How We Do It: Make Water

“Water, Water, Everywhere, Nor Any Drop To Drink” the line from 'The Rime Of The Ancient Mariner' is the same quandary the modern mariner faces, until now. As we build our village at sea, we have modern technology to help us out.

At sea there is virtually unlimited energy and an unlimited source of water, we just have to figure out the best way to garner the energy and remove the salt from the water. To start, the phase one hotel barge has two water desalination units that run off of fuel oil that will amply supply the needs of those living and working at the town center, but we intend to use those only in case of emergencies once we get completely set up.

There are many ways to desalinate ocean water that would make it drinkable, but a lot of what we use fresh water for on land would only be wasteful at sea. As an example, there is no reason not to use the abundant salt water to flush and to clean with. No reason to take navy showers either, (where you get wet, shut off the water, soap, and then rinse and you're done). That may save water, but a long hot shower is important too; and with a little planning you can have both by using hot ocean water to shower with followed by a quick rinse with fresh water.

Anyone who lives on a boat knows that anything you can do to cut the power usage is helpful, even though there are a number of new tech ideas to help with that. On a boat there is also limited space so if you are spending days out away from a good source of fresh water, you will have to be able to make it yourself. The first source of fresh water is the rain. When the sun hits the ocean water it evaporates into the air so there is always a high humidity factor on or near the ocean. As that moisture cools, you get rain, and it comes down in bucketfuls. Depending on the time of the year, rain can supply most or all of the water that some people will ever need.

The next best way on a boat is a small desalination unit and a way to generate the electricity needed to run them. Most live-aboard boats have a generator to supply limited power, but not all, and the power supplies are limited. Cleaning water takes time and while you are using the water maker, there isn't much power left for other things. So a third way to make water is by distillation.

Actually the powered water makers use a reverse osmosis system for filtering the water, which is good enough, but distillation is better as it takes out more stuff than just the salt. Just like mother nature herself, you put salt water in a black cup and set it in a white bowl, you cover the cup with a clear glass cover like a 3 liter bottle with the top cut off then flipped upside down to create a transparent dome, the sun then heats the water in the black cup and the moisture condenses on the dome and runs down into the bowl all clean. The problem is that it takes forever to get a cup of water this way, because even on the equator the sun alone just isn't hot enough.

This is where modern technology comes in. Thanks to research at MIT⁰ there is now a graphite ‘solar sponge’ that creates hot spots on it's surface that makes steam with 85% efficiency. The graphite sponge is black and absorbs the sunlight across its surface while at the same time sucking up water from the inside holder. The steam is captured and cooled to make clean water, again with no extra energy usage.¹

The water making systems that have existed do so because the need for them have existed. No one was really living in the ocean full time, so no one ever made anything that would produce enough water for a modern floating house's usage. Until Dean Kamen took up the task, that is. He is a modern day Thomas Edison. He's the guy that made the Segway people mover and has saved lives with his medical devices. Now he is at it again with the 'Slingshot' water purifier.²

This new system uses the heat from the steam that it produces to preheat the incoming dirty water. By recapturing the lost energy, the system breaks all efficiency records. It is reported that a unit small enough to use in ocean homes would produce up to 250 gallons of clean water per day using no more energy than a hair dryer or about one kilowatt. No filters to clean or replace, and with few moving parts it should last quite a long time. After the saltwater is heated to the boiling point, the steam is put under presser which condenses the steam to a liquid that is heated past the boiling point. This super heated water is passed through tubes that act as a heat exchange and the heat is passed to the incoming water preheating it while cooling the effluent to room temperature for usage.

So if you are wanting to live an Amish style lifestyle with no electricity, living on a boat or full house float, there are already solutions to having all the fresh water that you would need. However, with rain, reverse osmosis units, distillers and the new Slingshot method, there is a way to produce clean water for just about every lifestyle or situation. But just because we can do it all now, that doesn't mean that we won't be constantly looking for the newest better way to do everything, we will. All to make ocean living the preferred lifestyle of the new century.

marinea.org / Bob Llewellyn / March2016

Revised January 2021