1. Introduction
Solar-thermal power plants have undergone considerable
technological and industrial development in recent years. These
power plants use the sun’s radiation to heat fluids and produce
electricity. This is done using a device that concentrates direct solar
radiation onto a receiver. Depending on the sunlight concentration
system used the main four technologies available on the market can
be classified as [1e3] a) parabolic trough collector, b) linear Fresnel
collector, c) central receiver system with dish collector, and d) solar
power tower receiver system with heliostats. A fifth system is the
solar updraft tower, also called solar chimney plants, but this
technology is under research and development and therefore it has