How To Make a Portable Solar Water Distiller (DIY Guide)

A portable solar water distiller, also known as a portable solar still, provides clean water that can be used for a myriad of things. Learning how to make one from scratch is an essential survival skill.

Here is how to make a portable solar water distiller in a few steps:

Make a watertight topless box.
Paint the box black on the inside.
Make a gutter pipe.
Elevate the side opposite the gutter pipe.
Cover the box with glass.
Install a faucet valve.
Start using your portable solar water distiller.

In this article, I will discuss the steps to making a portable solar water distiller in detail. The process is relatively simple, and there are a variety of ways to adjust it according to your needs and what you have on hand.

1. Make a Watertight Topless Box

The first step is to make some sort of watertight container with no top. I recommend that you make the box out of sturdy material such as wood or even metal. Making the box out of wood is the easier option because woodworking tools are easier to handle and more accessible.

Some people recycle a used metal container (such as a biscuit tin) by cutting off the top side. In any case, ensure that the box is wider than it is tall. Use a food-grade silicone adhesive gel to seal the corners and edges and make the box watertight.

2. Paint the Box Black on the Inside

To heat up the water in the distiller using solar energy, paint the interior of the box entirely black. Use food-safe black paint that can withstand some heat. The black surface will absorb more heat. As such, it will get hotter and, in turn, evaporate the water faster.

3. Make a Gutter Pipe

You should install a gutter pipe on one side of the box, where clean (distilled) water should flow out; a simple PVC pipe should do the trick. Preferably install the pipe in one of the top corners of the box, and don’t forget to apply a sealant to ensure the box stays watertight. The last thing you want is a leak. Otherwise, the distillation process won’t work correctly.

4. Elevate the Side Opposite the Gutter Pipe

Depending on your preference, you may want the portable solar water distiller to lay on the ground, or you might prefer to build legs for it like a table. In any case, it shouldn’t be perfectly level—you should elevate one side of the distiller to ensure water flows towards the gutter pipe.

Make the legs on the side opposite to the gutter pipe slightly longer to elevate that side. You can also only add legs to one side in order to create the same slope. A slight slope is best since a steeper slope poses the risk of breaking the glass top you should install in the next step.

5. Cover the Box With Glass

The top of the box should be covered with some type of glass to let sunlight through and to create a surface for condensation. If you don’t have access to a sheet of high-quality glass, a windshield or car window is an easy option to use. Just ensure that you’ve cleaned and washed the glass thoroughly.

As you’ve done earlier, use a food-grade silicone sealant to ensure that the glass is firmly stuck to the wood. Once you’ve installed the glass top, you can ensure that the distiller box is watertight and vapor-tight. Try pouring a little bit of clean water into the box and watch for any leaks.

To check if the box is vapor-tight, try to blow into the gutter pipe. It should become more and more difficult to blow air into the box because there is nowhere for the vapor to escape–that is, it’s vapor-tight.

6. Install a Faucet Valve

Next, you’ll need some way to pour water into the distiller, and the best option is to install a faucet valve. It makes for easy pouring, and you can easily turn the faucet valve closed when needed. You’ll need a drill bit to make a hole in the box, and installing the faucet valve is a simple procedure.

I found this cheap but durable Eastman quarter-turn angle-stop valve (available on Amazon.com), which was perfect for the job.

7. Start Using Your Portable Solar Water Distiller

Now that you’ve done all the building and hard work, there’s nothing left to do but use your portable solar water distiller. Collect water from any source you can find—a lake, river, or even the sea. You can even set containers overnight to collect morning dew.

Once the water is inside the distiller, place a container (such as a water bottle) at the spout of the gutter you made. Make sure that your portable solar water distiller is placed somewhere that gets plants of direct sunlight to speed up the process significantly.

The sun should bring up the temperature of water in the distiller box, causing it to evaporate. Since the box is water and vapor tight, the evaporated water has nowhere to go, and it will condensate on the glass top you’ve made.

Water will flow from the glass top towards the gutter and into your bottle. The result is pure, distilled water that is safe to drink but lacks taste because it does not include any electrolytes which are normally found in drinking water.

Final Thoughts

Distillation without using a heat source to boil water is a process that takes a very long time. However, a portable solar water distiller is an easy method to get clean water without the need for using any non-renewable energy, making it super eco-friendly.

Use the distilled water in cooking, washing, or even as drinking water. It might not taste perfect, but it’s clean enough for safe consumption. You can make the distiller as big or small as you want to get more water or increase portability.