Solar Ice Maker

Tried hunting through the 'ables, and also hunted for it elsewhere. Has anyone done an Instructable on making a Solar Ice Maker? And if not, will anyone do it? I've got some ideas for trying to use it as part of a home cooling unit, but I don't know how to make it yet. Thus, modifying it seems kind of out of the question. Thanks for any help in advance.

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KarelK83 months ago

Nice thread. Researching this stuff now cause I live on an island without drinking water and my guests keep asking me for cold beers! http://www.islandhoppinginthephilippines.com/palawan/patoyo-kitesurfing-eco-resort/ So far have found I can add a 1700W wind turbine for $400 to my solar system (through the regulator, because not sure if the 100W solar panel will suffice) to connect with a $600 12V -13C freezer I found on ebay. But would be nice to find a more organic and cheaper solution. One German guy passing through put a thick black cotton sock over the beer and wet it with fresh water. Said it reduced it by about 10C sitting in the hot sun evaporating.

DavidN711 year ago

You can buy 12vdc compressor based refrigerator/freezers that run directly from solar panels. They are quite expensive, but common in the medical and forensic fields where preserving specimans or medicine is worth the up front cost. The cheapest 40 quart 12v fridge/freezer is about $500.


rantonio31 year ago

You may want to check this out http://www.slideshare.net/zacoss/solar-ice-maker

sansenoi4 years ago
High tech just for ice? Forget the ammonia and zeolite and methanol and activated carbon and solar panels and stirling engines and solar reflectors and.........etc, if you can afford it or understand it. Face it, the only time most people will get around to making one of these is when it is necessary and that means that exotic materials or time spent making parts means you don't have ice.

If you want to make just enough ice to put in an icebox to keep food cool, you need to make it in block form rather then small chunks, it thaws slower that way.

All the above being said, if you hook a rotary vacuum pump to a bicycle that hooks to a strong walled vessel mostly full of water(less air to pump before it starts to boil) you can pedal at a leisurly pace for 30 minutes to an hour and get about a gallon of Ice to sit in your ice box. More water to freeze= more pedaling, higher water temp=more pedaling, small moving volume pump=more pedaling.

Hook pump to a decent water wheel on a good grade stream or a good sized windmill (enough to overcome torque) and voila. All this with no exotic solutions. make multiple vaccu-tainers with water and swap out when one ices up.

You only have to have a strong/expensive enough vacuum to make the water boil, once it starts boiling the pressure can, if you want, stay the same in the chamber due to vapor expansion leveling out the vacuum. A pump rated just enough to reach that point vacuum with a large moving volume will work but if you want to do it quickly you want a vacuum pump that can remove the expanded water vapor much faster than it is created to get faster boils/higher vacuums and thus less pedal, water wheel or windmill ice generation time.

Make your water ice cooling chamber easily disconnectable from the pump and place it directly in the icebox. That is unless you want ice cubes, lol.
Tawnas sansenoi2 years ago
Apperently you know the subject quite well. I am puzzled why my zeolite is not adsorbing any vapor. The water boilled at 28 in hg. i shut the vacuum pump at 29.9 in hg after i closed the valve seperating the pump frm the system. then i opened the valve between water and zeolite granules. the pump gauge dropped down to 24 in hg and stayed there overnight. The water level did not go down in 12 hours indicatig no adsorption took place. i then baked the zeolte for 3 hours at 425 F and repeated the process. The water stayed where it was and the zeolite stayed dry. Any idea what mistake i could be doing? I also ran my 5 cfm vacuum pump wihle keeping zeolite sepated. In 5 hours of pump time my 16 oz water got down to 42 F. The vacuum gague indicateed the system has zero leaks. Appretiate help
At first It seems a bit far to make ice within a vacuum. But apparantly if the videos are real on you tube. you can. Using the zeolite, ammonia for whatever is passive so they require per se no moving parts. doing the boiling method requires a bit of energy. Correct me If I am wrong.
Dear Sansenoi,

Do you have any more detailed plans you can share of the one you built or someone who has built a similar one? We have a children's home in the jungles of Belize and would like to see if we could build one. Thank you for your help.
Sorry for the delay in response. I have been away for a long while. Although you probably have already found your answeres and moved on, I will leave some more info in case you haven't.

