Drought conditions across the Southeast have begun affecting power plant operations. According to the Associated Press, 24 of America’s 104 nuclear reactors are in areas now experiencing the most severe levels of drought, and 22 of those plants draw their cooling water from rivers and lakes. Recently, the level of several of those lakes nearly fell to the minimum necessary to continue reactor operation. Last August, for example, Tennessee Valley Authority said that higher inlet water temperatures caused by lower water levels had forced load curtailments or plant shutdowns at its Browns Ferry, Gallatin, and Cumberland plants. Reduced hydro generation has been another consequence of the drought (see “Water’s role in power generation”).
In past years, the major obstacle to new plant development was either access to transmission lines or the price and/or availability of a particular fuel. Recently, water availability became an additional hurdle, and one that looks to grow higher.
At the nexus of water and power generation are a wide variety of societal issues, policy and regulatory debate, environmental questions, technological challenges, and economic concerns. Water is emerging as a significant factor in economic development activities. Planning efforts must consider the availability and quality of water resources in a given locality or region to ensure that supplies are available to accommodate existing and future water consumers over the long term. Failure to do so can result in stunted growth, economic flight, inequitable development, and even open conflict.
Today, many plants are finding that a sustainable source of water has become a top priority. Energy-water issues have become increasingly visible in recent years. As important examples, consider passage of the Energy Policy Act of 2005; repeated introduction of the Energy-Water Efficiency and Supply Technology bill; increasingly severe regional drought conditions across the U.S.; additional difficulty siting new plants in arid regions; and further media attention to and public concern over water availability and supply.
This article discusses some of the technical, regulatory, and political issues that frame the water-electricity debate. Given the increasing perceived value of water, the generation industry’s understanding of and response to these issues will be critical to America’s future.
Demographics and tradeoffs
Drought conditions are not limited to the Southeast. A Government Accountability Office (GAO) report prepared in 2003 addressed the issue of freshwater supply at the state level. It indicated that, assuming normal rainfall conditions, the water managers of 36 states anticipated shortages in localities, regions, or even statewide over the next 10 years (2003 to 2013). The report went on to say that “drought conditions will exacerbate shortage impacts.”
The Energy Information Administration’s (EIA’s) latest forecast—its Annual Energy Outlook 2007 (AEO 2007)—estimates that U.S. thermoelectric (thermal, for short) generating capacity will grow from approximately 709 GW (net, taking into account plant retirements) in 2005 to 862 GW in 2030. Accordingly, thermal power plants will increasingly compete for freshwater with residential, commercial, agricultural, and industrial users—particularly in regions with limited freshwater supplies. In addition, current and future water-related environmental regulations will also challenge the operation of existing power plants and the permitting of new ones.
The growth in power demand will not be geographically uniform, so capacity expansion will differ by region. Regions with strong population growth (such as the Southeast and Southwest) show high growth in water consumption, while regions with minimal to modest population growth (Midwest and Mid-Atlantic states, for example) exhibit modest growth in consumption.
For example, although the EIA projects a 22% jump in installed thermal capacity on a nationwide basis by 2030, it expects a 58% increase in the West and a 30% increase in the Southeast. Significantly, both regions have among the fastest rates of population growth (Figure 2) and are already struggling to find enough supplies of freshwater to meet demand.
2. U.S. population growth trends, 1970–2030. Each block on the map represents one county. The height of each block is proportional to that county’s population density in the year 2000, so the volume of the block is proportional to the county’s total population. The color of each block shows the county’s projected change in population between 1970 and 2030, with shades of orange denoting increases and blue denoting decreases. The patterns of recent population change—growth concentrated along the coasts, in cities, and in the South and West—are expected to continue. Source: U.S. Global Change Research Program
Because supplies of freshwater are limited, its withdrawal and consumption will have to be allocated carefully by governments. These decisions have long been extremely important in many foreign countries, and they are likely to become top priorities at various levels of government in the U.S. in the near future. Like all decisions involving a limited resource, tradeoffs will be inevitable. At the end of the day, someone will have to determine which is more important: making water available for drinking and personal use, for growing food, or for producing electricity. (see "National Energy Technology Laboratory solicits water management technologies applications".)
More precious than power
In the future, developers will find it more difficult to permit new plants due to water concerns. At the same time, existing plants will experience increasing pressure to reduce their water withdrawal and consumption.
In 2006, Research and Development Solutions LLC contacted state government water monitoring agencies to ask if they limit freshwater withdrawal and/or consumption by thermal plants in their state. Of the 33 states that responded, 24% indicated that plants must either have a senior water right or purchase such a right from an entity willing to sell it. Another 18% indicated that limitations are imposed when water levels fall below a certain flow level or during water shortages. An additional 18% of states responded that water withdrawal and consumption rules vary regionally within the state; some areas have no limit, but areas that are water-sparse or over-allocated require water rights or special permits. The number of states with over-allocated water resources is expected to increase over time.
Concerns about water supply expressed by state regulators, local decision-makers, and the general public are already affecting power projects across the U.S. For example:
- In March 2006, an Idaho House committee unanimously approved a two-year moratorium on construction of coal-fired power plants in the state based on environmental and water supply concerns.
- Arizona rejected the permit application for a proposed power plant because of concerns about how much water the plant would withdraw from a local aquifer.
- A coal-fired power plant under construction in Wisconsin on Lake Michigan has been under attack from environmental groups for the potential negative impacts of the facility’s cooling water–intake structures on aquatic life.
- In February 2006, Diné Power Authority agreed to pay the Navajo Nation $1,000 per acre-foot of water needed for the proposed Desert Rock Energy Project.
- In an article discussing a proposed 1,200-MW plant in Nevada, opponents of the plant stated, “There’s no way Washoe County has the luxury anymore to have a fossil-fuel plant site in the county with the water issues we now have. It’s too important for the county’s economic health to allow water to be blown up in the air in a cooling tower.”
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