In parched California, desalination of seawater is becoming an increasingly attractive option for potable water. In Saudi Arabia, more than two dozen desal plants already provide some 70 percent of the water used in cities. Australia, too, has in recent years embraced salt removal as a path to assuring the availability of drinking water.
You might have noticed that these are all places of great wealth by global standards, highlighting that desalination is expensive – so expensive that even in Europe, desalination expansion plans are struggling to unfold as planned. And desalination is expensive because the process is energy intensive, accounting for up to 70 percent of costs.
But the industrial giant GE, working with Aramco Entrepreneurship, a subsidiary of Saudi Aramco, is looking to change the desalination cost equation.
Desalination, GE announced this week, is the focus of a new ecomagination open global technology challenge, with $200,000 – including a first prize of $50,000 – up for grabs for the best ideas on how to “accelerate the development of solutions focused on improving the energy efficiency of seawater desalination.”
“Ecomagination” is a bit of a catchall that GE uses for its efforts to tackle challenges in energy, efficiency and water. It can be seen in R&D and in products, and has genereated $160 billion in revenue since launching in 2005, according to the company. And it can be seen in GE’s internal resource use: The company says it has cut greenhouse gas emissions 34 per cent since 2004 and use of freshwater by 47 per cent since 2006, adding up to $300 million in savings.
For desalination, the company says that the solutions it seeks to back could come in areas that include “development of new advanced materials, innovative uses of renewable energy, and/or integrating desalination with processes like mineral recovery.”
In the Middle East, home to much of the world’s desalination, the Saudis have mainly relied on fossil fuels to power thermal desalination plants, using the equivalent of 300,000 barrels of oil day to boil the water (that’s as much oil as Sweden uses on a daily basis for all purposes). But the kingdom is hoping to transition to using solar photovoltaics to drive desalination through reverse osmosis. Improved membranes could make those systems work more efficiently.
In California’s San Joaquin Valley, meanwhile, a company called WaterFX has demonstrated its ability to purify saline discharge drainage by using a “Concentrated Solar Still” paired with advanced absorption technology. For its business, WaterFX is focused on treating agricultural runoff, but the company has a goal of extending its techniques through what it calls an “open source water movement.”
Another possibility for less energy-intensive desalination could come from water itself, in the form of wave power. In Perth, Australia, Carnegie Wave Energy, with government help, is developing a wave-driven desalination project. The Boston-based company Resolute Marine Energy is trying to make a business of clean water, as well, targeting areas like West Africa where it’s not just the cost of energy that’s a stumbling block to desalination, but access to any energy at all.
