Dias, Luís P.Seixas, Júlia2026-05-182026-05-182026-042213-1388PURE: 162748908PURE UUID: 93b97775-b118-45d7-9a45-c1f8f68c757fScopus: 105032731505WOS: 001727014400001ORCID: /0000-0003-0355-0465/work/215055652http://hdl.handle.net/10362/203181Publisher Copyright: © 2026 The Author(s).Water and energy services are key for cities’ healthy development, but their integrated management has been limited. Cities decarbonization requires fully integration of water and energy systems to prevent policies and solutions with limited benefits or even with negative trade-offs. Municipal water-system (i.e. water supply, consumption and wastewater) was integrated into the energy-system optimization model (TIMES_CityWE) to get explicitly connected water and energy flows and technologies. Optimal water-energy system configurations to deliver water and energy services for Cascais municipality in Portugal were generated up to 2050, with the goal to assess if and how net-zero carbon target and resources’ prices may act as enablers of local resources cost-effectiveness. Net-zero goal leads to efficient technologies, delivering 16% less water and 20% less energy consumed in the residential sector in 2045, compared with the absence of net-zero target. Notably, water efficient technologies show cost-effectiveness to reduce both water and energy consumption, while enhance resource self-sufficiency. Achieving net-zero carbon in 2045 requires a reconfiguration of the current energy system with 33% of the total final energy demand and 26% of water demand fulfilled by local sources, a significant increase from 2015 (6% and 13% respectively), clearly demonstrating net-zero carbon targets serve as enablers of water and energy self-sufficiency. Integrated water and energy systems modelling captures combined positive effects to optimize future configurations, providing support to better local policies.124563912engCity decarbonizationNet-zeroTIMES modellingWater-energy nexusRenewable Energy, Sustainability and the EnvironmentEnergy Engineering and Power TechnologySDG 6 - Clean Water and SanitationSDG 7 - Affordable and Clean Energyjournal article10.1016/j.seta.2026.104930https://www.scopus.com/pages/publications/105032731505https://www.webofscience.com/wos/woscc/full-record/WOS:001727014400001