Solar Water Distilation
Daniel has created this solar water distiller. There are so many wonderful uses for something like this and my head is already buzzing with ideas inspired by this design.
Using this design you can take filthy dirty salty water and end up with drinkable water. Amazing!
Make sure to check out the whole project here, and use this space to leave comments about the project.
- Posted in : Politics, Positive Change, Renewable Energy, Sietch News
- Author :The Naib
Comments»
That’s a nice implementation of a great ancient invention.
I’m curious about the patent application. Since solar water distillation has been in (recorded) use since mid sixteenth century, there have been a lot of prior-art variations on the technology (reflectors, film-capture methods and the like). I even remember a Hardy Boys novel from the 60s? where they built a reflective solar still from a hubcap and saran wrap.
What do you see as new and (hopefully) patentable with your particular still?
Hi Maxwell,
Thank you for the question.
I agree that solar stills have a long and innovative history. The physics are well proven, and nearly any method to capture evaporated water (like your Hardy Boys example) will yield some amount of purified water.
Nevertheless, solar stills are and will continue to be more of a hobby than a business until the cost per liter distilled fall, or the value per liter distilled rises. I believe that my design improves both the cost and value aspects of the equation.
Once you start investigating the specifics of this design, there are not that many solar stills that use a parabolic trough to concentrate sunlight (most are box stills)…principly because making a large parabolic mirror is usually expensive. My mirror is cheap.
1) I believe that my method of forming a parabolic mirror is unique. The clear aperature of the mirror is entirely unobstructed (aside from the frame) and uses a stable tension/compression balance of forces to maintain its parabolic shape. The combination of wire and strip/frame form a natural parabola.
2) The two piece evaporator design allows one to flush/clean out the water evaporation pan to prevent scale/salt buildup (even using “dirty” water) without compromising/contaminating the condensing cover.
3) The device is lightweight, portable and can be stored easily.
4) I could not find anything like this anywhere, including a careful search of previous patents.
Ultimately, I lose nothing (aside from the application fee) by applying since I will either get a patent or I won’t. And I’ve spent a lot more on numerous dead ends before arriving at this design. If I don’t get a patent, I will be highly confident that a large company cannot prevent me from making my solar still.
I believe that clean water supply is a critical issue for this planet, and feel this is one area where a clever design and some persistence could create a solution that many people already need.
Physics is not my strong suit but I have often wondered if you could set up some kind of system at a coastal region to cause solar energy to heat sea water to vapor, warm the air and allow it to follow an insulated pipe up a gradient to a region where the pipe was not insulated, allowing the water to condense and flow down a second stretch of pipe to some location. The cooler (now more dense) air and water running down the pipe would hopefully create a draft pulling more warm moist air up from the sea. It would effectively be a version of the water cycle but directed to a more specific location. Instead of a reservoir in this device, it might be a pipe running through a series of similar apparatuses. Several in a “farm” could be hooked to one large pipe.
In many cases, deserts are caused or aggravated by a “rain shadow” of mountains. Might such a system provide a means to not only desalinate but also transport water to such areas? Does anyone know if the feasibility of such a scheme ever been examined?
Hey–if you could figure out a particularly efficient or space-saving way to hook this up to a rain barrel (see http://www.aquabarrel.com), I bet you could get that combo itself patented!
Saul Wall,
I don’t know about any projects on the scale you describe. A couple years ago I heard about a small firm (I believe they were at U of I Champaigne) using physics related to your idea in reverse (i.e. input warm/humid ambient air into a series of pipes that go into the cool ground such that the moisture condenses and runs down to a storage area–you can then pump the water out as needed).
While I have no idea about what has been studied for feasibility in the past, my greatest concern with your idea is how far along a pipe you expect the evaporated moisture will travel before in condenses. 10-100 meters (30-300ft) seems possible. 1000meters seems unlikely. Greater distances very unlikely…not saying it couldn’t be done, just doesn’t sound that feasibile.