There is not anything more detailed as far as construction plans than hooking up a vacuum pump to a well sealed container. Some things I need to clarify though is:

1. you need to understand that if the water is vaporizing, you need to start out with more water than you will need. Water from a stream or well is fine if you are using a sealed chamber to hold the block from leaking untreated water and also, water with high minerals such as salt will take longer to freeze.

2. If you pull a proper vacuum fast enough, you'll just end up pumping out all of your water in vapor form before the remaining turn to ice again, remember to insulate cooling chamber with a sleeve while doing this to help.

 3. IF you want to make a zeolite and water fridge before you actually need zeolite in an emergency, zeolite can be had from pet sores in two purities with different prices. Look for bulk containers of pure zeolite based Ammonia remover for aquariums about 9$ for 6 pounds (enough to make a normal colemanish size ice box unit, just cut small U-cut in top of chest lower half to slide the ice end of unit into and close the lid over) or single ingredient zeolite based non-clumping cat litter that is in newer types of litter. I found mine at Home Depot, about 25$ for 25 or 50 pounds if I remember.

 4. A zeolite ice maker is much like what I described in my original post. You just have two containers, one for zeolite and one for water with a vacuum rated valve on a pipe in between that has a hookup for a vacuum pump. Reduce the pressure to that of the sublimation of water at around 45-60 deg. F and remove vacuum. Some water will be drawn into the zeolite taking the heak and the water left behind will be cooled or frozen. Stick the cold end in the icebox. When thawed, heat the zeolite end( (above/below water end, depending on your desing. Design may need two connecting tubes w/ valves having 1 tube running to the bottom of the water end resevoir so when you heat the zeolite/water mix on bottom, the water distllls out without running back down into zeolite)) to around 180-240 deg. F for at least 2 hours to recharge. Having vacuum/pressure guage attached comes inhandy, if no leaks it will let you know(after cooling) if it got all of the water out of the zeolite.

Remember to tun all valves after recharging off until you want to use the unit. Slow leaks will ruin the unit after you may not have access to a vac pump to fix.

Make sure you put a mesh or other sort of trap to prevent migration of zeolite to water end. Capped pipes drilled with small holes, surrounded by zeolite, sunk into the zeolite container end and attached to the valve pipe works.

Experimentation for your unique setup is needed for best results.

I have no plans or designs to outright share. Only advice and material sourcing on zeolite.

P.S.- don't unerestimate the reliability of a small gas powered "einstein cycle" closed loop ammonia fridge as used in modern day RV's. You can get these pretty cheap from old scrap yards or by removing old campers people just want to get rid of or scrap. (no, I'm not talking about the big fridges in luxury RV's, I mean the minifridge type like Elmer Fudd would have in his Rabbit hunting teardrop camper)

With some modifications you can make one of these run from a not so large fresnel lense or solar array during the day, store excess heat in heat sink for night or run on just about any small heat source if you're careful.

As for me, I went with a temporary emergency water/zeolite setup made prior to any need. If it would fail for some reason I could always just use the vacuum pump used to initially prime it but daily use would wear it out quick over a long term situation.

