Controls on water use for thermoelectric generation: case study Texas, US

Area of Science:

• Environmental Science
• Energy Policy
• Water Resource Management

Background:

• The U.S. heavily relies on thermoelectric (steam electric) power generation, which requires substantial water for cooling.
• Understanding water use in thermoelectric generation is crucial for managing water resources, especially in water-scarce regions.
• Texas serves as a key case study due to its significant thermoelectric power generation capacity.

Purpose of the Study:

• To quantify water consumption and withdrawal for thermoelectric generation in Texas.
• To identify the primary controls influencing water use in this sector.
• To analyze trends in water demand for thermoelectric cooling.

Main Methods:

• Utilized data from Texas in 2010 to calculate water consumption and withdrawal for thermoelectricity.
• Compared water consumption intensity (gal/kWh) across different generator technologies and cooling systems.
• Analyzed the impact of cooling system types (cooling towers vs. cooling ponds) on water withdrawals.

Main Results:

• In 2010, Texas thermoelectricity consumed approximately 0.43 million acre feet (maf) of water, representing about 4% of the state's total water consumption.
• Water withdrawals were significantly higher (26.2 maf) due to water circulation in cooling systems.
• Natural gas combined cycle generators with cooling towers exhibited a 63% lower water consumption intensity compared to traditional steam turbine generators using cooling ponds.

Conclusions:

• Generator technology (thermal efficiency) and cooling system type are key controls on water consumption and withdrawal in thermoelectric generation.
• The shift towards natural gas combined cycle plants with cooling towers has led to a significant reduction in water demand for thermoelectric cooling since 2000.
• Optimizing cooling technologies is essential for sustainable water management in the power generation sector.