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Comment by JamesLeonis | Hacker News Reader

I'm working on this problem right now. I believe the path to cheap water is through a massive fleet of solar stills floating in the South Pacific that passively collect evaporated water. Currently I'm working through my assumptions about biodegrading materials + construction, average loss (actuary) of such vessels in the region, logistics of collection/distribution over wide oceanic conditions, and how to build such a fleet incrementally without a massive amount of starting cash.

The big reason I saw this as an opportunity is the huge investments Saudi Arabia and the surrounding region are investing in their own water supply, and the knowledge that California's water politics will push them in the same direction. While traditional desalinization will help, the costs in material and electricity are prohibitive for small players.

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Isn't transporting all the water likely to cost more than distilling it on site?

To be honest I'm not sure. Transportation is one of the largest unknowns in this idea. On top of that, there's also the unknown of offloading the water at a given destination.

My hope is to work out a solution that takes less energy than traditional desalinization for the same amount of water, even with the transportation energy requirements.

Well. You should do some rough calculations on those requirements too with current shipping technology. Are there any water shipping ships?

Oil shipping ships could work

Actually tankers are not cost-viable today (and probably never will be).

A friend of mine and I (both marine engineering professionals in commercial shipping) did a Cost Benefit Analysis on chartering a handy size tanker, cleaning the tanks and shipping water from Alaska to California during the droubt. I no longer have the email that broke the costs down, but cleaning costs aside, the operational costs alone yielded $0.25/gal. The cost of H20 in Ca is about $0.002/gal (cheaper for farmers).

If you're looking to start an H20 ptoduction venture, you need to account for demand factors that will inform the type of product that is needed. For example, if the demand is geographically fragmented and/or geopolitical isolated (e.g. to remote villages in relatively undeveloped or oppressive nations) then a small and very cheap personal H20 generation technology is probably more cost feasible than creating a supply infrastructure.

Just calculate the cost/galon at the end user then compare to today's cost and you'll have your answer.

I think tankers will still work, but the problem has to be attacked from a different angle.

California's water is a repayment on the bond measure for building it's infrastructure back in the 60s. It's somewhere around 80% of the price of water. This is the largest reason for it's seemingly fixed cost and relative cheapness, even during the drought years. Under these circumstances a single tanker is simply a drop in the proverbial bucket.

What California's drought hurts is the entire state's total water carrying capacity year over year. Once that reaches a critical low, California will be spurred to take another water bond project of equal size. I predict this will fund desalinization plants along the coast.

Looking at the problem from this perspective, I'm estimating how much water is produced daily by a given plant. The question then becomes "Can I produce as much water as this plant for less money (loan/maintenance/electricity)?" I imagine this requires a dozen such tankers each day in Los Angeles harbor, each selling at half the cost per gallon.

Now this might be impossible to engineer cost wise because of the very math you mentioned. It also requires a staggering amount of water production, which itself might be impossible. The logistics of managing such an enterprise might crush the venture under it's weight. I'm still working through these assumptions.

Still, you've helped greatly because now I know the current cost to maintain a tanker. It's expensive, but that's a number I can attack to drive down.

> The cost of H20 in Ca is about $0.002/gal (cheaper for farmers).

*$0.25/gal cost should have read ~$0.15/gal.

I was going to say that figure seemed a little high

Double check the need to clean. Dilution is the solution to pollution.

Your average tractor trailer tanker may pick up diesel then switch to orange juice. As long as they put in 95% juice, that's legal.

Do you have a source that orange juice can contain 5% diesel fuel?

I was imprecise. As long as the tanker was filled greater than 95% of capacity with OJ concentrate, that's ok. Shippers aren't in the habit of leaving oil in the tank -- regulations only require rinsing/cleaning for residue in some situations.

It's buried in the CFR somewhere for the Motor Carrier Safety Administration.

I'd really need to see this to believe it. I'd expect more deaths or illness if this was common.