I also learned to use natural dehydration and Lactic acid / acetic acid preservation techniques that require not having to buy vinegar or starter cultures beforehand or the need of a pressure cooker/canner ( (now just relegated for distilling water and "other" liquids)) to sterilize anything since the good bacteria keeps bad in check.Cabbage Kimchi is really good, especially made with fish or shrimp but you could also use trout, Deer meat or even grub worms if you really wanted to! Except for storage of non-replenishable long-term freezable,s I really don't worry about any daily and long term need for refrigeration anymore.
Edit note.. # 2. above should start out, " If you don't pull a proper vacuum..."
your thinking is really great.any ways you had done a good job.i really appriciate you.
Thanks, sorry for the delay. If you have your notification emails on to get this response to you, you might want to read my Sep. 24, 2013 response to another person asking for details on low tech ice. I.E.- Look above this on this instructables page. lol
kkbhanot2 years ago
Come across this post and an ebook http://confusedhowto.info/solar-ice-maker-solar-energy-projects-for-the-evil-genius/
If you have seen Back to The Future 3, the Professor Dr. Brown has an ice maker back in the 1800's. Seems simple enough. I'm sure you techies can make a working replica easy enough.
sansenoi4 years ago
Oh, one last thing, put your boiling chamber in a insulated chest with little air volume, you don't want to have to keep pedaling to remove the heat absorbed through the walls of your ice forming container while lowering it to freezing.
I know this thread is long abandoned but you are looking for an absorption cooler. These are used in campers and RV's. They use propane but you can use a solar collector just as well. And on your collector, look into fresnel lenses. They are cheap and you don't have to spend forever focussing them like you do with mirrors. Best of luck.
jmrock5 years ago
Anybody here in NW Montana interested in building one of these? Kinda funny but seams really simple to construct but I've never seen one built outside of Central America. There I seen 3 of them but didn't quite understand them at that age.
I'm in Missoula. Building one of these to take with me to Burning Man. Want to put our heads together?
I'm having trouble locating the flexible mirrors they used in the solarice.PDF.
Any ideas?
Have you seen this one?
solarice.pdf(585x783) 346 KB
guyfrom7up8 years ago
I forgot where I saw this... but: you take a large black pipe fill it partway with amonia. the sun causes it to turn into a gas at night it turns back into a liquid, cooling water near it. you then have ice in the morning google around
found that at an E-book called "solar powered projects for the Evil Genius" w/ the word "darksiderg" somewhere around that. Find it at "www.mininova.org" I guess that's the site.
There is also something similar to this used in propane refrigerators.  Basically, there is ammonia dissolved into water.  Using heat from a propane flame(easily replaced with solar) the ammonia is boiled out of the water.  It is used as a coolant and is circulated through the system.  At the end, the now warmer ammonia is exposed to unheated water.  It wants to dissolve in water so much it actually releases its stored heat to allow for it to happen.  Rinse repeat.  I don't understand it completely but this system does, as part of its design use heat to create a cooling cycle.
Ammonia was among the first refrigerants used and in most places it is illegal to use as a refrigerant nowadays. Ammonia does work though.
Could anybody cite where I would find the laws regarding the legality of ammonia use as a refrigerant? I too am very curious about this instructable.
i read that too!
kcls6 years ago
Heh. I couldn't stop laughing when I saw this. It's so ironic! Solar. Ice. I never even thought the two could be used together in a sentence! I didn't get it at first, but then I thought about it and understood. Thanks man, you just made my day.
RelientOwl6 years ago
I got kind of puzzled at the title they're like two different things
There are a lot of ways to do this you could, as forgesmith said drive an electrical or mechanical AC/fridge unit with solar energy. You could also consider using peltier or other thermoelectric units to remove heat from the cold box these are however more suited to simple cooling, a 12V mini fridge could easily be modified to your purposes but it wouldn't be great at ice making without some modifications and overclocking of the peltier. You could use wind or water power very effectively instead of solar to make a nice unit that runs a compressor and/or a generator, the compressor of the AC unit giving you your cold with zero electricals... Another good option may be to run a stirling or steam engine of a solar heater, if you have a lot of sun energy you could make a parabolic dish to run a boiler that would power a steam engine, this would be a nice way to get rotary power for both electrical and compressors, using a generator you could run electricals of of that, also a good efficient steam or stirling engine setup is much more efficient than a solar panel, to the best of my knowledge.
Grey_Wolfe (author)  killerjackalope8 years ago
I've thought about going with sterlings for electricity, actually using the parabolic dish to make the sterling work better. (pretty sure that's more efficient than steam engines.
If you built a good Stirling engine, yes it would be more efficient but well built is the key here, the parabola should be comparatively easy...
Grey_Wolfe (author)  killerjackalope6 years ago
I have a left over sat dish in my shed. So the parabola is pretty much a prefab.

