City-scale analysis of water-related energy identifies more cost-effective solutions

•We developed cost curves for water-related energy (WRE) saving in urban water systems.•Higher end use WRE saving potential implies broadening the current scope of cost curves.•Some end-use options are more favourable than utility options with similar CAPEX.•Hot water related options have the most cost-effective urban WRE saving potential.•We demonstrated the use of cost curves to compare utility and end-use options consistently.