A water-electricity nexus model to analyze thermoelectricity supply reliability under environmental regulations and economic penalties during drought events

A reliable thermoelectricity supply system requires available cooling water. Recent electricity supply failures that have occurred all over the world during drought events indicate that the thermoelectricity system is vulnerable. However, knowledge and policy gaps remain regarding water-electricity interactions at the watershed scale. In this study, a water-electricity nexus model is developed to facilitate electricity generation decisions and environmental policy designs involving cooling water consumption and temperature controls. This nexus model consists of three modules, a physically based hydrologic module, a decentralized optimization module, and a thermoelectricity generation module, which are closely integrated at the daily time step. The model is used to quantify tradeoffs between environmental impacts and potential electricity supplies at the power plant and watershed levels. A case study is conducted to demonstrate the model application for a watershed-wide, coordinated water-energy policy design under different combinations of environmental regulations and economic penalties during a drought event.