Solar-Powered Water Desalination System to Address Water, Energy Crises

Yi Zheng

MIE Associate Professor Yi Zheng recently received a $355,408 Soleeva Energy Innovation Award to develop a functional interfacial structure for solar driven water desalination and purification. The system would also be integrated with solar photovoltaic systems.

San Jose, California-based Soleeva Energy is sponsoring the research. Zheng said he will be working with Soleeva President and CTO Ralph Ahlgren, as well as the company’s R&D team, on the “Functional Composites for Solar Energy Exploration” project.

“My research focused on solar energy harvesting,” Zheng explained. “I developed a novel structure to purify and desalinate ocean water. My recent work on a low-cost solar-driven water desalination system has demonstrated the highest-to-date evaporation rate of fresh water.”

The system achieved an evaporation rate of 2.48 liters of freshwater per unit area per hour from salt water, which is nearly six times more than the natural evaporation rate of water.

“This pioneer work will shed light on an innovative solution to address the global water and energy crisis,” Zheng said.

Soleeva’s Ahlgren added that the plan is to use his company’s technology to create a localized source of high temperature water that will work with the evaporator technology that Zheng has developed.

“We will hopefully solve the world’s freshwater problem in the next year or so,” Ahlgren said.

Affordable, universal applications for solar energy

Zheng’s research aims to enhance solar energy conversion and harvesting, using novel, high-efficient, low cost materials. The system utilizes spectral selectivity to sunlight, as well as self-adaptivity. This includes “high-temperature resistance, self-cleanness, super-hydrophobicity and solar absorptive tunability under different seasonal environments,” according to the project summary.

The research will center around three main tasks: tunable spectral selectivity of solar absorbers/emitters for thermophotovoltaics, retention of thermal/optical properties with excellent high-temperature resistance, and solar-driven water treatment using a low-cost interfacial structure.

This will transform the novel low-cost functional composites with advanced thermal properties for harvesting renewable energy and for developing green energy techniques, Zheng explained.

Additionally, this type of water desalination and purification has both residential and commercial applications.

Third-world countries that do not have easy access to freshwater can greatly benefit from this technique, Zheng said.

“They don’t have to spend money purchasing freshwater,” he said. “Instead, they can have a small container in a yard, for example. It is placed in the sun, and then my structure is placed on the contaminated water. It will help to desalinate and purify the water, transforming it into drinking water.”

Ahlgren stressed that there are three things people need to get out of the poverty cycle: water, food, and electrical power. Soleeva and Northeastern are trying to hit all of them.

“With this you can extract freshwater from ocean water, and also use it to remediate polluted areas where groundwater contamination is significant,” Ahlgren said. “For example, in Bangladesh, 60% of the freshwater is contaminated with arsenic. You have the choice between spending earnings on buying bottled water or drinking the water available to you. You either can’t afford it, or you drink it and it will kill you slowly over time.”

Zheng’s technology absolutely has the potential to have a global impact, he added.

“We’re fortunate to have the opportunity to work with him on this,” Ahlgren said.

As an engineering professor, Zheng said that he wanted to utilize his skills and work toward large, positive change on the world.

“I wanted to do something meaningful with my life,” he said. “The benefits for this project are far-reaching. It will be quite useful and have a great impact on people.”

Related Faculty: Yi Zheng

Related Departments:Mechanical & Industrial Engineering