Energy-Water Nexus: Potential Energy Savings and Implications for Sustainable Integrated Water Management in Urban Areas from Rainwater Harvesting and Gray-Water Reuse
Publication: Journal of Water Resources Planning and Management
Volume 141, Issue 12
Abstract
Saving water saves energy. Consequently, implementing integrated water management (IWM) measures that reduce potable water consumption, stormwater runoff, and wastewater generation can potentially translate into significant energy savings. In this paper, the energy savings associated with IWM measures of rainwater harvesting and gray-water reuse are estimated, both at national and local utility scales using published data. At the national scale, it is estimated in this paper that up to and $270 million can potentially be saved annually by replacing landscape irrigation and other outdoor water uses through rainwater harvesting alone, and up to and $950 million in combination with gray-water reuse. Similarly, in Charlotte, North Carolina, the local water utility can potentially save up to and $1.8 million annually. However, annual energy and associated cost savings per household are low at either scale, ranging between 1 and 120 kWh with associated cost savings of less than $10. These results are discussed in terms of energy savings’ role in IWM policy considerations and promotion of sustainable water use in urban areas.
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Acknowledgments
The authors would like to thank Jacqueline A. Jarrell, Professional Engineer (Superintendent, Environmental Management Division), Travis Hunnicutt, and William Rice of the Charlotte–Mecklenburg Utility Department for their assistance and for providing CMUD energy intensity and electricity cost data for the research reported in this paper.
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Journal of Water Resources Planning and Management
Volume 141 • Issue 12 • December 2015
Copyright
© 2015 American Society of Civil Engineers.
History
Received: Jun 13, 2014
Accepted: Jan 29, 2015
Published online: Apr 10, 2015
Discussion open until: Sep 10, 2015
Published in print: Dec 1, 2015
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