During winter, the peak demand in the gas network is more than 4x than the peak demand in the electricity grid. But also, during the first few hours of each day, the gas network experiences power-ramps that are 10x greater than what the electricity grid sees. The electricity grid does not have the capacity to provide the same levels of energy and power as the gas network. The upgrades required to enable the electricity grid to take on the gas network's duty are too expensive to be viable. It is precisely these challenges that are holding back the UK's transition to low-carbon heating. This postdoctoral fellowship addresses this issue by investigating and developing a deep understanding of a novel set of technologies called 'High-Performance Heat-Powered Heat-Pumps (HP3)'. These innovative heating systems combine the best attributes of the two main low-carbon options being considered (hydrogen boilers and electric heat pumps) and at the same time, removes their drawbacks. The widespread adoption of HP3 systems will enable the gas network to distribute hydrogen to homes across the country and therefore to continue to supply the enormous demand for energy during winter. HP3 systems deliver a greater benefit per unit of H2 consumed in comparison to hydrogen boilers. This will help the gas network to supply hydrogen to even more homes but also, consumers will enjoy reduced bills. By keeping the gas network in service, the use of HP3 systems will avoid placing an overwhelmingly large load on the electricity grid that would be created if the country adopted electrically-driven heat-pumping. This fellowship will develop detailed computational models to simulate the operation of HP3 systems in order to understand the effect that different design and operational variables have on their performance. Special focus will be given to exploring ultra-high operating pressures at this can lead to reductions in the overall cost of the units. A laboratory prototype will be developed and tested to demonstrate the functionality concept. This work has real prospects to be transformational in two different ways: (i) triggering a step-change in the UK 'boiler industry' towards more sophisticated and much higher-value products and (ii) accelerating the achievement of Net Zero by improving affordability.

Project Partners: Transport Scotland, Scottish Water, SGN, SEPA, Inverclyde Council, National Centre for Resilience, Climate Ready Clyde, Adaptation Scotland/SNIFFER a) Our objective is to develop a game based approach to understand climate change impacts and adaptation on interdependent infrastructures. Using Inverclyde as a case-study, we will develop a transferable approach that identifies local scale interactions and interdependencies, and allows diverse infrastructure partners to jointly think of adaptation solutions. b) Inverclyde is a local authority in the west of the Greater Glasgow region. The urban coastal strip forms a vulnerable corridor. Our project will bring together major infrastructure partners (Transport Scotland, Scottish Water, SGN), with regional partners (Clydeplan, Inverclyde Council), SEPA and national knowledge brokers (Adaptation Scotland, National Resilience Centre) in a 6 month project that focuses on using a game to develop a shared understanding of key multi-hazard risks to infrastructure in the region due to climate change. c) Despite increasing capability to assess specific climate risks to infrastructure, our partners need to better understand vulnerability of infrastructure systems to climate-influenced environmental risks, and key interdependencies between them. Key challenges identified include: (1) translating climate projections into impacts on infrastructure - in particular with event succession, cumulative effects, long-term stresses, and/or multiple hazards; (2) identifying key location hotspots where there is a high multi-operator composite risk that may not be recognised by current practice; (3) understanding interdependencies between infrastructures operations, including varying resilience levels in regulation and license conditions; (4) considering impact of services provided by infrastructures and the socio-economic implications of service degradation or failure. d) At the end of the project, our partners will have: (1) an improved understanding of why and when service interruptions may occur; (2) an improved understanding of the interactions between multiple infrastructure networks; (3) identified key hotspots where the greater risk may not be currently recognised; (4) identified key risks; and (5) access to a game approach for identifying key risks. e) We plan a 6 month project employing one PDRA and contracting out design and development of the card game component. The total cost of the project is £50,777.45 at 80% FEC (£62,596.81 at 100% FEC).

