Solar Desalination 

Using DistillationS&T Proposal No. 4850

Mitch HawsWater Agreements PlannerProgram Development DivisionPhoenix Area Office623‐773‐6274mhaws@usbr.gov

Solar Desalination 

Using Distillation

Mitch HawsProject ManagerWater Agreements PlannerProgram Development DivisionPhoenix Area Office623-773-6274mhaws@usbr.gov

August 28, 2015San Diego, CA USA

Research Questions• Are there opportunities to use renewable energy and

advanced water treatment systems to develop water sources which are currently unusable, such as high TDS or of marginal quality?

• Are there opportunities to “package” solar photovoltaic and thermal energy systems to provide electricity and heat to support advanced water treatment systems?

• Can renewable energy and advance water treatment systems be combined to meet a substantial part of the water and energy budget for a regional demand where limited or no access to conventional water and power systems exist?

Membrane Distillation

SW Navajo Rural Water StudyPROBLEMS

• 30% of population haul potable water and they haul fuel for electrical power demand

• Little access to conventional water supply and power grid

• Economically depressed region• Water haulers pay an estimated 15 times

more for their water and power services.• Water users are accessing impaired water• Persistent drought in the study area has

reduced available water supplies

Solar Desalination Pilot Project

Solar Desalination Flow Schematic

INTRODUCTIONThe Navajo Nation’s low population density coupled with water scarcity and water impairment makes access toadequate water supply a daunting challenge. A large portion of the population relies primarily on groundwaterwhich is often in deep aquifers and of brackish quality. Consequently, a large fraction of the population haulswater from remote wells at high costs. In addition, lack of grid delivered electricity in many areas furthercomplicates delivery of basic water and power services. This project is using solar power and heat coupled witha membrane distillation technology to supply both livestock and potentially potable water to small remotepopulation clusters on the Southwestern Navajo Nation.

OBJECTIVEThe Bureau of Reclamation in collaboration with the University of Arizona (UofA), Grand Canyon Trust, and theNavajo Nation have been researching and deploying an autonomous (off‐grid) system to pump and treatbrackish groundwater using solar energy and advanced water treatment. A proof of concept produced at theUofA and is now deployed to the Navajo Nation Leupp research site as an applied research project.

PROJECT PARTNERS

PROGRESS

BACKGROUND INFORMATION

SOLAR DESALINATION USING DISTILLATION on the NAVAJO NATION

Navajo well 5T‐529 near Leupp, Arizona was determined to be the candidate well. The site and well were characterizedand a design was developed for a test facility. The test facility was constructed and the solar powered pumpingsystem was installed into the well 375 feet below ground surface. The Concentrating Photovoltaic Thermal HybridSystem (CPVTHS) was installed, tested, and is now operational at the site. The Membrane Distillation (MD) system hasbeen installed and data collection and optimization is now underway (Winter 2015).

Figure 4. Membrane Distillation system racks. (Courtesy of Dan Serwon)

Figure 5.  Concentrating Photovoltaic Thermal Hybrid System (CPVTHS). (Courtesy of Mitch Haws)

Figure 6.  Solar Desalination test facility. (Courtesy of Mitch Haws)

Figure 7. Well Site 5T‐529 system operation schematic. (Courtesy of Mitch Haws)

Ardeth Barnhart, Renewable Energy Network (UAREN); Wendell Ela, Department of Chemical and Environmental Engineering ‐ University of Arizona 

Mitchell Haws, Kevin Black, Henry Corretjer;  Phoenix Area Office ‐ Bureau of Reclamation

Figure 1. The Navajo Nation covers 27,000 square milesincluding parts of Arizona, Utah, and New Mexico.(www.navajobusiness.com)

Figure 2. View of the well site located near Leupp,Arizona. (Courtesy of Mitch Haws)

Figure 3. Sampling waters from well 5T‐529 near Leupp,Arizona. (Courtesy of Mitch Haws)

Table 1. Groundwater Quality Survey. Much of thegroundwater in the Navajo Nation is brackish with TDSvalues above the Secondary drinking water standard of 500mg/L.. Other contaminate above the standards are found insome well which includes nitrate, arsenic, uranium and iron.

517Bidahochi

583 LowerGreasewood

522Dilkon

529Leupp

pH 8.52 7.65 8.15 7.5ORP, mv 140.67 62 131 137.33TDS (calc),

mg/L 1298 356 261 1330TOC, mg/L as C 1.55 1.63 0.57 0.43

Alkalinity as CaCO3 253 268 200 208Cl‐, mg/L 263.2 54.4 18 474.5SO4

2‐, mg/L 428.3 15.9 27.3 242.3

NO3‐, mg/L 26.873 0.118 15.025 0.981

 avg Na+, mg/L 410.71 67.42 50.93 254.10avg Ca2+, mg/L 10.92 46.08 16.20 78.37avg Mg2+, mg/L 9.47 20.06 20.30 52.30avg Fe, mg/L 0.31 0.45 0.02 0.87U, mg/L 0.029 0.003 0.008 0.003

avg Si, mg/L 7.32 15.27 10.47 4.37As, mg/L 0.0141 0.0053 0.0014 0.0059

http://originals.azpm.org/seekingwater/

originals

Partners

• Navajo Nation• University of Arizona• Grand Canyon Trust• Phoenix Area Office - Native

American Affairs Office• Provo Area Office• Reclamation’s Office of Research

Questions?

Mitch HawsWater Agreements Planner

Program Development DivisionPhoenix Area Office

623‐773‐6274mhaws@usbr.gov