The Ocean-REFuel project brings together a multidisciplinary, world-leading team of researchers to consider at a fundamental level a whole-energy system to maximise ocean renewable energy (Offshore wind and Marine Renewable Energy) potential for conversion to zero carbon fuels. The project has transformative ambition addressing a number of big questions concerning our Energy future: How to maximise ocean energy potential in a safe, affordable, sustainable and environmentally sensitive manner? How to alleviate the intermittency of the ocean renewable energy resource? How ocean renewable energy can support renewable heat, industrial and transport demands through vectors other than electricity? How ocean renewable energy can support local, national and international whole energy systems? Ocean-REFuel is a large project integrating upstream, transportation and storage to end use cases which will over an extended period of time address these questions in an innovative manner developing an understanding of the multiple criteria involved and their interactions.

A reliable water supply and a successful energy transition are two necessary conditions for a sustainable future. Yet we know little about how the switch to intermittent renewables (wind, solar) for our energy supply will affect the operation of our water infrastructure. The time for planning for this is now: unpreparedness in the face of energy supply fluctuations has wide-ranging economic impacts, as demonstrated by the developing energy crisis (as of January 2022). The dual aim of this New Investigator Award proposal is to develop a fast water-energy simulator to quantify the impacts of a decarbonised nationwide power grid on water resource systems, and to demonstrate its integration into state-of-the-art strategic water resource planning. This simulator will be the first to enable the exploration of the joint dynamics of water resource systems and low carbon energy systems at timescales ranging from hourly to multi-annual. This project will also promote an improved understanding of flexibility as an opportunity to adapt to a decarbonised grid as well as to buffer against drought. To achieve its aims, the project will address the following challenges: (C1) How can we represent the variability of weather-dependent inputs (wind, solar irradiation, rainfall) and their consequences in coupled water-energy systems? Weather evolves at fine timescales (e.g., hourly) and low precipitations can threaten water supply over a few years. Representing how these timescales interact, while including the national power grid, is a challenge that has yet to be tackle by academic research. To tackle this, the project will implement a fast hourly water-energy system simulator including the national electricity grid, both to assess energy transition impacts on water systems and measure first-order benefits of using the built-in flexibility of water systems to manage energy demand. (C2) How can we identify decision-relevant scenarios across the full range of uncertainty created by climate change, population growth and the energy transition? This project will use the coupled simulator to explore potential climate-energy-population futures and address this question, for the first time integrating energy transition scenarios into water planning. (C3) How can we integrate the transition to a low-carbon grid into strategic water resource planning? This project will achieve that, first on a single piece of water-energy infrastructure (e.g., desalination plant connected both to local renewable energy and to the grid), then at the scale of a regional water system supplying several million users in the East of England. This project will help the water sector (companies and regulators) plan for the triple challenge of climate change, population growth, and the energy transition, and deliver a reliable water supply at affordable rates for water users.

Aviation is arguably one of the most difficult sectors to be decarbonised. The UK government's recent Transport Decarbonisation Plan targets for Accelerating Aviation Decarbonisation to reach net zero by 2050, aiming to decarbonise emissions from airport operations in England by 2040, and to support the development of new and zero carbon UK aircraft technology [1]. The Department for Transport's Aviation Strategy recommends electrification as a possible solution to mitigate aviation's carbon emissions [2]. Electrification technologies are being deployed successfully in land-based transport. Electrification is now being challenged to address the more ambitious aviation decarbonisation. In the air, electric and hybrid aircraft particularly for short-haul or regional electric aircraft have advanced rapidly. On the ground, UK airports (Heathrow as a project partner of this proposal) lead pilot decarbonisation projects to enable the transition to regional electric and sustainable aviation, and shape the landscape of future low-carbon infrastructure and services. Currently, there is a significant disconnect between power systems and electrified air transport in terms of energy users and suppliers, infrastructure and interoperability to achieve the net-zero in both industries. The electrification of aviation will create a new nexus between power systems and electrified air transport. There are several key challenges: 1) The power systems will require electrified aviation to integrate into ground energy infrastructure and must not overload the future grid. 2) Electrified aviation as a new energy user requires the power systems to supply large volumes of low-carbon electricity to meet new loads of electric aircraft. 3) Significant charging infrastructures are required. Our feasibility study on a UK airport indicates that even if only 10% domestic flights are electrified then £50M will need to be spent on charging infrastructure. 4) Significantly high costs will be incurred for building additional power generation capacity. Our initial study indicates 15 GW additional power generation capacity will be required if 45% of UK domestic flights are electrified. This proposed research will explore the fundamental integration of a new nexus between power system and electrified air transport system, named 'Aviation-to-Grid', with an ambitious aim to bridge the significant disconnect between two systems in terms of energy demand and supply, infrastructure and interoperability. This will be achieved by using the multiscale energy modelling and system integration as key research methods. A new concept of Aviation-to-Grid flexibility will be investigated as a potential solution to unlock the flexibility provisions from Aviation-to-Grid, so that infrastructure and operation costs can be reduced and co-optimised across both systems. This project, for the first time, brings power industry (National Grid ESO), airport operators (Heathrow Airport), energy infrastructure solutions (UK Power Networks Services), transport policy (Department for Transport) and the UK academic communities (Supergen, DTE Network) together in a truly interdisciplinary manner. In this project, multiscale energy modelling (WP1) and multiscale system integration (WP2) will explore a bottom-up approach across the new nexus of power systems and electrified air transport. Aviation-to-Grid flexibility provisions will be evaluated with cost-benefit analysis (WP3). Industrial application potential of Aviation-to-Grid flexibility will be demonstrated in a real-time simulation platform in the lab using representative case studies with recommendations for implementation (WP4). [1] Decarbonising transport: a better, greener Britain, Department for Transport, 14 July 2021 [2] Aviation 2050 - the future of UK aviation, Department for Transport, 22 October 2019