“Finally he burnt the whole fleet in an amazing way. Directing a plane and thin mirror to the sun, he concentrated the rays on its surface, the air around burnt itself and a burst of flame reached the anchored ships destroying them”. (Zonaras, Epitome 4.3).

The technology of that time probably allowed to cause serious damages but we don’t think it could create the devastation described. However, already at that time people knew the potentialities of the solar thermal energy when the sun rays are concentrated. When we were children, we all tried to burn some paper using a magnifying lens to concentrate the sun rays. In short we can say that the use of the solar thermal energy is almost intuitive and intrinsic.