Salty or Sweet? Harnessing the Sun for Desalination

Here is one for all of the science buffs! Two Canadian engineers recently unveiled a cheaper desalination method that harnesses the sun to power the desalination process, which in turn could lower the cost of desalination by almost 80%. This process requires a bit more ingenuity than the typical prototype, but if it does work as described then this might prove to be one of many answers used to solve the linger issue of water scarcity.

I will try to sum up their process as best I can (with the limited science and engineering knowledge that I have).  The engineers, Ben Sparrow and Joshua Zoshih, believe that they can create an ample amount of fresh water with less than 1 kWh of electricity. The only energy required is a very small amount (remember, less than 1 kWh) used to pump the water through the system, As described in The Economist, “Their process is fuelled by concentration gradients of salinity between different vessels of brine. These different salinities are brought about by evaporation.” Therefore, no other source of “paid” power is needed to produce this freshwater because the rest of the energy comes from natural sources (sun, air). See visual below for more information!

The article goes into more detail, and it is interesting to compare this system to the ones that are currently proposed by businesses such as G.E. It does appear that there are striking benefits to this system such as the performance of this process improves in arid regions (which are the regions that most need this type of technology), and it requires less pre-treatment and chemicals than traditional processes.

Perhaps there is more to this story than at first meets the eye? Admittedly, I have very little knowledge of desalination, but the proposed process seemed ingenious when I read about it. Perhaps there are many more of these ideas floating out there? I also am sure there are cons to this system. However, I will need to do a little more research to understand that side of the story a little better.


Security and Water in Israel

A recent report from Amnesty International finds that Israel has developed discriminatory practices that have created sever water scarcity for Palestinians in the West Bank and Gaza.West_Bank_&_Gaza_Map_2007_(Settlements) Much has been made of the potential for resource scarcity to cause violent security issues.  In this case it seems that insecurity has resulted in resource scarcity.  According to the Amnesty report Israel has prevented Palestinians from accessing the surface water of the Jordan River, dominated use of the Mountain aquifer located under the West Bank, and prevented capital upkeep of sanitation stations in Gaza that are critical to refreshing the coastal aquifer.   The impacts of the imbalance land heavily on the Palestinian households dependent on water from these natural sources.  Decreased agricultural productivity and high costs to get needed clean water has placed substantial burdens on the economic well-being of affected households.  The ongoing violence in Israel may not be caused by resource scarcity but it seems likely that the inequality and desperation caused by discriminatory Israeli water policies breeds societal insecurity.

Water, water, everywhere, but not a drop to drink..

People return to flood-hit homes

People return to flood-hit homes

Ahmer Ali, 28, returned with six family members to find his house virtually destroyed and his rice crop gone. This plight is not shared by Ahmer and his family alone; thousands of southern Indians were affected by the floods in Andhra Pradesh and Karnataka states by torrential rains after severe drought.

This natural disaster killed at least 269 people and the damages in the two states are estimated to be $4.6 billion. The torrential rains were the worst in decades and displaced more than 2 million people. The water has now slowly started to recede and people are slowly moving back to their ‘home’. Continue reading