A parabolic trough is a type of concentrated solar power (CSP) system. Long, curved mirrors arranged in a line concentrate sunlight on pipes located at the mirrors’ focal center. These pipes run down the length of the trough and contain an oil that is heated by the concentrated sunlight. This oil flows through the pipes to a power plant, where it boils water. The resulting steam produces electricity in a conventional steam generator. During the course of the day, a motor rotates the mirrors to track the position of the sun. To limit intermittency and improve dispatch capability, these systems may have molten salt storage or a co-firing natural gas system.