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PrefaceReducing energy consumption through investment in advanced technologies and practices can enhance American manufacturing competitiveness. Energy bandwidth studies of U.S. manufacturing sectors serve as general data references to help stakeholders understand the range (or bandwidth) of potential energy savings opportunities. The U.S. Department of Energy's (DOE) Advanced Manufacturing Office (AMO) has commissioned a series of bandwidth studies to analyze energy-intensive processes and provide technology-based estimates of potential energy savings opportunities. Most recently, AMO has commissioned a bandwidth study to analyze the energy consumption characteristics of desalination systems for municipal water. The research will determine the energy consumption and carbon emissions implications of increasing the share of potable water in the United States provided by seawater desalination. The consistent methodology used in the previous bandwidth studies has provided a framework to evaluate and compare energy savings potentials within and across manufacturing sectors at the macroscale and will now be applied to the technology study area of desalination systems. The Energy-Water Bandwidth Study of Desalination Systems will expand the scope of previous bandwidth studies by also evaluating the carbon dioxide (CO2) intensity and reduction opportunities and will inform a techno-economic analysis of desalination systems.The complete information for this study will be provided in two volumes: Volume 1: Survey of Available Information in Support of the Energy-Water Bandwidth Study of Desalination Systems (this report) reviews the parameters that impact energy, emissions, and cost considerations, and provides background research and a framework for Volume 2: Energy-Water Bandwidth Study of Desalination Systems. Table P-1 shows the specific contents of the two volumes. With growing interest of desalination to meet domestic and global potable water demands, available results should be distributed as soon as they are developed; hence, Volume 1 is published in advance of Volume 2, and serves as an interim report for the Energy-Water Bandwidth Study of Desalination Systems.

The potential impact of water shortages on U.S. manufacturing is unknown. While water for manufacturing constitutes an estimated 6% of U.S. water intake, the data (i.e., location, quantity, and purpose of water intake) needed to determine this impact does not exist. This paper will identify manufacturing subsectors at risk of physical water shortages by applying a method for estimating U.S. manufacturing water intake at the necessary spatial and sectoral resolutions. First, the data requirements to quantify a manufacturing facility’s water footprint within the context of the watershed are developed. Second, using international data, water intake at the national, state, and county-levels by each U.S. manufacturing subsector is estimated. Third, manufacturing subsectors that are most vulnerable to risks of physical water shortages are identified. Based on the results, the Paper, Primary Metals, Chemical, Petroleum and Coal Products, and Food subsectors have the largest intake, respectively. However, the Primary Metals, Fabricated Metals, Transportation Equipment, Petroleum and Coal Products, and Plastics and Rubber subsectors are at the greatest risk of physical water shortages based on concentrations of water intake in water-stressed regions. The results can be used to develop strategies to mitigate the risks of water shortages on the U.S. manufacturing sector.

In order for greater adoption to occur, existing barriers need to be mitigated. One of these barriers is the energy consumption of seawater desalination. This paper reviews the existing energy requirements for membrane and thermal-based seawater desalination systems to produce potable water. Through literature review, it identifies the commercially-available option with the lowest energy intensity and the thermodynamic minimum energy requirement for each unit operation of the system. The paper then estimates the energy requirements to expand seawater desalination capacity to meet the potable water needs of water-stressed regions in the U.S. The results show that supplying 10% of the potable water demand for these regions located within 250 miles of a coastline using the lowest energy-intensity seawater desalination system commercially available would require < 0.1% of 2018 U.S. electricity consumption. This increases to approximately 0.5% if all public water for these same regions is supplied via desalinated seawater. These estimates of the energy implications of broader adoption provide an initial comparison to current U.S. electricity consumption.

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