Reducing water freshwater consumption at coal-fired power plants : approaches used outside the United States.

Coal-fired power plants consume huge quantities of water, and in some water-stressed areas, power plants compete with other users for limited supplies. Extensive use of coal to generate electricity is projected to continue for many years. Faced with increasing power demands and questionable future supplies, industries and governments are seeking ways to reduce freshwater consumption at coal-fired power plants. As the United States investigates various freshwater savings approaches (e.g., the use of alternative water sources), other countries are also researching and implementing approaches to address similar - and in many cases, more challenging - water supply and demand issues. Information about these non-U.S. approaches can be used to help direct near- and mid-term water-consumption research and development (RD using more efficient coal-fired technologies such as cogeneration, IGCC, and direct firing of gas turbines with coal; replacing or retrofitting existing inefficient plants to make them more efficient; installing high-performance monitoring and process controls; and coal drying. The motivations for increasing power plant efficiency outside the United States (and indirectly reducing water consumption) include the following: (1) countries that agreed to reduce carbon emissions (by ratifying the Kyoto protocol) find that one of the most effective ways to do so is to improve plant efficiency; (2) countries that import fuel (e.g., Japan) need highly efficient plants to compensate for higher coal costs; (3) countries with particularly large and growing energy demands, such as China and India, need large, efficient plants; (4) countries with large supplies of low-rank coals, such as Germany, need efficient processes to use such low-energy coals. Some countries have policies that encourage or mandate reduced water consumption - either directly or indirectly. For example, the European Union encourages increased efficiency through its cogeneration directive, which requires member states to assess their national potential for cogeneration, analyze barriers to achieving the potential, and then establish support schemes to achieve the potential. China's Eleventh Five-Year Plan (2006-2010) has an energy strategy that specifies, among other things, that production should be optimized by promoting the development of large-scale, high-efficiency units, and that air-cooled technologies should be used in areas with water shortages. The United States lacks many of these drivers. There are no government requirements that mandate more efficient plants. The United States has ample supplies of relatively cheap coal, and U.S. water-short areas are not as extensive as in countries such as China, South Africa, and Australia. Often, other countries have deployed water-savings technologies to a greater degree than the United States.