Product Abstract

EPRI has identified water resource sustainability and its relation to electric power as one of the key challenges within EPRI's Electricity Technology Roadmap. This report presents an overview of present and future freshwater availability and generation demand for fresh water in the United States. The report takes a first step toward development of a comprehensive framework for evaluating possible impacts of water supply limitations on electric power generation and management approaches to limiting these impacts. Information provided will be of particular value to power generation and delivery managers and planners, as well as government energy and water resource managers and regulators.

Background

Several years ago, EPRI identified water availability as major factor influencing future power development both nationally and internationally. As a result, EPRI developed a water sustainability module for the EPRI Electricity Technology Roadmap. At the same time, with the support of members in the Total Maximum Daily Load (TMDL), Watershed and Ecosystem Issues Program, EPRI initiated research to develop a comprehensive framework to evaluate potential power industry susceptibility to water availability shortages.

Objective

• To survey present and future freshwater availability and generation demand for freshwater in the United States.

• To initiate development of a comprehensive framework for evaluating possible impacts of water supply limitations on electric power generation and management approaches to limiting such impacts.

Approach

Investigators computed and mapped various metrics characterizing water use. Based on these metrics, they calculated and mapped two composite indices—a Water Supply Sustainability Index and a Thermoelectric Cooling Constraint Index. The first index identifies regions of the country where water sustainability concerns are likely to be most severe, while the second identifies regions where constraints on cooling water withdrawals for power generation are expected to be significant. These indices can be used to identify areas for more detailed analysis. A case study for the Phoenix, Arizona area is included in this report.

Results

Based on the metrics used and indices calculated, areas vulnerable to water availability shortages and water-induced constraints on electric power generation are not limited to the arid and semi-arid West and Southwest, but occur throughout the United States. Vulnerability will increase over the next quarter of a century as a result of greater demands for fresh water associated with population growth. Climate change and growing concerns about environmental protection may also exacerbate the situation.

Although the maps of water sustainability created for this study use the best available information today, there is a need for improved data, particularly in the following areas: 1) instream flow requirements for ecological protection; 2) water (reservoir and groundwater) storage and withdrawal capacity; and 3) fine temporal resolution of water use. From the standpoint of thermoelectric generation, the study finds that many power plants will need to be located in areas facing water shortages and will thus require comprehensive evaluation of the tradeoffs in using less or no water.

EPRI Perspective

EPRI's Electricity Technology Roadmap provides a long-term (20-50 year) global vision for a robust and environmentally sustainable energy future. Societal and economic health are highly dependent on the availability of electric power, while electric power generation and delivery are, in turn, highly dependent on the availability of water. To address the challenge of energy/water sustainability, EPRI has created a Water Sustainability Initiative and has incorporated water sustainability research into its base research program within the Water and Ecosystems Area. EPRI is working cooperatively with the U.S. Department of Energy (USDOE) and USDOE national laboratories to create a national research program that will address the energy/water nexus. In partnership with Public Service Company of New Mexico and Los Alamos National Laboratory, EPRI has created the ZeroNet Water-Energy Research Initiative, a comprehensive integrated research program, to meet New Mexico's increasing electric power demand without increasing net fresh water withdrawals for power plant cooling. Finally, EPRI is working with the California Energy Commission and Lawrence Livermore National Laboratory to organize a workshop to identify major energy/water sustainability issues in California.