Water Purifying Solar Distillery




Introduction: Water Purifying Solar Distillery

About: We designed this solar still!!!

Are you in need of some clean water but don't have the resources for filters and other fancy water purifiers? This is a tutorial that will take you step by step with easy to follow instructions on how to build your very own solar distillery made from easy to find materials. It's capable of producing over a gallon of clean water a day!

Step 1: Supplies Needed

  • Solar Collector Box
    • sheets of 22 in. by 44.5 in. by 1/8 in. thick glass - x2
    • sheet of 4 ft. by 8 ft. by 2 in. thick foam insulation with the aluminum wrapped side - x1
    • sheet of 4 ft. by 8 ft. by 1/4 in. thick plywood - x1
    • 10 ft. of 1 inch PVC pipe
    • 1 inch PVC pipe elbow - x2
    • Some scrap wood for small blocks
    • Duct tape
    • Kitchen and bath silicone
  • Dirty Water Tank
    • 5 Gallon bucket with lid
    • 1/2" threaded ball valve
    • Plastic bucket sealed tap with 1/2" threads

Step 2: Making the Wood Base

Using the dimensions in the picture, cut off an end of the 1/4 inch plywood. Make sure that your measurements are square!


Step 3: The Short Wood Sides

Using the dimensions in the picture, cut 2 pieces out of the 1/4 inch plywood.


Step 4: Wooden Entrance Panel

Using the dimensions in the picture, cut out the shape from the 1/4 inch plywood. The hole in the picture has to be at least 1.32 inches in diameter or bigger.


Step 5: Wooden Exit Panel

Using the dimensions in the picture, cut out the shape from the 1/4 inch plywood. The holes in the picture has to be at least 1.32 inches in diameter or bigger.


Step 6: Wooden Blocks

Using the dimensions in the picture, cut 8 of these blocks from any scrap wood.


Step 7: Assembling the Wood Box

Nail or staple the wood blocks onto the wooden base in the pattern seen in the pictures making sure that the blocks in the middle are centered.


Once the blocks are secure, secure the walls to the blocks as seen in the third picture. The short sides should overlap the larger sides with holes.

Step 8: Foam Base

Using the dimensions in the picture, cut the shape out of the 2 inch thick foam. This can be done with a small hack saw, a sharp razor blade, or a styro-foam specific cutting knife. Be sure to note the notches on each corner and in the mid section of each side. This is where the wooden blocks will be once the foam is inserted into the box.


Step 9: Foam Short Sides

Using the dimensions in the picture, cut 2 pieces of foam each 43.5 inches long with the cross-section shown in the picture. Make sure that the shiny aluminum side is on the tall side of the foam pieces.


Step 10: Foam Entrance

Using the dimensions in the picture, cut the shape shown. The top portion of the picture is just zoomed into the right side of the big picture. The hole in the picture has to be at least 1.32 inches in diameter or bigger.


Step 11: Foam Exit

Using the dimensions in the picture, cut the shape shown. The top portion of the picture is just zoomed into the right side of the big picture. The holes in the picture has to be at least 1.32 inches in diameter or bigger.


Step 12: Putting in the Foam

  1. Start by laying down the foam base into the wood box using some caulk as adhesive and making sure that the shiny aluminum side of the foam is facing up. Then insert the other sides with adhesive and also making sure that their shiny aluminum side is pointing inward.
  2. Use caulk to seal all of the inside corners of the still to prevent any water from leaking when it is being used.
  3. When all of the foam is in its place, there should be a slight height difference between the foam edges of the triangle portions of the wall and their respective wood portions.

Step 13: Painting

Flat black paint should only be applied to the top shiny aluminum surface of the foam base. This will absorb most of the sunlight hitting it which will heat the water faster than without.

MAKE SURE NOT TO USE SPRAY PAINT!!! Spray paint can cause the styro-foam to start melting due to a chemical reaction between the spray and the foam.

Instead, use some sort of latex based paint and brush it on thick over the entire surface.

Step 14: Building the Gutters

Using the dimensions in the picture, create 2 of these gutters using the 1 inch PVC pipe.


Step 15: Attaching the Gutters

The gutters can be pushed through the exit holes to the other side of the still. Make sure that the gutters slope towards the exit holes in in the foam and wood. This is what will collect the water to exit the solar still. They can be attached to the side using caulk while being held with clamps as shown in the picture.

Step 16: PVC Entrance Piping

With the rest of the 1 inch PVC pipe, cut one segment at 2 inches and the other close to 12 inches long. Push both of these into the 1 inch PVC elbow and insert into the entrance hole of the solar still so that the short segment points down.

The tip of the short pipe should be around 1/4 inch above the foam.

Step 17: Glass

For the glass, you can cut it yourself with a glass cutter or you can higher a professional at your local glass pane shop to cut 2 glass panes at the dimensions in the picture using 1/8 inch glass.


Step 18: Inlet and Exit Attachments

For getting water into the still, it is recommended that more pictures be taken and some better explanations so that random people can understand how to build one of these because the average person may not know what a 1/4 inch barbed inlet is.


Step 19: Optional Support for the Glass

With our extra scraps of PVC, we created a top support for our glass panes as seen in the pictures. This is not necessary, but feel free to expand upon the design to whatever fits your needs.


