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Averting 22 Water-Electricity Crises in the United States
27 Jul, 2009 09:29 pm
Conventional power plants could create severe water shortages in 22 metropolitan areas by 2025.
In the United States, nuclear plants use the most water at about 43 gallons of water for every kilowatt-hour (kWh) generated. Coal and waste-incineration plants use about 36 gallons of water for every kWh generated. Natural gas plants use about 14 gallons of water for every kWh generated. The industry average is 25 gallons of water for every kWh generated, or 0.5 gallons consumed and 24.5 withdrawn per kWh.
The numbers quickly aggregate into astronomical amounts of water. Relying on industry averages to assess likely water use, coal-fired power stations generated 1957 billion kWh in 2006, meaning that they used almost 58 trillion gallons of water. Nuclear facilities generated 787 billion kWh and used about 34 trillion gallons. Natural gas plants produced an additional 877 billion kWh and consequently used slightly more than 12 trillion gallons.
These numbers mean that on average thermoelectric power plants use more water than the entire country’s agricultural and horticultural industry, which cover the nation’s irrigation, frost protection, field preparation, cropping, self-supplied landscaping, and maintenance of golf courses, parks, nurseries, cemeteries, and landscaping needs. To put these differing numbers in perspective, Americans use about three times as much water turning on their lights and running appliances than for taking showers and watering lawns.
The water needs for expected future thermoelectric power plants, if they continue to use twenty-five gallons of water per kWh as they do today, in 22 metropolitan areas are so immense they could deplete the water available for other uses or, conversely, lack of water could force power plants to shut down or operate at partial capacity.
The support for such a claim comes from data related to three separate trends:
· Rates of population growth in the contiguous United States from 1995 to 2025 per square mile;
· Utility estimates of future planned capacity additions in the contiguous United States in 2025;
· Scientific estimates of the anticipated “summer water deficit,” or the difference between water supply and demand during July, August, and September, in inches of water for the contiguous United States in 2025.
An analysis of these three trends at the county level shows that every state in the country is home to at least one county that will face rapid population growth, large additions in thermoelectric power plant capacity, or expected shortages of water in the summer. Yet while thousands of counties were at risk of either rapid population growth, significant increases in thermoelectric capacity, or the increased likelihood of summer water deficits, and hundreds were at risk from two out of the three, 22 counties were most at risk from all three at once. In these 22 areas, water development needed to satisfy increased population growth could tradeoff severely with the water needed for new power plants. These areas will have a combined population growth of at least 500 people per square mile, electricity demand for at least 2,700 MW of thermoelectric capacity, and a summer water deficit of at least 1.5 inches by 2025.
These areas are, in order of projected water shortage in 2025:
1. Mecklenburg County in North Carolina, home to the metropolitan area of Charlotte;
2. Lake County in Illinois, home to the metropolitan area of Chicago;
3. Will County in Illinois, home to the metropolitan area of Chicago;
4. Queens County in New York, home to the metropolitan area of New York City;
5. Cobb County in Georgia, home to the metropolitan area of Atlanta;
6. Dallas County in Texas, home to the metropolitan area of Dallas;
7. Coweta County in Georgia, home to the metropolitan area of Atlanta;
8. Denver County in Colorado, home to the metropolitan area of Denver;
9. Montgomery County in Maryland, home to the metropolitan areas of Baltimore and Washington, DC;
10. St. Charles County in Missouri, home to the metropolitan area of St. Louis;
11. Washington County in Minnesota, home to the metropolitan area of St. Paul;
12. Bexar County in Texas, home to the metropolitan area of San Antonio;
13. Calvert County in Maryland, home to the metropolitan areas of Baltimore and Washington, DC;
14. Harris County in Texas, home to the metropolitan area of Houston;
15. Tarrant County in Texas, home to the metropolitan area of Dallas;
16. Multnomah County in Oregon, home to the metropolitan area of Portland;
17. Contra Costa County in California, home to the metropolitan area of San Francisco;
18. Fort Bend County in Texas, home to the metropolitan area of Houston;
19. Wake County in North Carolina, home to the metropolitan area of Raleigh;
20. Suffolk County in Massachusetts, home to the metropolitan area of Boston;
21. Clark County in Nevada, home to the metropolitan area of Las Vegas;
22. Montgomery County in Texas, home to the metropolitan area of Houston.
Business as usual within these metropolitan could induce direct tradeoffs between the water needed to cool new power plants and the water needed for drinking, irrigation, fisheries, and agriculture.
Twenty-two regions of the country will be most at risk if current trends continue, yet the scope and nature of the challenges facing each of these areas are distinct. To list just a few examples, for Houston new power plants would likely continue to use water from the Trinity, San Leon, and San Jacinto rivers and reservoirs, depleting the water available for drinking and possibly interfering with the water needed for irrigation and agriculture.
In Atlanta, new thermoelectric power plants would deplete the water recharging Lake Lanier in Georgia, reducing available supply for commercial and industrial users in the region and complicating water management downstream in Alabama and Florida.
To supply Las Vegas, new thermoelectric power plants would have to take water from Lake Mead, exacerbating an already existing drought and reducing the water needed to irrigate Southwestern California and Mexico.
In New York, new thermoelectric power plants would risk impinging and entraining millions of fish, with deleterious impacts on local fisheries and riparian ecosystems.
The impending water associated challenges with thermoelectric power plants serve an important reminder that climate change is not the only serious environmental issue facing the electricity industry or the energy sector. To be sure, the two are connected—especially as climate change induces changes in precipitation patterns and influences the frequency and severity of floods and drought—but the water-electricity challenge is serious in its own right, and deserving of swift and decisive policy intervention.
This intervention should include ramping up R&D projects on advanced thermoelectric cooling cycles, possibly banning the construction of new water-intensive power plants, altering power plant permitting procedures, promoting energy efficiency and demand-side management, and relying more on wind and solar power plants to produce electricity.
For further reading:
Benjamin K. Sovacool and Kelly E. Sovacool, “Preventing National Electricity-Water Crisis Areas in the United States,” Columbia Journal of Environmental Law 34(2) (July, 2009), pp. 333-393, available at http://www.columbiaenvironmentallaw.org/articles/preventing-national-electricity-water-crisis-areas-in-the-united-states.
Benjamin K. Sovacool, “Running on Empty: The Electricity-Water Nexus and the U.S. Electric Utility Sector,” Energy Law Journal 30(1) (April, 2009), pp. 11-51, available at http://www.eba-net.org/docs/elj301/11_-_sovacool.pdf
Benjamin K. Sovacool and Kelly E. Sovacool, “Identifying Future Electricity Water Tradeoffs in the United States,” Energy Policy 37(7) (July, 2009), pp. 2763-2773, available at http://linkinghub.elsevier.com/retrieve/pii/S0301421509001645