Lara,
Neat idea for collecting rainwater…are you thinking that a person might use the aquabarrel to feed water into the distiller or to store the distilled water?
Would you be willing to draw up a diagram of how this works? I’m not clear on what part is what and how it all fits together. I’d like to try making one.
This is very cool. Thanks for reporting on this idea. I’m planning on linking to this article from my website. (www.innovateenergy.com)
just an idea, if you used glass as your collecting trough instead of plastic, the temp on the walls should be a bit less or if you attached the cooling pipes from the back of an old broken fridge to the plastic trough box and put some dirty water in there with engine coolant it might make the plastic a little cooler for you.
I believe that some kind of solar distiller would be great for producing cheap biofuel — ethanol. The most expensive part of producing ethanol is distillation, if one could use solar energy instead of biomass / fossil fuel, that would make ethanol even more renewable. :)
The idea is simply good. I am from India from a region where pure drinking water is scarce and costly, Madras now renamed CHENNAI.
Basically i am a mechanical engineer doing my master in Thermal engineering. Currently i am pursuing my project work.
and yes i have the same topic of ur intrest as my project topic
and i would like to have ur guidance in this topic as u have already a vast experience in this area.
Great idea, Daniel, wishing you all the best with it.
Assuming no lack of dirty water, it occurred that you might enhance the cooling effectiveness of your condenser with the dirty water flushing over a thin evaporative mat attached to the exterior of it, thus providing evaporative cooling to it. The overflow from that, what’s not evaporated, might then next be routed into the unit to keep it topped off or feed a trickle flow chamber that would regulate the flow. A bonus may be found in that this overflow feed water might then also be pre-heated somewhat, especially if regulating flow chamber is blackened, reducing the net solar heat gain required later inside the unit. A small solar powered pump could be used to move this dirty water or simply a gravity feed with a larger barrel of dirty water positioned higher near by.
would you sell one or three of these units
Thanks for all the helpful suggestions.
Krzysztof: A significant fraction of the public that I explain this idea to always wants to make booze (lol). At least in the case of ethanol people (shouldn’t) drink it, so the fact that you expose it to all kinds of sunlight maybe won’t stop the conversation.
Ramanathan: please contact me (or post on my blog) with any questions or problems that I might be able to help you.
Tom G: I appreciate your suggestion. Glass would transmit heat better than plastic, and any way to flow water over the plastic cover should also increase cooling & condensation.
One objective I had was to make a light-weight and portable distiller…I am a little afraid of using glass since it heavier than plastic and more liable to break in transit.
Flowing water through some piping or tubing is certainly an idea I’m considering. I will have to add complexity in terms of adding a pump, a power source to drive the pump (a couple solar cells?), and decide what fluid to circulate. I would hesitate to add engine coolant to a water distillation system…just too much (user) education and liability issues if someone put water where the coolant goes or vice versa.
Shane Connor: Excellent idea. I’ve been thinking about flowing dirty water (through a tube) over the fins/cover to lower the condenser temperature (and preheat the water), but had not considered letting some of it evaporate or using a mat/spongelike surface to increase evaporation on the outside of the device (i use sponges inside to increase tha air/water surface area-and hence water evaporation rate).
Mark M: Yes I’m interested in selling units. I feel that this is still an R & D project at the moment. I believe I can implement some tricks to increase output markedly, but if a gallon/day is enough water for your application we should talk. I’ll send you an email off-line to discuss.
Hi,
This is indeed a very interesting product.
Would also like to test a couple of units.
Working for a charity in Kenya.
Please drop me a line.
Cheers,
JC
Try to cover the distiller zone (upper transparent plastic) with a mirror or white paint, to avoid the direct sun light and decrease the temperature, and I think that some vibrations in the distiller zone will help to join the water cells and help it to fall.
That’s a good project.
