Graphene-based sieve turns seawater into drinking water (2017)
One of the key questions for desalination is how good can it get. It turns out that many desalination plants are probably close to the thermodynamic limit [1, 2], which means that even with new technologies it's likely energy costs aren't going to go down by an enormous amount. The Ars review suggests the best we can do is a factor of 3-4x, which is nice, but if we're expecting this to solve all our water needs we may have another thing coming. For reference, the cost of water is as low as $25 per acre-foot [3] in CA, and the most recent desalination plant in San Diego is on the order of $2000 per acre-foot [4]. Even some of the other estimates in [3] suggest that the average cost of water is something like $7-800 per acre-foot, which would put us right around where the thermodynamic limit suggests the floor of desalinated water would be.<p>Obviously this is great new tech and more water purification technologies are always needed, but given the physical boundaries it's unlikely we'll be able to use desalination as the only solution to water crises. We should still be figuring out ways to be more efficient about water use.<p>[1] <a href="https://arstechnica.com/science/2011/08/desalinization-is-this-as-good-as-it-gets/" rel="nofollow">https://arstechnica.com/science/2011/08/desalinization-is-th...</a><p>[2] <a href="http://science.sciencemag.org/content/333/6043/712" rel="nofollow">http://science.sciencemag.org/content/333/6043/712</a><p>[3] <a href="http://www.cpuc.ca.gov/uploadedFiles/CPUC_Public_Website/Content/About_Us/Organization/Divisions/Policy_and_Planning/PPD_Work/PPD_Work_Products_(2014_forward)/PPD%20-%20Production%20costs%20for%20new%20water.pdf" rel="nofollow">http://www.cpuc.ca.gov/uploadedFiles/CPUC_Public_Website/Con...</a><p>[4] <a href="https://www.mercurynews.com/2014/05/29/nations-largest-ocean-desalination-plant-goes-up-near-san-diego-future-of-the-california-coast/" rel="nofollow">https://www.mercurynews.com/2014/05/29/nations-largest-ocean...</a>