Solar Water Desalination To Combat Droughts?

Using the sun to desalinate water isn’t anything new. In fact, for thousands of years, people have used simple evaporative methods to harvest solar energy in an effort to make polluted, stagnant water usable for drinking and to irrigate land.

GoSun believes in the power of the Sun to desalinate water. That's why we created a water purifier called the Flow, a solar-powered water purifier that is small enough to fit in a backpack but purifies enough clean water to wash your dishes or even take a show.

It's the world's first portable solar-powered purifier that works well enough to enable you to live comfortably off the grid. Instead of manual pumping, a USB-powered pump enables the delivery of water wherever you need. For good measure, it includes a power bank that supplies power to the pump but can also run off a mobile phone or be charged directly by a solar charger (like this). 

And it purifies water well. Really well. Like, 9999 parts per 10,000 of water-born pathogens well. 

Why Solar Desalination Can Work

Let's shift to looking at industrial approaches to desalination. While small solar distillery plants have existed for some time; today many countries, including Chile, Saudi Arabia, and the United States have created large-scale solar desalination projects designed to solve serious issues including draught and even the shortage of safe, clean drinking water. The plants are lauded by environmentalists for their use of renewable energy as a way to reduce both costs and emissions.

A few years ago, Saudi Arabia announced plans to build the world’s first utility scale solar desalination plant that will turn 60,000 square meters of sea water daily into fresh water. And in Fresno, CA, WaterFX, a solar thermal desalination plant – the only of its kind in the U.S., has developed a way to turn contaminated irrigation run-off into clean water for Panoche Water and Drainage District. The company produces about 14,000 gallons of fresh water each day, but plans to generate 2 million gallons daily by the end of the year.


Solar Desalination Benefits

  • Environmentally friendly – less emissions produced in operations
  • The plants are typically lightweight and easy to move and transport
  • Easy to set up on- or off-shore
  • Low maintenance costs and inexpensive to operate thanks to free solar energy
  • Wildlife friendly - ocean water can be preserved, thus benefitting the ecosystem

Of course, while solar desalination could be an exciting conservation effort that brings great benefits in the future, it’s not without its cons. Scientists are still cautiously optimistic about large scale solar distilling – mostly because the plants require a large amount of heat to produce results.


Impact of WaterFX: Economic, Environmental & More

According to Aaron Mandell, a co-founder of WaterFX, water from the solar desalination plant costs much less for farmers than conventionally desalinated water: $450 an acre foot compared to $2,000 an acre-foot. The method of desalinating the water is simple: As water starts running off the hills near the plant, it collects minerals including selenium and boron that are unfit for human consumption. After the plant collects the water through a drain system under crops, it sends it through pipes and tanks, and the water gets heated via the plant’s solar reflector – a long tube that creates steam that then in turn condenses the water into clean water.

It’s hard to underestimate the impact solar desalination plants like WaterFX can have, not only on California, but across the globe. Solar desalination plants are much less expensive than plants which use reverse osmosis that cost about $1 billion to operate. And in California, where agriculture accounts for 80 percent of the state’s water use, data suggests that about a million acre-feet of irrigation drainage could be reused thanks to solar desalination.

Besides being a benefit to the economy, Mandell sees solar desalination as a remedy for a world crisis: global warming. “Droughts come and go, but the water problem in California is driven by climate change,” he told “While lack of rain is temporary, elevated temperatures due to a warming climate is permanent and as a result will have a long-lasting impact on the amount of available water.”

Considering statistics by the World Resources Institute, that at least 3.5 billion people will experience water shortages in the future , solar desalination plants could have a major positive impact on the world’s future.


Photo credit: usembassyta / CC BY-SA 2.0

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