A solar thermal panel (also called solar collector) is a system used to convert solar radiation into heat energy. Its origin can be traced back to the Roman Empire who already knew a way to exploit solar radiation through the greenhouse effect created by the windows of the houses. Then in the sixteenth century Leonardo Da Vinci extended a study on dish in order to concentrate the solar energy; in the eighteenth century, Lavoisier was able to melt platinum by the concentration of sunbeams. In 1767 Horace Bénédict de Saussure invented a first model of solar panel: a pot of wood lined with black cork. In 1830, John Herschel, in England perfected the system conceived by Saussure an gave rise to a cooking technique called solar cooking. Clarence Kemp, in 1891, patented the first solar thermal panel to produce hot water.