Solar Still
Sunlight evaporates dirty water and recondenses it clean — a survival desalination model.
Start building ↓The build
Set up
Put dirty water in the bowl with an empty cup in the centre.
Cover it
Seal the bowl with cling wrap.
Add a weight
Place a small weight over the cup to dip the wrap.
Wait in sun
Clean water drips into the cup.
Sun evaporates pure water vapour, leaving salt and dirt behind; the vapour condenses on the cool wrap and drips clean into the cup.
A closer look
Distillation separates water from dissolved solids because only the water evaporates — the same cycle that makes rain.
Variables to test
- 1 Compare salty vs muddy source water.
- 2 Cool the lid — does more water condense?
More Environmental
Layered Water Filter
Sand, gravel and charcoal layers visibly clear muddy water — a model of natural and plant filtration.
Pizza-Box Solar Oven
Foil and plastic wrap turn a pizza box into an oven that melts chocolate with only sunlight.
Wind Turbine Generator
Blades drive a small generator to light an LED, modelling clean wind power.