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> Do we really need expensive desalination in California?

It’s a good question, and it’s been discussed quite often in recent media sources for the past two weeks due to the rejection of the proposed Poseidon plant in Huntington Beach.

The honest truth is you could probably argue for both sides. Realistically, it’s cheaper and less environmentally harmful to promote non-desal measures, but not as easy to see quicker and observable benefits. The problem with the latest proposal was that it had a lot of problems, and the company behind it has a paper trail of small scale disasters in its wake (see the failure of the Tampa Bay facility, for example).

I personally believe that this is the kind of project that could benefit from a closer partnership between the government and private industry. From what I can tell, the technology is mature and feasible, but every time someone tries to design and implement it in the states, they seem to drop the ball.

I would be curious to see the record of success of other large scale projects outside the US. I’ve heard about the benefits and risks of the plants in the Middle East and elsewhere, but I don’t know the details.




Id imagine a lot of the other desal plants (esp. those in Saudi Arabia) are less than obligated to admit to their resource usage and waste products. Apparently desal is very energy intensive. OP pointed out using solar but I would like an equivalent of how many 400W solar panels does it take to make 1 gallon desal water.


No idea, but AMTA reports 2.5 to 3.5 kwh/ m3 (10-13 kwh/kgal). They write: "Based on nationwide data from the Energy Information Administration, a typical refrigerator average annual energy usage is 1,400-1,500 kwh. Using the average US water use per household of 100,000 gallons per year, the energy requirement for supplying desalinated water to a house in the US will be less than an old refrigerator, but the same as a newer, more efficient refrigerator power use."


My small desalination rig uses about 1200 watts and makes 30 gallons per hour. It cost me $3500. So it’s doable with 3 panels for this 2 person household.

I’d imagine a plant would benefit from economies of scale. Though these benefits could get eaten up by cost overruns. Frankly, it seems the hurdle in California is working through the people issues/concerns than technical problems.

It’ll be interesting to see the stats on this new desal technique when they have a product for sale.


1200 W for 30 gal/h works out to 10.6 Wh/L (or 38 kJ/L).




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