Concentrated solar power (CSP) is a typical renewable energy source which grows fast in areas with high solar irradiance such as Spain, India, South Africa, China, Chile, Australia, Middle East, Morocco, and the United States. The CSP plant generally consists of heliostats, solar receiver, hot & cold salt tank, steam turbine/ generator, piping & tubing systems, and air-cooled condenser.

In a CSP system, the sunlight is reflected from a large series of widely deployed heliostats/ reflectors thay focus energy to the receiver located at the top of a central solar tower. The solar tower is one concentration technique that has been developed. The design utilizes molten nitrate salt as a heat transfer fluid. The solar receiver first converts the absorbed energy into thermal energy by heating molten salt, which is stored in the hot molten salt storage tank. Steam can then be produced on demand by pumping the hot molten salt through a steam generator. Cold molten salts are returned to a cold molten salt tank, from which they are sent to the solar receiver to be heated again.

The solar receiver power is working as a heat exchanger in essence. Inconel alloy 625 tubes (UNS N06625) are generally chosen to handle the high-temperature molten-salt fluid. This is because nickel alloy 625 not only has high oxidation/ corrosion resistance but also exhibits outstanding creep resistance at elevated temperatures as well as enhanced low-cycle fatigue properties.