The scarcity of fresh water is holding up the proposed 3000 MW Blue Castle nuclear plant in Utah.
"In the United States, power generation consumes 20 percent of the water
not used by agriculture. ... Gas-fired plants consume the least water per unit of energy produced;
coal- and oil-fired plants consume twice as much water as a gas-fired
plant; and nuclear plants consume three times as much as a gas-fired
plant." Quotes are from this report. Chemical capture of CO2 (amine scrubbing) is profoundly non-feasible for several reasons, including that it would double the water consumption of "clean coal" plants.
"Consume" means that the water is gone and no longer available for other uses. That's the figure that counts. "Withdrawal" is something different, where the water is used for cooling and then returned heated to the environment.
Water withdrawals for open-loop wet cooling (once-through) are being shut down over concerns over thermal pollution and fish fatalities. The Indian Point nuclear plant is an example. So power plants will have to find some better way than conventional closed-loop wet cooling to condense the turbine exhaust steam.
We need to reduce the amount of water wasted into the atmosphere from thermal power plants. Any ideas? Mine will be published as US Patent 7,987,677 on Aug. 2, 2011.