A solar blanket is a plastic blanket that floats on the pool surface. The sun light is magnified through the plastic and heats the pool or spa water.

A solar blanket is a popular application for solar energy.

a translucent floatable blanket that is placed directly on the pool's surface. Warms the water by reducing evaporation (a cooling process) and utilizing the Sun's rays passing through the blanket. Usually made from an air bubble filled plastic sheet.