Experts warn of looming threats to water and energy security

Presentation on ‘water-energy nexus’ free at Clemson University

CLEMSON, SC – Looming threats to water and energy security will come into focus Thursday when one of the nation’s leading experts on the “water-energy nexus” visits Clemson University.

The gathering comes as the Department of Energy seeks $38 million to fund major elements of a plan that proposes a strategic approach to the water-energy nexus and says collaboration with partners will be crucial.

The nexus is an emerging branch of research with a simple idea at its heart. Providing clean water takes a lot of energy, and generating energy takes a lot of water. So exploring the connections can lead to innovative, efficient solutions for both.

Clemson’s seminar is called the “Energy-Water Nexus: National Perspectives and DOE Initiatives.”  The speaker will be Mike Hightower, a leading civil and environmental engineer at Sandia National Laboratories in New Mexico.

About 40 Clemson faculty members recently formed the Water-Energy Consortium to engineer new ways of providing clean water and energy to a fast-growing world with a changing climate, said Dr. Gary Amy, the consortium’s organizer and a Dean’s Distinguished Professor in the College of Engineering and Science.

“Water is becoming limited in some regions because of changing precipitation patterns,” Amy said. “Meanwhile, water consumption by the energy sector is expected to expand significantly in the next two decades.

“We need sustainable solutions now. Clemson is well-positioned to play a leadership role in finding them.”

Hightower will address the issues that arise from the lack of a federal agency that would ensure the nation has adequate water supplies for energy generation and production, organizers said.

His presentation will be free and open to the public. It goes from 10-11 a.m. in room 118 of the Academic Success Center. A question-and-answer session will follow.

The seminar comes as members of the consortium aggressively seek new partners across academia, government and industry.

One project that has already begun and could be expanded is focused on generating a new form of renewable energy where rivers flow into the sea. When two streams of different salinity mix, it creates energy.

“All the energy that is being lost— which is an incredible amount of energy — can be gained back by putting a membrane in between,” said Scott Husson, a professor of chemical and biomolecular engineering.

Husson has begun work with David Ladner, an assistant professor of environmental engineering and Earth sciences. They are developing new membranes for pressure-retarded osmosis (PRO), an emerging type of power generation.

The membrane would allow water to pass through, but not salt. As a result of osmosis, fresh water would naturally go through the membrane to balance the saltier side, creating pressure that could drive a turbine to generate electricity.

One of the primary challenges, though, is creating a membrane that is both thin and strong. That is where Husson and Ladner are focusing their efforts.

Some work in this area has been done around the world, with limited success. Statkraft, a state-owned electric company in Norway, opened a PRO plant in 2009. The power output wasn’t economical, but the plant demonstrated the technology’s possibilities.

“It showed that there’s a lot of potential here and that if membranes could be developed that could be able to meet those standards, it could be one way to recover an incredible amount of energy,” Husson said.

Researchers are hoping that PRO could help remove one of the barriers to building more desalination plants.

Taking salt out of seawater requires an enormous amount of energy and has been cost-prohibitive for many communities. But if PRO works, it could help generate the energy needed to pump saltwater through membranes to create drinking water.

Ladner said energy could also be created with the salty brine that is produced by membranes at desalination plants. The brine now is discharged back into the ocean, but it could be an excellent salty-water source to send to PRO, creating energy.

“Treating water for zero- or low-energy would be ideal,” he said. “We’re looking for sustainable systems, things we can do not just for the next decade but for the next several decades and the next several centuries.”

Tanju Karanfil, the associate dean of research and graduate studies in the College of Engineering and Science, said Clemson is ideally positioned to take a leadership role in research that will help the world better manage its resources.

“Climate change, energy security and environmental responsibility are all at stake,” he said. “We’ve assembled the knowledge and expertise needed to address these important global challenges. With the right partnerships, we can find more sustainable ways to supply water and energy to a growing world.”