7. Current issues in CSP

One critical issue in TES for high-temperature applications is corrosion of the TES materials with its containment. Most of the molten salts used for TES are highly corrosive. The reactions of salts and formation of corrosion is not completely understood, and the problem still needs attention especially in the context of stress corrosion cracking in molten salts [29]. The corrosion is either in the form of oxide layer formation on the container or degradation of the container material. Standard structural materials (stainless steel or carbon) degrade after coming into interaction with salt chlorides by the chloridation. Protective coatings are under investigations to mitigate the effects of corrosion [29].

Currently, energy production from CSP technology is costly [30]. To circumvent the issue of high cost, the US Department of Energy launched the SunShot Initiative in 2011 and has put forth an aggressive research and development (R&D) plan to make CSP technologies cost competitive with other energy generation sources on the grid by the end of the decade [31]. The goal of the SunShot Initiative includes the levelized electricity cost (LEC) from solar power plants less than 6 ¢/kWh without subsidies, a round-trip annualized exergetic efficiency greater than 95%, storage cost less than \$15/kW ht, by 2020, which would pave way for rapid, and large-scale adoption of solar electricity [31].
