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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.

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.

1Historically, the focus of the agricultural industry has been increasing profit through maximizing crop yield. Costs for energy and water are small compared to equipment and personnel, and are thus often overlooked. However, energy costs for irrigation are increasing and could be exacerbated with declining water levels in many Western states. This trend has motivated many farmers to explore sustainable irrigation water and energy management practices. Much of this new focus has been directed towards the adoption of new agricultural technologies with a misplaced assumption that technology alone will inherently bring all the benefits. On one hand, farms are going through a paradigm shift, and are turning into net electricity generators, and on the other, higher penetration of intermittent renewable sources into the electricity grid, require dynamic loads to help the grid balance its intrahour variability and short duration ramps. The agricultural industry could be restructured to utilize larger amounts of renewable energy such as wind and solar and provide a great deal of flexibility to the grid. As emerging producers of clean energy, farmers are required to learn and speak the complex language of the electricity grid in order to monetize their energy generation while making the renewable electricity grid more resilient and reliable. In this paper, we develop a foundational approach for understanding and connecting three important concepts that can help the agricultural industry during this critical transition period. Those three concepts are: (a) current and future needs of the electricity grid, (b) available electricity market mechanisms through which farms can provide services to the grid, and (c) understanding electricity consuming/generating equipment on farms. Defining these concepts and condensing them into a standardized framework, can remove a significant barrier for enabling farms to provide services to the electricity grid while improving their bottom line.

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