I have yet to come upon the most effective sterling design that I could manage cost effectively, but I am looking at such designs for a larger power plan than just a freezer now.

I was interested in figuring out a design that might get away with using basic thermodynamic principles and heat transfer to create the ice here.

I figure if the energy doesn't have to be converted it should be more efficient.

I understand the principles, it's putting them into design that seems to have me stumped at the moment.

(Pardon the late response, it's been a busy few years. lol)
ajparag6 years ago
i have some information to share. please go to the below link to check out the site. these guys are working on a similar project.


and download this file from there:

Study, Design and Fabrication of a Solar Powered Adsorption Refrigeration System
kramerr6 years ago
In physics we have this nice relationship called the perfect gas law:<br /><br />Pressure*volume = moles * r * Temperature<br /><br />where r is the gas constant: 8.314&thinsp;472(15) J&thinsp;K&minus;1&thinsp;mol&minus;1 <br /><br />In simple terms: When you heat a gas it expands. If you force a gas to expand without adding enough heat it will suck up heat from everything around it, producing a cooling effect.<br /><br />Try it out for yourself by empting a can of compressed air. The can will become cold.<br /><br />Its because of this relationship that the evaporation of sweat cools us down and fridges work by compressing then expanding a gas.<br /><br />An ancient way of keeping drinks cool was to use pots with very small holes. As water left the holes it would evaporate which would cool down the pot. In theory a temperature drop below the freezing point could be produced in this way if something that evaporates quicker than water is used. <br /><br />I think amonia might be suitable if you put it in a near vacuum.<br />
Plasmana8 years ago
A solar ice maker???
A solar ice maker???
It takes energy to make ice, the sun is a source of energy. The rest is engineering.
Oh, I get it now, sorry for being stupid...
Oh, I get it now, sorry for being stupid...
Heh. Bud, if everyone felt sorry every time they did something stupid, the entire nation would have to be on prozac to get anything done. Don't worry about it.
fav comment ever!
Grey_Wolfe (author)  forgesmith8 years ago
You mean it's NOT? lol There are no stupid questions, Plasma. Some are very close, but I don't think that one was.
Okay, thanks...
Pretty easy, you will need a large quantity of dry straw, a shallow pan and a desert. Use the straw to insulate the pan from the earth, fill the pan with water and wait over night.
Grey_Wolfe (author)  Tool Using Animal8 years ago
Ok, I know what's going on with this one, and it makes sense (assuming air temp drops low enough). But I'm confused as to how it's solar? Wouldn't the solar ice maker actually work better during the day?
call it an anti solar ice maker then...
Grey_Wolfe (author)  Tool Using Animal6 years ago
I wish I'd cauth this comment earlier. It was pretty funny. :)
TaffGoch7 years ago
Looks like all the development work has been done already. There are several firms that are starting to produce turnkey products based on this 'how-to' article:
Grey_Wolfe (author)  TaffGoch7 years ago
Thanks. I've seen the picture before. Seems kinda big for a bit of ice though. lol It's all about the engineering though.
V-Man7378 years ago
in rethinking your question, I feel my sputterings about inverters and batteries with huge duty cycles missed the mark. So, after a Google search, I give you a couple resources that look promising: This PDF to HTML document (scroll down) seems to cover what you're asking about, and a closely-related (albeit strictly trademarked) model called ISAAC.

