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REopt Modeling Informs Design of Off-Grid Water System Under Study for Navajo Nation

A water system holding tank and windmill with solar panels.

Agricultural water production and storage using wind and solar power at the 5T-529 well site near Leupp, Arizona. Photo from Katie Guerra, U.S. Bureau of Reclamation

The Bureau of Reclamation Technical Service Center will work with NREL to apply the REopt® model to inform decisions about the design of an off-grid potable water system under consideration for the Navajo Nation.

Many tribal members living in remote areas of the Navajo Nation located in northeast Arizona rely on water hauling for their domestic water needs. Individuals must haul water for potable and nonpotable uses from localized well sources—which could be as far as 20 miles round trip—multiple times per week. Previous research conducted by the Bureau of Reclamation, the University of Arizona, and the Navajo Nation tested an off-grid water treatment system to improve the quality of the livestock water supply at the Navajo Nation well 5T-529 potable water system site. The pilot included evaluations of membrane distillation and nanofiltration, which led to the determination that nanofiltration is a more effective treatment method.

The next phase of research is to evaluate the 5T-529 site as a potential location for an off-grid potable water system to be co-located with the existing, nonpotable livestock water system. Working with the Bureau of Reclamation Technical Service Center, NREL is using REopt to model the optimal size of system components, including a photovoltaic system, battery storage, a generator, a nanofiltration membrane system, and a potable water tank. This case study will provide valuable design information for a possible potable water project at 5T-529.

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NREL technical report: Energy-Water Microgrid Opportunity Analysis at the University of Arizona's Biosphere 2 Facility

NREL Integrated Water Systems website


Bureau of Reclamation

Key Partners

Navajo Nation

University of Arizona


Dan Olis