Step 20: Using the Still

  1. VERY CAREFULLY, place the glass in its proper spot on the solar still and tape all of the edges. For this, you can use duck tape. We recommend black and yellow caution duck tape for best looks!
  2. Connect the inlet bucket and the collection bucket to the solar still.
  3. Fill the bucket with water and open the valve.

Note: For best results, make sure the still has full view of the sun for many hours and position the entrance or exit sides towards the sun.


Step 21: Maintenance

  1. When not using the still, it is recommended to remove the glass panes and store them in a place where they are not in danger of breaking.
  2. After each use, be sure to clean the gutters and base of the still.
  3. If there are any signs of leaks, add more caulk on the inner corners of the still to prevent any further leaks.
  4. Before storing away, make sure the still is dry to prevent the growth of mildew or mold.



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    16 Discussions


    "Kitchen and bath silicone" contain anti-mold agent which are *toxic*. It is NOT recommended for food related project.

    Simply look for "fish tank silicon" in a pet shop. It may be more expensive and come in smaller tube, but it is non toxic.

    alternatively, you could use a food container cut in half to contain the water to purify, freeing you of the joint issue, as well as simplifying the cleaning process.

    ps: thanks for posting plan with a proper scale.

    Would you need a bead of silicone on the underside of the glass just above each gutter to act as a drip edge so that the water does not continue down the glass and leak down behind the foam?

    2 more answers

    The glass buts up against the foam so that the foam sides keep the glass from sliding off. We designed it like this to prevent exactly what you are talking about. Once the water dripping down reaches the edge of the glass, it hits the foam wall and drips down the wall into the gutter. If it helps, I could probably include a few more picture showing this part of the distillery.

    That’s an idea that we had as well, it was difficult to find something that would conform to the glass and create a seal while keeping the glass removable for maintenance. We found that simply sealing all the edges with the duct tape shown in the picture kept most of the water in the system. We also put a layer of aluminum foil on top of the foam so any water that collected wouldn’t get into the foam.

    Excellent detail with instructions. Did you mount the inlet bucket or is it attachable? How much water do you place in the collection basin to get best results? Did you consider placing black polyurethane sheeting on the bottom of the basin as opposed to painting it? Thanks for response.

    1 reply

    We used a flexible pipe/hose to connect the inlet bucket to the distillery. The idea was to make it easily detachable so it could be refilled. We found that having a thin covering worked the best. It allows the heat stored in the base to be more uniformly transferred to the water. We hadn’t considered anything other than paint just because it was easy.


    4 months ago

    If you scaled up the dimensions of the still would it function roughly the same?

    1 reply

    It should still work but with a greater throughput. We found through testing that having a larger surface area of the glass was key to more throughout.

    I would suggest scrounging a patio door glass insert. You can often get them for free from companies that replace ones wehre the seal has broken and the glass is dirty between the panes. The two panes can be separated with a putty knife and some patience. Clean up the edges, and you now have two pieces of safety glass.

    The slope on the glass may not be steep enough to reliably get water to run to the collectors. In addition, to maximize solar gain you want the angle to be roughly your latitude. So at 40 degrees latitude, you want an angle of 40 degrees from the horizontal.

    This makes the north side in-effective. So redesign so that it's a wedge shape instead of a roof shape. The really steep north face then is in the shade, and so is much cooler than the collector side. This may improve it's overall efficiency. The north side doesn't need to be made of glass.

    An open collecting bucket will collect flies, birds, bees. Use a closed bucket, and run the collection tube through a hole in it. A vent hole filled with a chunk of sponge will prevent it from vapour locking.


    If used steadily salts will accumulate in the water, as pure water leaves. This lowers the efficiency. You need a mechanism to drain the existing water without disturbing the glass. Depending on how warm it gets you may have issues with algae.

    2 replies

    The bucket shown in the picture is actually part of a self feeding system. We’ve left the outlet open solely for the purpose of collecting incremental data as we conducted our tests. We also conducted tests on the angle of the glass and found our design preferable to one with a higher degree of tilt. Additionally, we conducted tests with both one single pane and the dual pane design and concluded that the dual pane design was more efficient.

    We’ve provided all of our designs and findings here so you can recreate our project or redesign it yourself. Thanks for your interest.

    Slope of roof is then like a solar greenhouse. I have a great southern exposure on my south deck. I like the idea of safety glass since i am in the woods and have curious racoons who visit me every day.


    3 months ago

    Nice 'ible! This will come in handy after the "Big One" here in Commiefornia. Or after the Zombie Apocalypse. Are the dimensions metric or standard? (Kidding).

    Excellent Instructable and very well thought out design. I've made several "hasty" solar water stills, mostly with clear plastic for camping purposes. I really do like this design because it is easy to build, easy to clean (and you will need to clean it!) and it appears to me to be efficient in producing distilled water. I'm inspired to build one again on this design. Thanks for sharing it. JB

    Good survival tool. Water is your most essential need and this system will simply and reliably get it for you.

    1 reply

    If doing it as a survival tool, using white plastic allows you to set up much larger ones with less effort.


    Question 4 months ago

    What was the material cost?