This project will assess the potential value of hydrogen to the UK as part of a transition to a low carbon economy. It will assess the potential demand for and value of hydrogen in different markets across the energy system and will analyse the supply chain required to produce and deliver that hydrogen, including the supply of hydrogen from using electrolysers for load balancing in the UK electricity system with a high penetration of renewable electricity. In the short-term, hydrogen electrolysers can support electricity system load balancing as the proportion of intermittent renewables increases. The Universities of Edinburgh and Reading have led efforts to characterise the UK wind power resource and to understand how new developments can be incorporated into the UK electricity system. This project will extend the models developed at these institutions to assess the indirect value of hydrogen in supporting a high penetration of renewable electricity by avoiding electricity network reinforcement. It will also link these models with the UK energy system model at UCL (UK TIMES) to assess the direct value of electrolysed hydrogen to companies, if the hydrogen is used in the gas network (power-to-gas), as an industrial feedstock, as a transport fuel or for large-scale storage as part of the electricity system. The models will identify the most appropriate locations for electrolysis deployment and the timescales on which they should be deployed. In the medium-term, the most important use of hydrogen is likely to be in the transport sector. UCL has recently examined how a hydrogen supply chain might develop across the UK using a new spatially-explicit infrastructure planning model called SHIPMod. This project will add a number of new features to this model including hydrogen pipelines and finer temporal disaggregation to link with the electrolysis parts of the network models developed at Edinburgh. It will be used to assess the value of hydrogen supply infrastructure and will identify the optimum deployment of infrastructure across the UK. In the longer term, hydrogen is a zero-carbon option to replace natural gas for heat generation. UCL have examined the potential for converting the natural gas networks to use hydrogen and to examine the long-term prospects for micro-CHP to replace boilers. This project will build on this research with the aims of: (i) assessing the value of hydrogen to the UK for heat provision; (ii) understanding the impact of hydrogen on the gas distribution networks; and, (iii) examining how using hydrogen for heat as well as transport would impact the development of a hydrogen supply infrastructure. Hydrogen infrastructure represents a risky investment in the early stages of a transition because of the highly uncertain future uptake of hydrogen vehicles. It is important to factor the cost of this risk into the value of hydrogen. We will use a mixture of real options and stochastic programming analysis, using the UK TIMES energy system model and the SHIPMod infrastructure planning model, to account for and manage risk in different scenarios (including using hydrogen only for transport or using it for both transport and heat). Hence we will identify scenarios with lower investment risk and we will identify policies that will reduce these risks and facilitate the development of a hydrogen economy. This project will build on existing research projects, including using models developed by the EPSRC H2FC Supergen Hub and the EPSRC Adaptation and Resilience in Energy Systems (ARIES) project. Funding for hydrogen research in the UK is currently almost exclusively focused on technology development and this project will fill an important gap in the funding landscape by taking a whole systems approach to understanding the potential role of hydrogen in future UK low-carbon energy system configurations.

Increasing reliance on intermittent renewable electricity sources makes balancing supply to demand difficult. This will become increasingly challenging as the proportion of renewables increases into the future. One solution is the large-scale geological storage of energy in the form of hydrogen. Electricity generation from stored hydrogen can balance summer to winter seasonal energy demands, with the added potential for hydrogen to repurpose the gas grid and replace methane for heating. This is significant as the heating of buildings is currently the largest source of carbon emissions in the UK, exceeding those for electricity generation. However, the underground storage of hydrogen in porous rocks has not yet been demonstrated commercially. This project hence uses state-of-the-art laboratory experiments to address questions which require insight before commercial trials occur, focusing on the geological (underground) storage of hydrogen in geographically-widespread porous rocks. Storage of hydrogen underground is well established in caverns of halite (salt). However, in the UK this type of geology is restricted only to Teesside, Northern Ireland and Cheshire, with long and costly transport to consumers elsewhere. Methane gas in the UK is already stored underground onshore in porous reservoirs and offshore in re-purposed natural gas fields, and that provides insight to operational designs and challenges. The project partners have expertise in hydrocarbon reservoirs, geological assessment of CO2 storage, and compressed air energy storage using porous rocks. WP1 Hydrogen reactivity examines whether the hydrogen could react chemically with the rocks into which it is injected or the overlying seal rock, which could prevent the gas from being recovered and used. Controlled laboratory experiments with hydrogen injection into porous rock at subsurface temperatures and pressures will identify and quantify likely chemical reactions. WP2 Petrophysics assesses how effectively hydrogen migrates through water-filled porous media, and how much of the injected hydrogen can actually be recovered from the rock. Because the rock is made of solid grains with a network of pore spaces between, capillary forces naturally trap some of the hydrogen. How much is trapped affects the commercial viability of the whole process. Laboratory-based experimentation will inject hydrogen into rock samples to help answer this question. CT scanning provides live 3D images of the hydrogen retention in the rock pores. WP3 Flow simulation uses digital computer models of fluid flow adapted from hydrocarbon simulation to scale up from laboratory experiments to an underground storage site. Hydrogen reactive flow properties from WP1 and WP2 will be used to calibrate numerical fluid flow software codes. These models can calculate how efficiently the hydrogen can be injected, and predict how much of the hydrogen can be recovered during operation. Volumes and types of cushion gas to be left in the reservoir as a precaution to maintain operation pressure and minimise water encroachment during withdrawal periods will also be assessed. WP4 Public perception considers how societal familiarity with hydrogen may be much lower compared to natural gas. A key objective of the project is to ascertain at an early stage how citizens and key opinion shapers feel about hydrogen storage underground, and to engage civil society with the research and development process to ensure that hydrogen storage develops in a way that is both technically feasible and socially acceptable. WP5 Project management, industry advisory board, communication and outreach are essential in this type of project. Digital updates will be posted on a dedicated project website and social media channels, with presentations made at academic and industry events. Public project reports and, eventually, peer reviewed publications will provide an open access record of project progress.