U.S.-based NREL expands research into geothermal & solar desalination

Water (source: pixabay)
Alexander Richter 11 Dec 2018

The National Renewable Energy Laboratory (NREL) is actively expanding research in desalination capabilities by partnering with technology leaders on several groundbreaking projects with geothermal and solar energy.

U.S. National Renewable Energy Laboratory (NREL) scientists have a long history of successfully analyzing geothermal and solar energy data. But they are now actively expanding research in desalination capabilities by partnering with technology leaders on several groundbreaking projects, as announced by NREL. The purpose is to explore geothermal and solar-thermal technologies for creating fresh water from otherwise unusable water.

The ability to desalinate otherwise non-potable water is a vitally important process, but its cost can be high. Fortunately, there is potential to tap otherwise unused renewable heat to drastically reduce the cost of thermal desalination. Applied in the right locations, thermal desalination could mean economic viability for water treatment.

“Water scarcity is a growing problem throughout the world. The ability to apply renewable energy solutions is key to a sustainable water future,” said Craig Turchi, principal engineer within the Thermal Sciences Group at NREL.

Using Heat from the Earth

The “Desalination of Impaired Water Using Geothermal Energy” project is paramount in the geothermal approach to desalination. And taking the lead in this project is Turchi, assisted by researchers at the Colorado School of Mines, University of California Los Angeles (UCLA), and Ormat Technologies. The goal is to apply underused, low-temperature geothermal resources to the desalination process.

Thermal desalination technologies use more energy and are generally costlier than reverse-osmosis desalination. However, the thermal desalination methods, such as membrane distillation (MD), use mostly thermal, not electrical energy. So, to overcome this energy and cost challenge, the project is using untapped or residual heat in geothermal resources for the MD heat source. Along with this approach, the project is also researching coatings designed to protect and improve membrane distillation.

Although NREL has effectively wrapped up its role in the project, work continues at UCLA with David Jassby and his team. More research must still be successfully accomplished by the scientific community before geothermal desalination is cost-effective. However, advances have been made in producing high-quality water from geothermal brines at lower cost than traditional thermal distillation, and membrane coatings have been shown to provide the ability to minimize and remove undesired scale formation.

And Heat from the Sun

NREL is also working with industry partners using solar desalination in solar-thermal technologies. Specifically, three projects—each with a different partner—are making major leaps toward reducing the levelized cost of water production by first lowering the levelized cost of heat.

For further details see link below.

Source: NREL