As the people in California probably know, water is getting more and more tricky to obtain. Everything that’s alive needs water to survive. After the earthquake in Haiti, water was scarce, and people were starting to die of thirst. For Haiti, after an earthquake and with its limited resources, one might expect to see water shortages. Compare that to California, however, which has an economy bigger than some countries, and you see how critical the situation really is.
There is, however, one resource that could solve the water issues after a natural disaster, and in places with perpetual droughts, like California: the ocean.
Sure, the ocean may be filled with water, but that doesn’t mean it’s easy to convert into drinking water. Ocean water is filled with salt, which is difficult to remove. This process is known as “desalination.” Since this process is difficult, it is often considered more cost effective to simply pipe in water from elsewhere. Fortunately, some of the world’s brightest minds are on the case.
USAID recently announced the winners of the Desal Prize, which is part of a competition to create affordable desalination opportunities for developing countries. To win the price, the solution must be cost effective, environmentally sustainable, and energy efficient.
MIT took home the gold, along with its partner, Jain Irrigation Systems. The system they developed relies on photovoltaic cells (PV), which charge up a large bank of batteries. The batteries then power a system which uses electrolysis to separate the water from the salt. This works because dissolved salt particles have a slight electric charge, so they are drawn out by a small electric current being run through the water. The team didn’t stop there, as they also are disinfecting the water with ultraviolet lights as it passes through the system.
In Chile and California, solar powered desalination plants are already being considered. However, the cost of building out a large scale desalination plant powered by the sun is high. Nevertheless, proponents hope that in the future, the technology could provide water to large numbers of people.
Durability of the system is key, as a structure that requires constant upkeep would not last long in a rural area. The MIT/Jain group tested their system at the Brackish Groundwater National Desalination Research Facility in New Mexico, where the system ran for 24 hours at a time, cleaning 2,100 gallons of water each day. They will continue to test the technology in harsher environments, including letting everyday farmers use the system to provide water for farm irrigation.