Apparently all you need is a refrigerant such as (distilled!) ammonia, dissolved in salt, in the "generator" of the sealed system (the "generator" is where the sun heats the solution). The PDF calls specifically for calcium chloride. As the sun heats up the solution, pressure in the system increases. The ammonia escapes in vapor form and travels through condenser coils to a containment tank (which will soon be very cold). When the generator no longer receives heat, the system cannot maintain the vapor ammonia, and it is "drawn" back to the generator component as the salt reabsorbs it. This absorption lowers the pressure of the system, causing the ammonia in the tank to evaporate, drawing immense amounts of heat with it. Water is placed close to the tank and loses all its heat - voila: ice!
Grey_Wolfe (author)  V-Man7378 years ago
Thanks, bud. You've been very informative. Thanks to everyone else for their insights as well.
forgesmith8 years ago
Part 1: Use solar power for mechanical energy. That could be a Stirling engine driven with a parabolic mirror, hot water solar panels driving a turbine, or photovoltaics (solar cells) driving an electric motor.

Part 2: Use mechanical energy to drive an automotive air conditioning compressor. If you are careful you can liberate all you need off an old car, then build a styrofoam box for the core that was inside the cabin giving off the cold, mount everything and hook it back up, refill. Make cold.

Now when you consider the mechanical energy required when driven by a car engine, both the amount needed and the rate it must be delivered to the compressor, you can see the amount of solar-absorbing surface area needed, ballpark figures, is a softball field.


You set up some photovoltaic panels, add a good-sized battery and inverter for homebrewed solar-based electricity, and plug in the refrigerator or air conditioner.

Ah, and now I see why there are no 'ibles on solar ice makers. That'd be a single-purpose dedicated system, they prefer flexible designing around here. With the solar electric you can also recharge your iPod.

according to the interwebs, Fridges usually take between 200 (those really small fridges) to 1200 watts (big daddies). To get the inverter to run for 24 hours on a 12-volt battery (adding a 10-hour charging cycle from the solar panel) , you'd want a battery that can supply 4.8 to 28.8 KWH, or about 400 to 2400 Ah. I'm seeing a ceiling of around 20 Ah on heavy duty batteries on eBay, so to satisfy that demand, you'd want to hook in parallel 20 to 120 of them. (Am I figuring this out right? That seems a little outrageous.) I used to work for a company that had a UPS system running on about 100 car batteries all hooked together.

(A quick eBay search later) eBay has several machines dedicated solely to producing ice: this model is rated at 310 watts; here is a 150-watt model. Now that I think about it, you won't be wanting to make ice cubes 24/7, right? This could be simpler than I thought earlier... At 20 Ah (240 Watt-hours), our heavy duty car battery would give the inverter just enough juice to power the 150-watt model for about an hour and a half. According to the stats, that's probably enough to make around 2 pounds of ice. :-) Add another battery, and you can get 4 pounds.
I've yet to read about a commercially-available whole-house solar system that needs over twenty batteries, thus 120 seems very unlikely. Even twenty sounds high. So something must be off.

Whoa, now here at eBay-Australia they have 1050 Ah batteries for a solar system! Makes these common 86.4 Ah ones look puny.

1050 Ah... You could power an electric submarine with those babies...
I wonder where I'm going wrong... Is it my math? 20 Ah at 12 volts = 240 watt-hours... Meaning it will drain completely under a 240 watt load in one hour... But daaaang, 1050 Ah... If you got three of them (4v each) to make a 12v battery, then you're looking at a 12.6 kWh capacity. With that, you could run 525 watts for 24 hours. That sounds about like a moderate fridge.
Still... What's missing in my previous thought? How many watt-hours do solar homes use? For that matter, how many would a simple ice machine use? (I am now assuming one would not want to make ice 24 hours a day...)

Perhaps, do inverters change the rate by which power is drained from their sources?
. "Fridges are an intermittent load. They run for a short while and then shut off. Sounds as if you may have done your calcs with the compressor running full time.
>_< OHHHH that's why the yearly ratings on fridges are so low! Lawl. So we could consider the running wattage as a part of the average power time, just a surge area. Two questions from this, then: 1) How often, and for how long, on average, do fridges run? 2) Do fridges consume any power while not running (per se)?
2) Do fridges consume any power while not running (per se)?
That's somewhat easy. A dorm cube has a simple mechanical thermostat, only the compressor uses power. Once you get to a refrigerator / freezer, at the least they have a small heating element on the front between the two sections, you can feel the warmth on that surface the doors seal against, iirc it's to prevent condensation. I've found them on freezer-over-fridge, don't know about others but I'd suspect the same. Then there is the circulating fan, I can see that they'd have models that'd run the fan to cool the fridge from existing cold in the freezer without turning on the compressor until the freezer needed it, although with the old models I'm familiar with the thermostat is in the fridge and the freezer uses airflow controls, compressor and fan turn on together. Finally we get to automatic ice makers, standby losses with electronics, and the ultra-fancy drink and sushi dispensers, whatever they toss in these days.

