This description is for solar powered air purification systems, which use the power of the sun to clean the air in your home or office. These systems are designed to reduce airborne pollutants such as dust, pollen, smoke, and other allergens, as well as reduce odors and VOC
From Wikipedia
A solar-powered desalination unit produces potable water from saline water through direct or indirect methods of desalination powered by sunlight. Solar energy is the most promising renewable energy source due to its ability to drive the more popular thermal desalination systems directly through solar collectors and to drive physical and chemical desalination systems indirectly through photovoltaic cells.