It will be usefull in the future…
CL
Hi Daniel! Finally found someone working at a scale that seems reasonable. In the U.S. it seems that most products are either on the cheesier end of the spectrum or hopelessly complicated and expensive. If this one can be scaled up to two gallons to four gallons a day and kept simple to operate, I think it would be marketable in this country in the near future. One suggestion that would up the cost but might help the concept: An interchangable glass cylinder inside a darkened glass sleeve for a condensate chamber. The darkened sleeve would be out of contact with the purifying water and could be rotated on its axis around the glass cylinder. Rotation might be able to accomplish two things. First, the amount of light coming into the chamber could be altered and change the temperature of the chamber. This could extend the seasonal usefullness of the device. (hotter in winter, cooler in summer) Second, If the sleeve were rotated all the way down, the glass tube could be pulled out without dripping water onto the reflector. A second tube could then be placed in the device while the first tube was being cleaned and sterilized. Just an Idea. Good luck!
Hi
My name is Arseeneh from Armenia , now I am studying in Yerevan State University .My research is about water (Physical chemistry properties and reactions in diffrent grade of water ).I need to large information about water ,for example What kind of reactions can ocurr in diffrent water(drinking water,……………..).
Can You help me ?
Would it be possible to post more photos of the actually distiller? I would like to experiment with this idea, but I am confused as to how to actually put that part together.
hey daniel
neat idea…that was really very impressive
could you suggest some more methods for water distillation that you think are feasible on a small scale???
i am an engineering undergraduate and have taken up a similar topic for my projectwork.
i’d be grateful to you if you could guide me in my endevour…
thank you…
Hi Daniel
Congratulations on a beautiful distiller. Water evaporates from about 50 C, so lower temperatures from a smaller trough not a problem. If the distilled water collection point has some zeolite in it, or other hydrophilic material such as coconut fibre, then the amount of water drawn off is slightly increased because these materials attract and hold water molecules on their surface, and drip. Even some coarse grain sand might help. A black pipe on the surface of a tidal zone can capture water at high tide and ’steam off’ to a water tight container thats buried under the sand. Ofcourse this relies being stuck on a desert island with nothing else to do except float black plastic pipes around a rockpool…… Good luck with the project.
how do you construct the sea water solar desalination step by step
Great post. Just a thought on tracking - rather than use a motor, which would require electricity and complicate things, couldn’t you take advantage of the transfer of water from the “in” container to the “out” container to slowly rotate the mirror over the course of the day, at a rate that roughly tracks the sun?
Use the cool incoming water to cool your condenser. This will slightly pre-heat the incoming water and help raise evaporation rates, which should increase efficiancy.
Hope this helps
Tom
very interested in having one we live in the florida keys we drink bottled water now and we live in a hurricane zone and the fresh water is pumped in about 90 miles and doesent tast to great would really like to have one or two of your systems. i hate to rely on piped in water since it has broke a couple of times and water sells out of stres very fast . please help us out mark from the keys 305 394 0987
Excellent Idea! I to have got some projects under way. Email me if you want to discuss applications.
hi daniel,
great idea ,i didnt understand how the evapourated water is collected .will u please explain?
can u plz send mea scatch diagram of solar water distilation for desalination?
yours thankfully,
abhinav(INDIA)
Thanks for being willing to share this info online. I also was going to write about possibly using this idea on a larger scale for seawater purification, but greater minds than mine have already expanded the idea far more than I could have. There have been major droughts on both coasts in recent years and that seems like quite a shame in a country that we like to consider *so advanced.* I’d suggest that as well as selling the patented device you could also patent and sell plans. I’d hope you’d make it a nominal fee so people like me (the ones who really need to make one) could afford it. But in that case you wouldn’t have as much access to other people’s input as you have in this forum. And one question: is there any significant danger of the mirror being a danger to lower flying air traffic — such as the medical helicopters — that seem to be becoming more prevalent these days? I can’t help but wonder if a mirrored gadget pointed at the sky would scare the neighbors and/or Homeland Security.
