Innovative desalination technologies to solve one of the world’s biggest problems

By Shashi Buluswar 04 June 2015

A team operates a complex system of water tanks and hydraulics. Meeting the global demand for water will require innovative and low-cost desalination methods using renewable energy. Photo by: DAI

Water will be the defining problem of the next 50 years. After spending the past two years delving into critical technological advances that my team of scientists, researchers and I believe are vital to moving the needle on poverty, we agree that it’s probably the single most important issue that needs to be solved.

We set out to find the big things that matter, trying to identify the scientific and technological advances that could have a transformative impact on global development. Two years of investigation and analysis, combined with input from more than 500 experts around the world, culminated in our “50 Breakthroughs” report — a study to give philanthropies, aid agencies, businesses and technologists a blueprint for where to invest their resources to achieve the highest impact.

Sponsored by the Lawrence Berkeley National Lab, Higher Education Solutions Network at the U.S. Agency for International Development’s Global Development Lab and Lemelson Foundation, among others, “50 Breakthroughs” is intended to generate a conversation around the role of breakthrough technologies in transforming international development.

Technology possesses immense potential to aid in solving the world’s most pressing problems; however, we often fall short of reaching the scale or impact needed. Focusing on “breakthroughs” — areas where game-changing technologies are most required — can help decision-makers invest smarter and better to enact change.

Through our research, we discovered that one of today’s most needed breakthroughs is a cost-effective, energy-efficient method for desalinating water using renewable energy. A breakthrough desalination technology could mitigate future problems of groundwater salinization  — for instance, due to overextraction or sea level rise — as well as expand freshwater resources to cater to growing water demands. While large-scale desalination plants and systems exists, there are no sustainable options for smallholder farmers in developing countries to tap into desalination’s potential.

However, substantial research and development work is required for this breakthrough to become a reality. That’s why emerging solutions like those in the recent Desal Prize competition, the second round of Securing Water for Food: A Grand Challenge for Development, are so important.

Through the Desal Prize, five finalist teams traveled to Alamogordo, New Mexico, to test their technologies’ capacities to produce both potable water and water suitable for agriculture from brackish groundwater. Two winning teams and an honorable-mention team were selected to pilot their technologies in developing countries where water availability for agriculture is a significant issue.

Conventional desalination technologies require a large amount of energy to operate, making them costly and impractical for smallholder farmers who live in rural areas with limited, if any, access to electricity. To address this, part of the competition required teams to develop technologies that operate solely on renewable energy, forcing them to come up with innovative solutions.

For instance, the first place team comprising the Massachusetts Institute of Technology and Jain Irrigation Systems, designed a photovoltaic-powered electrodialysis reversal system that desalinates water by using electricity to pull charged particles out of the water and further disinfect the potable water using ultraviolet rays. MIT and Jain Irrigation Systems specifically designed their system for low energy consumption, adapting traditional electrodialysis to limit costs, especially in off-grid areas.

In order to be effective and sustainable, desalination systems must also minimize environmental impact. Disposal of the concentrate these systems discharge is one of the major obstacles preventing the deployment of scalable, low-cost desalination; the concentrate wastewater produced by desalination is often disposed of in rudimentary evaporation ponds, which require a large area of land and are prone to leaks, leading to salinization of the soil.

In the Desal Prize, competitors were required to achieve a high-system water percent recovery  — or the ratio of produced freshwater water to brackish groundwater used — and minimize concentrate. By using its innovative zero-discharge desalination technology, second-place team University of Texas at El Paso’s Center for Inland Desalination Systems aims to reduce water waste in the desalination of groundwater by conventional electrodialysis processes. During the testing, it was even able to remove gypsum — a mineral commonly found in groundwater in the region — to be repurposed as a component of fertilizer or wall board!

The honorable-mention team, Green Desal, offered a new take on the most common desalination process: reverse osmosis. The Green Desal team has a truly global representation with members from the Asian Institute of Technology and Management, National Center for Agricultural Research and Extension, State University of Ponta Grossa, Technion-Israel University of Technology and University of North Texas. Similarly, its innovative approach integrates a number of proven technologies — reverse osmosis, ion exchange, nanofiltration, remineralization and disinfection — combining the best elements of each into a single technology that utilizes a hybrid renewable energy power source comprised of both solar and wind power.

This competition revealed a number of emerging solutions with tremendous potential to provide water for agriculture and drinking for smallholder farmers in developing countries. We need to continue to provide opportunities for innovation that spark ideas from those not traditionally engaged in development.

Moreover, we need to engage experts across diverse sectors and fields who can bring their knowledge and skills to bear on significant issues. By focusing on problems for which new technologies are critical, we can invest in innovation and a new paradigm of technologies for a new set of users.

You can help shape our coverage on global development innovations by emailing or tweeting #innov8aid.

About the author

Shashi Buluswar

Shashi Buluswar is the co-founder and executive director of Lawrence Berkeley National Laboratory’s Institute for Globally Transformative Technologies. Before founding LIGTT, Shashi was a partner at Dalberg Global Development Advisors, an organization which gives strategic advice to governments, the United Nations, NGOs and foundations on issues such as economic development, health, agriculture, climate change, education and post-conflict reconstruction.

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