The production, storage, distribution and conversion of hydrogen is a rapidly emerging candidate to help decarbonise the economy. Here we focus on its role to support the integration of offshore renewable energy (ORE), a topic of increasing importance to the UK given the falling costs of offshore wind generation (with prices expected to drop to 25% of 2017 by 2023) and Government ambition. Indeed, the latest BEIS scenarios include more than 120 GW of offshore wind, and even up to 233GW in some scenarios. This brings with it significant challenges to the electricity infrastructure in terms of our ability to on-shore and integrate these variable energy flows, across a wide range of timeframes. Current ORE plants composed of fixed offshore wind structures are sited relatively close to land in shallow water and use systems of offshore cables and substations to transform the electricity produced, transmit it to the shore and connect to the grid. However, in order to exploit the full renewable energy potential and requirements for the 2050 net zero target, offshore wind farms will need to be sited further offshore and in deeper waters. This brings possibilities into consideration in which transporting the energy to shore via an alternative vector such as hydrogen could become the most attractive route. Hence we consider both on-shore and off-shore hydrogen generation. Not only can hydrogen be an effective means to integrate offshore wind, but it is also increasingly emerging as an attractive low carbon energy carrier to support the de-carbonisation of hard to address sectors such as industrial heat, chemicals, trucks, heavy duty vehicles, shipping, and trains. This is increasingly recognised globally, with significant national commitments to hydrogen in France, China, Canada, Japan, South Korea, Germany, Portugal, Australia and Spain in the last three years alone, along with the recent launch of a European hydrogen strategy, and the inclusion of hydrogen at scale in the November 2020 UK Government Green plan. Most of the focus of these national strategies is on the production of 'green' hydrogen using electrolysis, driven by renewable electricity. However, there remains interest in some countries, the UK being one example, in 'blue' hydrogen, which is hydrogen made from fossil fuels coupled with carbon capture and storage and hence a low carbon rather than zero carbon hydrogen. Today, 96% of hydrogen globally is produced from unabated fossil fuels, with 6% of global natural gas, and 2% of coal, consumption going to hydrogen production, primarily for petrochemicals, contributing around 830 million tonnes of carbon dioxide emissions per year. Currently green hydrogen is the most expensive form of hydrogen, with around 60-80% of the cost coming from the cost of the electrical power input. A critical factor that influences this is the efficiency of the electrolyser itself, and in turn the generator used to convert the green hydrogen back into power when needed. In this work we focus on the concept of a reversible electrolyser, which is a single machine that can both produce power in fuel cell mode, and produce hydrogen in electrolyser mode. Electrolysers and fuel cells fall into one of two categories: low-temperature (70-120C) and high temperature (600-850C). While low temperature electrolyser and fuel cell systems are already commercially available, their relatively low combined round-trip efficiency (around 40%) means that the reversible solid oxide cell (rSOC), which can operate at high temperatures (600-900C) is of growing interest. It can achieve an electrolyser efficiency of up to 95%, power generation efficiency of up to 65%, and hence a round-trip efficiency of around 60% at ambient pressure using products now approaching commercial availability. This project considers the development and application of this new technology to the case of ORE integration using hydrogen.

