Water Resources Engineering (WRE) connects engineering hydrology and hydraulics with global, economic, environmental, and societal issues. Our student Emma Aversa makes this connection here…

With the exponentially increasing population, our world’s fresh water supply is fading faster than we foresaw. On July 23rd, 2015, ThinkProgress.org published a news article by Ari Phillips entitled “Have You Heard Of Solar Desalination? If Not, You Will Soon”, in which WaterFX, a California water producer, claims they may have a solution to our water crisis.

Solar energy and desalination have been two hot topics in the past decade, but they are often discussed as separate entities. WaterFX hopes to bridge their gap with the creation of solar powered desalination technology. In the article, they discuss a solar powered desalination plant in California that will generate 1.6 billion gallons of clean water annually with no negative by-products. The article focuses on a technology called “Aqua4 technology,” which produces fresh water by evaporating the H2O with heat that is generated from parabolic solar panels. The condensation is then precipitated back out at greater than 90% efficiency, and salt is left as a useable by-product (Phillips, 2015).

WaterFX’s technology seems like a viable option. According to an article from National Geographic, California isn’t the only place trying out solar desalination. Texas, Australia, and the Middle East are all working to get solar desalination plants up and running. Masdar City plans to have a system selected and implemented by mid-2016 (Lavelle, 2015). In addition to solar energy, wind energy is also being considered in Texas, though they worry, with intermittent wind power, if maintaining a consistent pressure for the desalination will be possible. To further support their argument, a more in depth explanation of the process would’ve been beneficial. WaterFX states that no exact costs have been calculated. However, they believe their process will run at ¼ cost of traditional desalination. An article published on SFGate.com says, in general, solar desalination costs approximately $450 per acre-foot vs $2000 per acre-foot for traditional desalination (). This would support WaterFX’s claim, but this pertinent information was nowhere to be found in ThinkProgress.org’s article. Currently, cost is one of the limiting factors on desalination, with its lack of fiscal details, this article leaves important questions unanswered.

The biggest issue with traditional desalination is its environmental impacts. Desalination plants use a reverse osmosis process, which is highly energy intensive, to get clean water and salty brine out of seawater. The salty brine is then dumped back into the oceans, killing off fish and other sea life (Phillips, 2015). In addition, the energy required is so immense that many are worried about the fossil fuel emissions. This past December, California opened the world’s largest desalination plant in Carlsbad, CA. Prior to its opening, the plant was facing charges from the San Diego Coastkeeper, who claimed the plant’s long-term supply plan was violating the California Environmental Quality Act (Littlefield, 2015). Solar desalination provides solutions to both the energy and by-product issues associated with traditional desalination. In the International Journal of Modern Engineering Research (IJMER), the disconcerting fact that all conventional methods of desalination are inefficient is addressed. The author says that traditional desalination processes can “cause environmental hazards because they are fossil-fuel driven and also because of the problem of brine disposal”. They also argue that that all methods of solar desalination are more energy efficient, regardless of design (Karhe, Y. B., & Walke, P. V., Dr.,2013).

In conclusion, solar desalination technology is a feasible long-term solution to our water security issue. Although many of the details are vague, it is clear that traditional desalination is impractical if we intend to leave a more sustainable footprint. Given time and sufficient research, solar desalination could revolutionize the way we get drinking water and deal with the water crisis.

Image:

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Figure 1 Parabolic solar pannels at WaterFX’s demonstration solar desalination plant in California

URL: http://thinkprogress.org/climate/2015/07/23/3682598/first-commercial-solar-desalination-plant-in-california/

 

Works Cited:

Fagan K. California drought: Solar desalination plant shows promise. SFGate. 2016. Available at: http://www.sfgate.com/science/article/California-drought-Solar-desalination-plant-5326024.php. Accessed February 7, 2016.

Karhe Y, Walke D. A Solar Desalination System Using Humidification- Dehumidification Process- A Review of Recent Research. International Journal of Modern Engineering Research. 2013. Available at: http://www.ijmer.com/papers/Vol3_Issue2/CH32962969.pdf. Accessed February 7, 2016.

Lavelle M. Can Sun and Wind Make More Salt Water Drinkable?. Newsnationalgeographiccom. 2015. Available at: http://news.nationalgeographic.com/news/energy/2015/02/150202-energy-news-renewable-salt-water-drought/. Accessed February 7, 2016.

Littlefield D. Concerns rise over environmental impact of Carlsbad desalination plant. latimescom. 2015. Available at: http://www.latimes.com/local/california/la-me-san-diego-water-20150731-story.html. Accessed February 7, 2016.

Phillips A. Have You Heard Of Solar Desalination? If Not, You Will Soon. ThinkProgress. 2015. Available at: http://thinkprogress.org/climate/2015/07/23/3682598/first-commercial-solar-desalination-plant-in-california/. Accessed February 7, 2016.

 

 

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