1) How often, and for how long, on average, do fridges run?
That's math. Take the nameplate ratings for amperage and/or wattage, that's the maximum running amounts electricians need to know to size a dedicated circuit. Then see what the big energy use sticker gives for annual usage, been awhile since I studied one, if they don't outright say how many watt-hours then you can calculate it from the operating cost divided by the cost per kWh given. Divide by hours in a year for average watts per day, divide that by nameplate wattage and multiply by 100 for estimated percentage of run time during a day.

Heh. My parent's fridge I bought used as a quick replacement almost twenty years ago. It's a Kelvinator, made by AMC, thus old. It refuses to die. The hot coils are under the outside skin, no cleaning. There is no fan, no air movement between freezer and fridge. The freezer has the most coils, under its skin so only the sheet metal ices up, the fridge has a small coil section around three sides at the top for cooling with a drip tray running under it. Only thing running is the compressor, thermostat is mechanical, you can hardly hear it running, it just sits there and makes cold. I cannot see how anything of comparable size on the market today will save energy over such a simple and efficient design.
So... to run a fridge rated at 700 kWh/year (pretty average) with a peak of 1000 watts, you'd be running almost 2 hours per day, end power consumption 1.92 kWh per day? This would bring our battery requirement to 160 amp-hours at 12 volts. That'd be two of those 80 amp-hour batteries you showed me earlier... You could get four and in some way rotate them charging in the sun and discharging at the inverter... Fun!
Two hours in 24, 5 minutes every hour, sounds about right. But why not just hook the panels and inverter to all the batteries and not rotate?
I guess if your panels are big enough, there would be no need of rotation. :-)
Grey_Wolfe (author)  forgesmith8 years ago
Don't have an iPod, lol. But seriously, was just trying to learn the basics of the solar ice maker to try to work on modification from there.
Grey_Wolfe (author)  Grey_Wolfe8 years ago
Good point on the limited use factor, though. Hadn't really thought of that.
KISS, not just a rock band. You can get stuff that makes cold easy enough, just needs current. Making the current from solar is easy enough. Simple design choice.
NachoMahma8 years ago
. ArkLa Servel used to make natural gas driven air conditioners. Should be the same basic principle.
I'm pretty sure they make RV refrigerators that run on propane, same thing.
Oh yeah, propane, natural and kerosene used to power lots of fridges. They haven't been used too much in the U.S. for 40 years (excep in RV's), but were still in use in New Guniea when I was there in the 90's.
skunkbait8 years ago
Without huge solar panels it would be difficult. But, it might be easier, if you could put the "ice tray" about 40' underground. At least that way, you'd only be trying to overcome a temp of 50 degrees (farenheit) or so, compared to surface temp.
I can see that turning in to an oops I seem to have frozen the well again moment...
Hey, then I could mine the ice!
Grey_Wolfe (author) 8 years ago
Lots of great solar ideas guys, thanks. But I'm pretty sure that generally solar ice makers aren't so much about gathering solar electricity then powering a cooler. I thought it was basically a thermodynamics trick. Just don't know how to do it. Still, I'm loving all the input, please keep it coming.
Grey_Wolfe (author)  Grey_Wolfe8 years ago
I believe it uses heat transfer to create a very cold temperature. Basically, the hotter it is on one end, the colder the other. At least, that's what I was led to believe, but maybe the idea really was just gathering electric energy from solar. How big of a sterling would it take to power a house, I wonder? Using a parabolic dish would of coarse allow for a smaller motor, but still.