Hydrogen and alternative liquid fuels (HALF) have an essential role in the net-zero transition by providing connectivity and flexibility across the energy system. Despite advancements in the field of hydrogen research both in the physical sciences and engineering, significant barriers remain to the scalable adoption of hydrogen and alternative liquid fuel technologies, and energy services, into the UK's local and national whole system infrastructure. These are technical barriers, organisational barriers, regulatory and societal barriers, and financial barriers. There are, therefore, significant gaps between current levels of hydrogen production, transportation, storage, conversion, and usage, and the estimated requirement for achieving net-zero by 2050. To address this, our proposed research programme has four interlinked work packages. WP1 will develop forward-thinking HALF technology roadmaps. We will assess supply chain availability and security. Selected representative HALF use cases will be used to identify and quantify any opportunities, risks and dependencies within a whole systems analysis. We will also develop an overarching roadmap for HALF system integration in order to inform technology advancement, industry and business development, as well as policy making and social interventions. WP2 will improve HALF characterisation and explore urgent new perspectives on the energy transition, including those related to ensuring resilience and security while also achieving net-zero. We will contrast the energy transition delivered by real incentives/behaviour versus those projected by widely-used optimisation models. The WP provides the whole systems modelling engine of the HI-ACT Hub, with a diverse array of state-of-the-art tools to explore HALF integration. WP 3 will explore the vital coupling of data and information relating to whole system planning and operational decision support, through the creation of a cyber physical architecture (CPA). This will generate new learning on current and future opportunities and risks, from a data and information perspective, which will lead to a whole system ontology for accelerated integration of hydrogen technologies. WP 4 considers options for a future energy system with HALF from a number of perspectives. The first is to consider expert views on HALF energy futures, and the public perceptions of those views. The second perspective considers place-based options for social benefit in HALF energy futures. The third perspective is to consider regulatory and policy options which would better enable HALF futures. Embedded across the research programme is the intent to create robust tools which are investment-oriented in their analysis. A Whole Systems and Energy Systems Integration approach is needed here, in order to better understand the interconnected and interdependent nature of complex energy systems from a technical, social, environmental and economic perspective. The Hub is led by Prof Sara Walker, Director of the EPSRC National Centre for Energy Systems Integration, supported by a team of 16 academics at a range of career stages. The team have extensive experience of large energy research projects and strong networks of stakeholders across England, Wales, Scotland and Northern Ireland. They bring to the Hub major hydrogen demonstrators through support from partners involved in InTEGReL in Gateshead, ReFLEX in Orkney, and FLEXIS Demonstration in South Wales for example. We shall engage to create a vibrant, diverse, and open community that has a deeper understanding of whole systems approaches and the role of hydrogen and alternative liquid fuels within that. We shall do so in a way which embeds Equality, Diversity and Inclusion in the approach. We shall do so in a way which is a hybrid of virtual and in-person field work consultation and develop appropriate digital tools for engagement.

Hydrogen and alternative liquid fuels (HALF) have an essential role in the net-zero transition by providing connectivity and flexibility across the energy system. Despite advancements in the field of hydrogen research both in the physical sciences and engineering, significant barriers remain to the scalable adoption of hydrogen and alternative liquid fuel technologies, and energy services, into the UK's local and national whole system infrastructure. These are technical barriers, organisational barriers, regulatory and societal barriers, and financial barriers. There are, therefore, significant gaps between current levels of hydrogen production, transportation, storage, conversion, and usage, and the estimated requirement for achieving net-zero by 2050. To address this, our proposed research programme has four interlinked work packages. WP1 will develop forward-thinking HALF technology roadmaps. We will assess supply chain availability and security. Selected representative HALF use cases will be used to identify and quantify any opportunities, risks and dependencies within a whole systems analysis. We will also develop an overarching roadmap for HALF system integration in order to inform technology advancement, industry and business development, as well as policy making and social interventions. WP2 will improve HALF characterisation and explore urgent new perspectives on the energy transition, including those related to ensuring resilience and security while also achieving net-zero. We will contrast the energy transition delivered by real incentives/behaviour versus those projected by widely-used optimisation models. The WP provides the whole systems modelling engine of the HI-ACT Hub, with a diverse array of state-of-the-art tools to explore HALF integration. WP 3 will explore the vital coupling of data and information relating to whole system planning and operational decision support, through the creation of a cyber physical architecture (CPA). This will generate new learning on current and future opportunities and risks, from a data and information perspective, which will lead to a whole system ontology for accelerated integration of hydrogen technologies. WP 4 considers options for a future energy system with HALF from a number of perspectives. The first is to consider expert views on HALF energy futures, and the public perceptions of those views. The second perspective considers place-based options for social benefit in HALF energy futures. The third perspective is to consider regulatory and policy options which would better enable HALF futures. Embedded across the research programme is the intent to create robust tools which are investment-oriented in their analysis. A Whole Systems and Energy Systems Integration approach is needed here, in order to better understand the interconnected and interdependent nature of complex energy systems from a technical, social, environmental and economic perspective. The Hub is led by Prof Sara Walker, Director of the EPSRC National Centre for Energy Systems Integration, supported by a team of 16 academics at a range of career stages. The team have extensive experience of large energy research projects and strong networks of stakeholders across England, Wales, Scotland and Northern Ireland. They bring to the Hub major hydrogen demonstrators through support from partners involved in InTEGReL in Gateshead, ReFLEX in Orkney, and FLEXIS Demonstration in South Wales for example. We shall engage to create a vibrant, diverse, and open community that has a deeper understanding of whole systems approaches and the role of hydrogen and alternative liquid fuels within that. We shall do so in a way which embeds Equality, Diversity and Inclusion in the approach. We shall do so in a way which is a hybrid of virtual and in-person field work consultation and develop appropriate digital tools for engagement.