New Mexico Coalition for Clean Affordable Energy
Water Impacts of Conventional Generation
Conventional water-cooled coal-fired electricity generation uses approximately 15-20 acre-feet of water per megawatt. The best combined cycle natural gas generation uses about 7 acre-feet of water per megawatt annually (if run continuously). Single cycle natural gas generation, which is generally only used for small peaking plants (under a hundred megawatts, say), use very little water - about 1/3 acre foot per megawatt per year (if run continuously, which is rarely the case for peaking plants).
Water use by existing power plants in New Mexico is approximately 63,000 acre feet of water per year (one acre foot equals 325,851 gallons!), most of which is simply evaporated and therefore completely lost, is about half the total annual water use of Albuquerque! Here are some 1995 figures for water use by various existing or planned New Mexico power plants:
| Plant | Generation capacity in megawatts |
Annual water use in acre-feet |
|---|---|---|
| San Juan | 1600 | 19,000 |
| Four Corners | 2250 | 35,000 |
| Escalante | 250 | 3150 |
| Proposed Duke Plant near Deming | 560 | 4000 |
Water for cooling is not the only way that power plants degrade water supplies. Water is also sometimes used for simply moving coal. For example, Peabody Coal uses millions of gallons of water a day to move coal from Hopi Land to Nevada.
