Power and Water At Risk (2011)
Across the United States, our demand for electricity is colliding with our need for healthy and abundant freshwater.
Our electricity system’s dependence on water runs deep.
Water’s role in hydropower—and the risks to hydroelectric generation when water is unavailable—are clear.
But large steam-generating power plants (particularly the fossil-fuel- and nuclear-powered plants that produce the lion’s share of our electricity) also rely—often heavily—on water for cooling purposes.
Water resources, however, are under increasing pressure and in some instances have been unable to meet power plant cooling needs.
As our demand for electricity continues to rise, the water dependence of many power plants puts the electricity sector, water resources, and other water users at growing risk.
Power plant water dependence threatens the availability and quality of our water.
Cooling power plants requires the single largest share of U.S. freshwater withdrawals: 41 percent. This water dependence threatens both the availability and the quality of our water resources.
Power plant water withdrawals and related water consumption can have significant impacts on local water availability for other users and for aquatic ecosystems.
Withdrawals can also harm wildlife such as fish, turtles, and other aquatic species that are sucked into or trapped by intake mechanisms.
As for water quality, coal and nuclear plants discharge water in the summer at an average temperature 17°F warmer than when it entered the plant.
This warmer water can harm wildlife, as can chemicals such as chlorine, bromine, and biocides that may be introduced into the water during plant operations.
The water use habits of power plants pose risks to water sources, other users, and power plants themselves.
When adequate cooling water is not available to fossil fuel, nuclear, and other steam-generating plants due, for example, to prolonged drought or high water temperatures caused by a heat wave, the plants have to cut back power production or even shut down.
The Southwest and Southeast are particularly at risk for these types of water-energy collisions.
Hydropower facilities face the same fate when water levels drop too low for power production.
Even when power plants get the water they need in times of water stress or scarcity, their continued operation may come at a cost to others who rely on the same water.
The potential for this kind of collision between water users will grow wherever the demand for both energy and water increases—and will be exacerbated in some regions by global warming.
This is no futuristic scenario—these risks exist across the country, collisions are happening now, and the impacts are being felt by the power sector, its customers, and other water users.
Power and Water At Risk describes characteristic ways in which energy-water collisions occur in each region of the country. We also highlight power companies and energy developers making choices that reduce water dependencies—and thus, water-related risks and impacts.
Smarter energy decisions can greatly reduce the pressure our demand for electricity places on water resources.
The U.S. electric sector’s heavy water dependence represents an opportunity.
Smarter energy decisions can greatly reduce the pressure that our demand for electricity places on increasingly stressed water resources, and help us improve the resilience of our electricity infrastructure.
By embracing lower-water technologies such as air cooling for power plants, or no-water options such as wind farms and energy efficiency, we can reduce water-related impacts while avoiding or minimizing the risk of costly water-related power disruptions.