Researchers at Stanford have pioneered a low-cost technology that can capture the powerful blue energy generated when freshwater mixes with ocean water.

In the study, wastewater treatment plants were identified as potential beneficiaries. The process is ‘energy-intensive, accounting for about three percent of the total U.S. electrical load’ – so making these sites energy independent with clean power would help advance the sustainability agenda.

“Blue energy is an immense and untapped source of renewable energy,” explains study coauthor Kristian Dubrawski, a postdoctoral scholar in civil and environmental engineering at Stanford. “Our battery is a major step toward practically capturing that energy.”

A prototype was successfully tested at wastewater plant in Palo Alto but the tech could be employed anywhere fresh and saltwater come together.

“It is a scientifically elegant solution to a complex problem,” added Dubrawski. “It needs to be tested at scale, and it doesn’t address the challenge of tapping blue energy at the global scale – rivers running into the ocean – but it is a good starting point that could spur these advances.”

The study was published in American Chemical Society’s ACS Omega.