Decarbonising Water Networks: Optimised Scheduling of Time-Sensitive Loads in the Presence of Cost-based Solar PV Systems

Renewable Energy Systems (RESs) based on Third-Party Finance models such as Power Purchase Agreements (PPAs), are an economically and environmentally viable option for Water Distribution Networks (WDNs) aiming to transition towards a Net Zero future. However, optimizing the scheduling of time-sensitive Water Treatment loads in the Water Treatment process becomes challenging in the presence of two power sources with varying dynamic pricing structures. Furthermore, limited work has been carried out in the area of Demand Response (DR) techniques for WDNs. This study proposes a universal optimal load scheduling strategy for Water Distribution Networks (WDNs), designed to optimise the operation of time-sensitive loads across diverse water systems. A seasonal case study focusing on a water treatment facility in the northeast of the UK demonstrates the application of the proposed DR approach using a Mixed Integer Linear Programming (MILP) based optimisation framework that incorporates a PV system with a dynamic cost structure, while also prioritising it as the main power source over the grid to promote the decarbonisation of the WDN. The results demonstrate that the proposed approach effectively schedules energy-intensive, time-sensitive loads, saving up to 53.7 kgCO2 in carbon emissions and up to 59.180% in energy costs in an average summer week, compared to only using electricity from the utility grid, thereby contributing to the sustainable operation of WDNs.