Flat-Plate Solar Collectors are one of the most common solar thermal technologies, designed to capture sunlight and convert it into heat for water or space heating. They consist of a flat, insulated box with a transparent cover and a dark-colored absorber plate that absorbs solar radiation. Fluid (water or antifreeze solution) flows through tubes attached to the absorber, carrying the captured heat to a storage system. These collectors are durable, relatively inexpensive, and efficient in areas with moderate to high solar radiation. Widely used in residential, commercial, and industrial applications, flat-plate solar collectors provide reliable year-round performance, especially in climates without extreme cold.