Valuing feedback mechanisms between water and energy systems in hydropower networks

Multi-sector modelling frameworks are fundamental platforms for exploring the complex interactions between the water and energy sectors. While acknowledging the pivotal role of hydropower within the energy system, it is essential to understand the feedback mechanisms between power and water systems to guide the design of hydropower operations and enhance water-energy management strategies. With this in mind, we developed a modelling framework hinged on a bidirectional coupling between water and power system models. We simulate the constraints imposed by water availability on grid operations as well as the feedback between the state of the energy and water systems. For example, the framework explicitly accounts for conditions of hydropower oversupply, during which part of the water could be stored in reservoirs or allocated to other sectors. The flexibility added to the system gives operators control over desired reservoirs, and allows the system to exploit the benefits warranted by a more efficient use of renewable energy. We evaluate the framework on a real-world case study based on the Cambodian grid, which relies on hydro, solar, and thermoelectric resources. In our analysis, we demonstrate that managing hydropower reservoirs with the feedback mechanism in mind allows us to improve system’s performance—evaluated in terms of power production costs and CO₂ emissions. Overall, our work contributes a novel modelling tool for climate-water-energy nexus studies, working towards an optimal integration of hydropower and other renewable energy sources into power systems.