"Ingestion of kerosene is harmful or fatal."

https://en.wikipedia.org/wiki/Kerosene#Toxicity

I use, on average, about 3 litres of gasoline a day and about 250 litres of fresh water. This doesn't include the water used to grow the food I eat and it doesn't include the fuel to bring me my food.

But there is a difference of about two orders of magnitude.

250 litres sounds like a lot - what does the breakdown look like?

I'm using the City of Toronto statistics for our ward and assuming my partner and I are average users.

It's probably higher if you consider that I (well, we) flush toilets in commercial spaces, shower at our gyms etc.

If you're including water for shower/bath, dish and cloth washing, it does not seem a lot.

I forgot the toilets.

I found a breakdown there: https://www3.epa.gov/watersense/pubs/indoor.html

A membrane Pipeline sloping upwards could do it..

Do it in the Antarctic, freeze it, then tow the iceberg.

This sounds totally stupid, but there has been previous work on the economics of towing icebergs to Australia for use as drinking water[1] as well as to Africa[2].

The numbers didn't work out then, but maybe now with higher efficiency solar power (and more advanced wind turbine design) the economics may have changed.

[1] http://www.abc.net.au/science/expert/realexpert/watercrisis/...

[2] http://www.scidev.net/global/water/news/icebergs-africa.html

Nice, reminds me of Asimov's "The Martian Way".

Offshore desalination typically costs ~3x as much as onshore. Obviously, I don't know if that will apply in your case, but thats a good rule of thumb.

Have you spoken with David Zetland? He's a really good guy for running ideas like this by.

I'm expecting a non-trivial YoY turnover on the stills because of degradation and disaster, so those costs likely will still hold. I do read Aguanomics, but I haven't talked with David. Once I have more concrete numbers then I could have a productive talk with him.

Transporting the water is not an unknown. It's really really expensive since water is really really heavy. If transport costs were free or a solved problem we could pipe water from wet places (like BC/Washington/Great Lakes) to dry areas. Transport IS the problem. Some Valley hipster isn't going to solve this with an app or webpage.

Couldn't you just put all the water onto converted oil tankers and bring it right to cities like San Diego or LA?

Freshwater consumption absolutely dwarfs oil consumption. People also ask "if you can build long distance oil pipelines, can't you build long distance water pipelines?" It's not impossible, but it's not particularly affordable either because the value of water per liter is so much lower.

You don't need a pipeline for water most of the time. You can use open canals, which are much cheaper to build.

What about utilizing ocean currents? You deploy the collectors and eventually they end up somewhere close enough to be toed in without using much fuel. Deploy them at regular intervals and go pick them up as they get closer to shore. This is assuming such currents exist and will allow enough time for the collectors to collect enough water.

Long term: yes.

The big problem is I'll not be anywhere close to that level of production for a decade at least. Large scale is quite doable conceptually, but the financial requirements are nearly that of a desalinization plant itself. I need to work my way up to such production.

But to follow that line of thought, I've been investigating FPSOs [1] because of their transportation and "mobile factory" to service the individual stills while out in the "field".

https://en.wikipedia.org/wiki/Floating_production_storage_an...

Best wishes for your project. Why the South pacific ?

Two reasons: low impact to water life and not very active commercial shipping.

Because the evaporation will create a larger percentage of salt, there is a concern that this would affect the local biology. This is double for any industrial accident that happens. However there is a large "Dead Zone" between South America and Australia [1] where both problems will be far away from any life.

The second is there is less commercial and personal ship traffic in that part of the world [2], lessening the possible collisions and other accidents because of wayward stills.

[1] http://www.noaanews.noaa.gov/stories2008/20080305_oceandeser...

[2] https://people.hofstra.edu/geotrans/eng/ch1en/appl1en/mariti...

I believe California has alternative methods to desalinization like the Bay Delta Conservation Plan, or recycling water which reuses 60-82% of water that would otherwise be wasted.

Didn't know about the ocean deserts. Thanks.

Maybe your solar stills could lower the albedo thru misting, thereby lowering the local temperature?

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