
A parabolic trough collector (PTC) is a type of that is straight in one dimension and curved as a in the other two, lined with a polished metal . The which enters the mirror parallel to its plane of symmetry is focused along the , where objects are positioned that are intended to be heated. In a , for example, food is placed at the foc.

In 1897, , a U.S. inventor, engineer and solar energy pioneer built a small demonstration solar engine that worked by reflecting solar energy onto square boxes filled with ether, which has a lower boiling point than water, and were fitted internally with black pipes which in turn powered a steam engine. In 1908 Shuman formed the Sun Power Company with the intent of building larg.