Ultimate Guide To Solar Water Distillers: How To Make A Solar Still 101

Do you want to learn more about solar water distillation?

Are you wondering about how solar still installations can help you make clean water on demand?

Are you looking for easy, quick tutorials that will help you create your very own solar still?

If you are wondering about the answers to any of these questions and more, you are definitely in the right place! 

Solar distillation is a great way to produce pure, potable drinking water that is safe for consumption by you and your family with nothing but a little ingenuity and the power of the sun! If you want to learn more about how this all works, read on below...

How to make a DIY solar water distiller

If you want to make a solar still, here are the things you need, according to the International Journal of Advanced Science and Technology:

Still Basin

This is the biggest part of the solar still system. This is where the water you’re going to distill is poured. Look for material that absorbs heat, meaning it stays hot and doesn’t conduct heat very well. You can use a leather sheet, silicon, a mild steel plate, reinforced plastic or galvanized iron.

Side Walls

This is what gives the solar still structure. The material you use should also be able to resist heat transfer to the surrounding area of the still. Essentially, the more heat trapped, the more efficient your solar water distillation system is. More heat equals more solar still goodness!

Aside from that, your solar still side walls should be able to support the cover and resist the water from spilling. You can use wood, concrete, or reinforced plastic. You can combine materials, with one side wood and the other side plastic for optimum heat resistance.

Consider something at least 15mm thick for your solar still walls and you should be good to go.

Top Cover

This is the surface that’s supposed to collect the condensed vapour from the distillation process and the only way for heat to get into the solar still.

Your solar still cover should be transparent, resistant to water absorption and can be easily cleaned and very smooth.

Typical materials for this part are glass or polythene that’s 3mm thick. It has to be slightly longer than your solar still basin since you’re going to install it an angle so the distillate drips into a receptacle.

Channel

This is where the distilled water is collected into a trough or passage which then trickles out onto a channel. Typically, it’s a small inlet or tube that lets the water drip into a pail, mug or pitcher.

You can use PVC or plastic for this part of your solar still.

You can also put a support system for your top cover (as glass can be quite heavy) and additional duct tape to seal all the corners and sides of the still, to make the solar water distillation system more efficient.

Other variations of the system use multiple trays of water under one large cover to maximize the efficiency of the solar still.

Here are some other types of stills:

● Multi-effect

● Basin

● Double Slope

● Wick

● Multi-wick

● Diffusion

● Greenhouse

Instead of making one large surface for your solar still, separating the water into smaller trays helps the liquid evaporate faster. A larger body of water would need a higher temperature to vapourize.

Here’s a setup for a more solar water distiller plans, if you’re willing to create a larger solar still system, especially if you want to have more than a few litres of distilled water in a day: http://pdf.usaid.gov/pdf_docs/PNABC961.pdf

The instructions above are specifically for a single-effect solar still.

How do you use a homemade solar water distiller?

So you’ve set up your solar still system in a good part of your property and you’re ready to purify some water!

Here’s how you collect distillate from impure water fed into your solar still:

Depending on how wide your surface is and how hot it gets in your area, the optimum amount of water you can put in varies. It’s best to start with a thin surface and try to add more to see how efficient your system is.

If you want to use more scientific methods, refer to  this design: https://www.teachengineering.org/collection/cub_/lessons/cub_waterqtnew/cub_waterqtnew_lesson01_factsheet_solardistillation_v2_tedl.pdf

Essentially, though, a still that has 10 square feet of condensation surface can produce around 2 litres of water.

What can you use the water for?

So you’ve collected your water from your DIY solar water distiller. What can you use this for?

Drinking

As long as you used softened or salt water, the liquid is safe to drink. Black or brackish water may need to be treated first before being put in the solar still or treated twice in the system.

Washing clothes and utensils

In areas where clean water is hard to come by, being able to produce distilled water can improve the health of the community greatly. Washing with clean water prevents microbes and undesirable substances from clinging to eating utensils and clothes.

Bathing

For sick people, bathing in distilled water may be their only option for protecting their skin and preventing further infection.

Cooking

Using clean water improves the taste of food and makes the food free of contaminants.

Emergencies

During water shortages and natural disasters where tap water is unavailable, being able to use a solar still in an emergency cans save lives.

Things to remember about using solar water distillers for home

Solar stills have so many uses, but making the most of them isn’t that easy.

Not that efficient

As you may have noticed, this system is not that efficient if you have to provide drinking water beyond yourself. And even at 2 litres of water collected per solar still per day, it still doesn’t meet people’s usual water requirement, especially if you live in a tropical country.

You can make more, but it also costs more

Expanding your solar still can yield more water—but of course, would need more work.

Softened and tap water are the best starting liquids

Since you use the gentlest of methods to heat your water, you have to help the process along. Black, brackish water may need to be distilled twice. Using softened water or at the very least salt water can lighten the burden on the system.

Monitor your stills

Leaving your solar still alone can also mean that the water in your receptacle or trough can evaporate again. While this isn’t a bad thing, you’re essentially wasting energy. Part of the success of the system is knowing how much water is best for the temperatures in your area and when you have to collect and replace the water.

You can fill the still again in the evening if it’s still hot

Depending on how good your system is at resisting and trapping heat, you can use the solar still again (without cleaning) in the evening and collect water in the morning.

So now you know that distilling water without fancy machines or high-cost materials is possible. Could there be any downsides to this method? Why isn’t everyone with a large yard and tap water doing this?

PROS and CONS of solar water distillers for home use

Just like any water purification system, solar stills come with its own pros and cons. Let’s take a look:

Pros

Use any softened water

The water you use for the system can be taken from the tap, the ocean, or even a nearby body of fresh water.

Easy to maintain

Since there are no moving parts, you can be sure that your materials don’t experience wear and tear. Cleaning the solar still is easy especially if you used materials that really don’t absorb liquid that much.

Can be used with salt water

In extreme emergency situations, people lost at sea may be able to construct solar stills to increase their survivability.

No energy costs

You literally leave it out in the sun. You don’t have to use fuel or even mechanical energy (your arm or leg power) to generate heat.

No water transportation costs

Unless you want to pay yourself for fetching water from the lake, river, stream, your tap or your rainwater collection system, you don’t have to pay for transporting water at all.

Cons

Other systems are more efficient

Commercially-bought stills are more reliable than solar systems. If you’re planning on providing drinking water to more than yourself, commercial systems have more output.

Without a doubt or a spout

No matter the cost, though, the fact that operating solar water distillers for home requires no additional costs beyond materials and construction makes it a good system. You eventually recoup your losses from the materials since you don’t spend anything beyond that.

So if you’re planning to try this system out, make sure that you’ve scouted your local hardware store for all the materials first and have worked out the best spot on your property to use the system.

Don’t forget to monitor the solar still to see the best amount of water you can purify in a day and clean out your troughs and basins regularly to decrease buildup of brine.

Once you’ve got your system up and running, why not drop us a comment and tell us about your experience?

Additional Research:
http://www.sersc.org/journals/IJAST/vol29/7.pdf
http://pdf.usaid.gov/pdf_docs/PNABC961.pdf
https://www.teachengineering.org/collection/cub_/lessons/cub_waterqtnew/cub_waterqtnew_lesson01_factsheet_solardistillation_v2_tedl.pdf