Optimization of Molten Salt Parabolic Trough Power Plants using different Salt Candidates

Abstract

Molten Salt as alternative heat transfer media for parabolic trough systems shows a potential for lowering the levelized cost of electricity (LCoE). Kearney [1] and Kolb [2] described that a reduction of LCoE greater than 10 % depending on the salt mixture is possible. Nevertheless, also some challenges are being addressed; a main concern is the necessity to provide anti-freeze protection that can be realized by equipment design, plant layout and operational decisions. A first commercial molten salt parabolic trough plant has been inaugurated 2010 in Italy – the Archimede project [3]. The chosen liquid salt and its thermodynamic parameters are similar to the Solar-Two plant [4] although Solar-Two is a solar tower system. The proposed paper will assess a variety of different molten salt parabolic trough systems using different operating temperatures, different power blocks, different salt candidates, different locations, different storage sizes and different solar field sizes in order to identify the most reasonable configurations and its thermodynamic parameters. A detailed analysis will be done on the thermal energy consumption of the solar field during night time operation in order to avoid freezing of the salt in the solar field. A comparison of the LCoE will be presented.