I have been thinking of this kind of thing for years. I have thought of a version that floats on water, perhaps floating in tidal electricity power generation pools.
Would love to see the plans.
CONGRATS DANIEL. REALLY IT WILL BE A GOOD SOURCE OF WATER FOR A WATER SCARCE COUNTRY LIKE INDIA. I WOULD BE VERY HAPPY TO SEE THE PLANS…….
This method certainly separates water from solids, germs and contaminants with am evaporation temperature much higher than water but, how do you let volatile contaminants escape? Some of them will condense back together with the water, as it happens with the solar stills.
I would like to learn more on the science of distillation columns to see how this could be applied to a solar system. May be your mirror invention’s high temperatures will work better than a solar still, but you will need to find a way to let volatile solvents to escape so that only water condenses back.
please tell me where this plastic mirror material is avaliable..great article
tom black
Great invention! I´m Nicolas from Argentina. I´m a teacher and I´m planning to teach my students how to build energy-smart devices such as yours (a lot simpler, of course) in order to teach high-school students about green energy. Could you send me more detailed information about it? (no commercial use guaranteed).
Besides: Do you think a larger scale device (say truck size) could power a small stirling engine with the extra heat? that would solve the “extra heat” issue, the water pump needs to circulate water, and maybe power a small energy generator, needed in most water-scarce areas. It would take the simplicity out of the system, tough…
thanks, and congrats!
Increase the surface area on which the water condenses, and you could eliminate the cooling fins
Hi, neat project.
You may want to look into heat pipes to aid in condensing. Butane or a common refrigerant would work well for the temperature range you’re operating in. Also, aluminum instead of acrylic might be workable, just wouldn’t be able to see inside that well :)
I second (or third) the comments about using cooler incoming water to aid in heat rejection. Running a thin (1/4″?) pipe from a cool, dirty water reservoir through the condensing area and then into the evaporation tank would increase efficiency. The cold would aid in water condensing, and the heater wouldn’t have to heat up the water as much.
Here’s a website that shows a plan to do something similar on a commercial scale:
http://www.solardesalination.com.au/
I like your low-budget alternative! One possible improvement of your design would be to focus the rays on a smaller, black metal pipe (which draws in dirty water) and then collect the resulting water vapor in a distiller off to the side of the collector. A tube travels upwards a short distance from the far end of the heated dirty water pipe, and then you spiral the tubing down into a collector. As the water vapor cools, it condenses into pure water. You may have to clean out the heating pipe occasionally, especially if using salt water. If you had a long line of mirrors, like in the photo, the brine could flow down as the water vapor travels up, and the brine is then discarded or allowed to evaporate in the sun to collect the salt.
Great project. I have been developing a few solar distillers and encounter the problem with cooling the condensation coil without the use of a fan or cooling water. How are the VOC’s in your unit released?
peace & love,
ariel
I see a design flaw that if you fixed would add that missing capacity that you should be getting in theory.
the cooling fins are exposed to the sun and if my math is right they are actually adding heat to the condensing section. a simple fix would be to add a sun shield around the fins and condenser to encourage them to radiate heat even goin as far as adding a solar powered fan to blow air between the sun sheild and fins/ condensing unit
I concur with my compatriot Nicolas from Argentina: great invention!
I live in a small village with an unreliable and non-potable water system. Municipal government couldn’t care less. I built a super-insulated straw bale house here, and now, three years later, the viIlagers are starting to show some interest, though they are still skeptical. I would greatly appreciate plans that would make it possible for me to build a “home” version of your invention with the hope that interest can then be generated for a community-scale project. No commercial use intended.
It’s wonderful design than I ever seen, Daniel. By the way, can I get your design to complete my research reference ? Thanks a lot
Hi Daniel,
Have you ever thought of using this device or a similar device to simply speed up an evaporation process? We have a commercial tank truck wash at a property that has no municipal sewer system meaning, all of our waste water ends up in our “sewage lagoon.” We have been looking for ideas on how to get our lagoon to evaporate at a quicker rate because it fills up to quickly. I think there is a market for this right now.
