Solar stills are equipment that use solar thermal energy to

Solar stills use solar thermal energy to distil water and remove impurities.

Drying grains uses solar dryers, a different application of solar heat.

Generating electricity is done by photovoltaic cells or solar thermal power plants.

Pumping water is the task of solar powered pumps, not solar stills.

In a still, sunlight evaporates water, leaving salts and contaminants behind.

The vapour then condenses on a cover and is collected as clean, distilled water.