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.