Estimating Freshwater Needs to Meet Future Thermoelectric Generation Requirements. 2008 Update

摘要

The purpose of this report is to estimate future freshwater needs for thermoelectric power generation. Thermoelectric power plants--coal, oil, natural gas, and nuclear fueled power generators using a steam turbine based on the Rankine thermodynamic cycle require significant quantities of water for generating electrical energy. For example, a 500 MW coal-fired power plant uses over 12 million gallons per hour of water for cooling steam turbine exhaust. The water required for thermoelectric plants is withdrawn primarily from large volume sources, such as lakes, rivers, oceans, and underground aquifers. While both freshwater (approximately 70%) and saline water (approximately 30%) are currently used for thermoelectric generation, this report focuses on freshwater because freshwater sources are becoming increasingly strained. Water consumption is used to describe the loss of that water, typically through evaporation into the air.