A solar water distiller is a simple device that uses solar radiation to purify or distill contaminated water [16]. It mimics nature's water cycle process of evaporation and condensation to produce clean, potable water from impure sources like saltwater, brackish water, or contaminated freshwater.
How Does a Solar Water Distiller Work?
The fundamental principle behind a solar water distiller is the harnessing of the sun's energy. Here's a simplified breakdown:
- Collection Basin: Contaminated water is placed in a basin, typically dark-colored to absorb more solar radiation.
- Evaporation: Sunlight passes through a transparent cover (usually glass or plastic) and heats the water in the basin. The water evaporates, leaving behind impurities such as salts, heavy metals, and pathogens.
- Condensation: As the water vapor rises, it comes into contact with the cooler inner surface of the transparent cover. The vapor cools down and condenses back into liquid water.
- Collection Channel: The condensed, pure water trickles down the angled cover into a separate collection channel or container.
Essentially, the process separates pure H₂O molecules from contaminants, providing a sustainable method for water purification, especially in areas with abundant sunlight but limited access to clean water sources.
Components of a Basic Solar Still
A typical solar water distiller, often called a solar still, includes several key components:
- Sealed Box or Frame: Provides structure and insulation.
- Black Absorption Surface: The bottom of the basin where contaminated water sits, designed to maximize heat absorption.
- Transparent Cover: Usually glass or UV-resistant plastic, angled to allow condensation to flow down.
- Collection Trough: Gathers the distilled water.
- Water Inlet/Outlet: Allows for adding contaminated water and removing the purified water.
| Component | Function |
|---|---|
| Solar Radiation | Provides energy for evaporation |
| Contaminated Water | Input source containing impurities |
| Absorption Surface | Heats water using solar energy |
| Transparent Cover | Allows sun in, cools vapor for condensation |
| Collection Channel | Gathers the purified water |
| Purified Water | Output – clean, distilled water |
Applications and Benefits
Solar water distillers offer a practical solution in various scenarios:
- Providing safe drinking water in remote or off-grid locations.
- Emergency preparedness for water purification.
- Supplementing water needs in coastal areas using saltwater.
- An environmentally friendly method powered solely by solar energy.
While relatively slow in production compared to conventional methods, their simplicity, low operating cost, and reliance on a free, renewable energy source make them a valuable technology for water purification.
