How to Make a Solar Still

A solar still uses sunlight to distill water.

A solar still (distillation unit) is a low-cost way to make distilled water from the tap, salt water or lake water. The sun pulls out distilled water, leaving impurities and microscopic life forms behind. It's possible to create a solar still at home using Plexiglas panels.

Things You'll Need

• 24-by-48-inch Plexiglas panel
• 24-by-24-inch Plexiglas panel
• Utility knife
• Epoxy
• Isopropyl (rubbing) alcohol or other disinfectant
• Towels
• Black pan
• Silver or white pan

Instructions

1. Use a utility knife to carefully cut the square, 24-by-24-inch Plexiglas panel diagonally across. This will leave you with two triangular panels of equal size.

2. Use epoxy to glue the two rectangular panels together along the 48-inch side at a 90-degree angle. Glue the triangular pieces to each end of the 90-degree panels, to block the ends and give the structure stability. Allow the epoxy to dry.

3. Reinforce the Plexiglas structure with epoxy, sealing all seams sufficiently and reinforcing the corner connections for greater strength. Allow the epoxy to dry.

4. Wipe down the interior of the Plexiglas housing with disinfectant and towels. Wipe down the inside of a large silver or white pan (no smaller than 50 by 36 by 6 inches). Wipe down the inside of a small black pan (no larger than 12 by 36 by 6 inches). Allow all surfaces to dry.

5. Place the larger pan in a stable location, preferably fully exposed to the sun, with the long sides facing east and west.

6. Put your source water in the black pan and center the pan in the larger pan.

7. Place the Plexiglas housing inside the large pan, covering the smaller pan completely without touching it. The Plexiglas housing will allow sunlight to heat the source water and trap the evaporated water inside. Water vapor will collect on the Plexiglas walls and the distilled water beads will run down the walls to collect inside the outer pan.

Tips & Warnings

• Use bricks or heavy books to hold the Plexiglas panels steady while the epoxy dries.

• Carefully remove the housing and source water pan when collecting your solar-distilled water. Splashing salt or brackish water from the source pan into the distilled water will contaminate it; do not drink contaminated water.

• Scale the dimensions of the housing and pans up or down to suit your location and water requirements.