Water Resources and Western Power Production
Water has always been a major economic driver in the western United States. The power industry has not been immune from water scarcity issues, and current plants often struggle to find the fresh water needed to keep the electricity flowing.
Water availability and drought conditions, plus EIA-projected regional thermoelectric
generation growth by North American Electric Reliability Council region.
Western states experience severe to extreme drought, (1) and often the water scarcity coincides with demand for power generation. Regional thermoelectric capacity in the western U.S. is projected to increase by 41 to 165 percent by 2025, illustrating the demand on limited water resources.
Thermoelectric plants withdraw a tremendous amount of fresh water, which is used for condenser cooling, boiler make-up water, flue gas desulfurization system spray, ash transport and other plant uses. Nationally, thermoelectric plants account for 39 percent of fresh water withdrawals but only 3 percent of the consumption.(2) Thermoelectric plants withdrew for use approximately 25 gallons/kWh or nationally 136 billion gallons/day in 2000.
Thermoelectric plant consumption has been estimated at approximately 0.47 gallons/kwh(3). Approximately 99 percent of the water for thermoelectric use originates from surface waters, such as rivers and lakes. The demand for fresh water for power generation will increasingly compete with other sectors, such as agriculture, domestic and in-stream use.
Recent development activities sponsored by the U.S. DOE are focused on reducing fresh water withdrawals though alternative non-traditional cooling water sources, innovative water recovery technologies, and advanced cooling technology (hybrid air and water cooling). The focus is on makeup cooling tower water, the single largest use of fresh water at current thermoelectric plants.
Examples of technical approaches to fresh water use at thermoelectric plants include:
- Recovering water produced through the removal of moisture from western coals during upgrading.
- Removing the moisture from the flue gas after combustion as opposed to recovering the moisture from western coals prior to combustion.
- Using water from coalbed methane (CBM) production as an alternative to fresh water.
- Using the water that must be pumped to allow for the extraction of coal.
- Reducing fresh water use by incorporating air-cooled surfaces into the water-based condenser cooling systems used by the majority of thermoelectric plants in the U.S. (hybrid cooling).
Identifying alternative fresh water sources and developing technologies that reduce water demand at thermoelectric plants are essential to the West’s energy future. Increasingly, water issues are becoming eastern issues as well. WRI can be of assistance in evaluating options for the industry.
(1) “Estimated Use of Water in the United States in 2000,” USGS Circular 1268, March 2004.
(2) “Innovative Approaches and technologies for improved Power Plant Water Management,” 2004, DOE NETL FACTs
(3) Torcellini, Long and Judkoff, “Consumptive Water Use for U.S. Power Production,” 2004, ASHRAE Winter Meeting.