Spatially optimized water-energy system design considers regional and sectoral benefit distribution

Historically, the design of and investment in water and energy systems has been undertaken independently or considering simplified interlinkages. This approach misses opportunities for synergies between the systems' use of resources and is more likely to cause inefficiencies and conflict between sectoral or regional stakeholders. In this study, we develop a framework to couple integrated water-energy simulators with multi-objective heuristic optimisation under uncertainty. We explore the benefits of optimizing the design of water-energy systems considering their regional and sectoral interdependencies. A synthetic case study aims for water-energy infrastructure system design that considers sectoral dependencies in resource allocation, operation of multi-purpose reservoirs and spatially distributed water and energy demands and assets, which include irrigation demands and water and energy demands in cities, irrigation canals, transmission lines, thermal power plants, and hydropower plants. Different regionally aggregated and disaggregated multi-objective optimization formulations are compared. Aggregated formulations arbitrarily induce unintended biases in the regional distribution of benefits, whilst spatially disaggregated metrics enable addressing regional benefit distribution explicitly. The case-study is used to demonstrate the value of identifying regionally and sectorally acceptable designs. The approach is intended for multi-community systems where diverse stakeholder groups are mindful of their share of development benefits.