Hi Daniel,
Congratulations on a beautiful portable distiller. I want to know how exactly the distiller unit works. Please send me some markups or info.
Regards,
Sandesh
DANIEL - Thanks for showing us this great design for a concentrated solar still. It is along the lines of what I have been thinking, but it is nice to be able to see this model that actually works, rather than one in theory. A big advantage of the concentrating reflector is the higher temperatures, which have the potential of killing bacteria. Many passive designs are not distillers at all but are merely low-temperature evaporators and are not capable of neutralizing bacteria. I like Ed Stamm’s idea of using a black pipe, with water travelling toward a separate condensing unit. This might result in even higher working temperatures. I am grateful to Eric for bringing up the problem with VOCs. He is thinking of using distillation columns to further purify the end product. I really like your idea of using Mylar film to form the parabolic reflector. There is another technique for making inexpensive parabolic reflectors, which I read about while researching Sterling Engines and refrigerators. One old design was to stretch a mylar skin over a framework like a drumhead. Then, if it is sealed off and a vacuum pump used to suck out some of the air, a paraboloid results in the surface(s). So, this is another inexpensive way to make a solar concentrating reflector. Your design might even be simpler than this, especially in smaller sizes.
Here is an angle that has not been addressed yet. I noticed that several comments are posted from other countries that have a contaminated water problem, including India, Argentina, Kenya. As a matter of fact, much of the world has a contaminated water problem. One thing many people in the U.S. do not consider is that there is a potentially serious problem here that much of the rest of the world does not have. The problem is just now getting recognition, as a primary cause of hypothyroidism in the U.S. It has reached epidemic proportions and the leading suspect is fluoridated drinking water. Iodine and fluoride compete for the same space in the thyroid gland, and fluoride is more common that iodine in many people’s diets, with 4ppm fluoride included into our drinking water at the purification facility. Fluoridation solves an important disposal problem for the fertilizer and aluminum industries, since they can charge the water treatment plants for the waste product, which used to be an expensive byproduct for them to dispose of. The first company to experiment with fluoridation of water was I.G. Farben, for the purpose of crowd control in prison populations during WWII. The original purpose was as a “soft lobotomy” to the prison population’s brains, rather than strengthening dental enamel. The real victim is the thyroid gland. There is another reason why your design of a concentrated distiller is so timely. The internet is full of information on the fluoride/thyroid connection and here are some links. There might be a large market for this distiller right in the U.S., until fluoridation is ended.
http://thyroid.about.com/od/drsrichkarileeshames/a/fluoridechange.htm?nl=1
http://thyroid.about.com/cs/toxicchemicalsan/a/flouride.htm
http://thyroid.about.com/cs/shames/a/fluoride.htm
Gary
Great idea and well thought out.
Just 2 points:
I would forsee the length of the trough not always being in direct sunlight, thus cooling part of the dirty water.
Surely you could extend the black base to either side thus preventing light being reflected onto the clear cooler plastic parts (condenser). This black base could be made of a conductive copper thus increasing the heat generated at the base.
Dear Mr.Daniel
Have a Nice Day
i would like to say COGRATULATION, and to Thank you for your Faithful Efforts.
This is your Friend Mr. Mahmood S. Majeed from IRAQ, Basrah City.
As we have a Big problem of the High salinity Water and need to do a Big disalination wrk to achieve a huge quantity of Drinking Water for Human , Irrigation of our Small Garden ,
I am studing your Idea/ project and try to apply the same practically.
So i need to recieve your ACCEPTANCE to do That as it is you idea / Patent and i will not start unless i recieve you Reply
Thnaks again, Best Regards
yours
Mahmood S. Majeed
Basrah, Iraq Alfaw District
E mail: annajah1989@ayhoo.com
Mobile: +964 - 7801390939