The molten salt linear Fresnel model simulates the performance of a linear Fresnel system that utilizes a sensible-heating liquid such as molten salt as the heat transfer fluid (HTF) in the field. This model complements the direct steam linear Fresnel model for linear Fresnel systems that utilize water/steam as the heat transfer fluid.

The molten salt linear Fresnel model includes a thermal energy storage model, which may use either the same HTF as the solar field, or a different fluid. If the field and storage system use the same HTF, the system is modeled as a direct storage system with no heat exchanger between the field and storage system. If the field and storage fluids differ, SAM includes a heat exchanger in the storage system that impacts exergetic system performance. SAM always assumes a heat exchanger between the liquid HTF and the steam flow in the power cycle.

Several options are available for modeling the performance of the solar field. Collector optical performance can be specified using incidence angle modifier equations in the transversal and longitudinal directions, or an optical efficiency table can provide the optical efficiency as a function of either solar position or collector incidence angles. The linear Fresnel model allows you to specify thermal loss relationships either using a set of polynomial equations or with a detailed evacuated tube receiver model.

The molten salt linear Fresnel model represents all major subsystems associated with indirect systems, including the solar field, optional thermal energy storage system, optional auxiliary fossil backup system, steam Rankine power cycle, heat rejection system, feedwater pumps, and plant control system. Output from the model includes financial metrics as well as detailed performance data covering temperature, pressure, mass flow, thermal energy flow, water use, parasitic consumption, turbine power output, and many other relevant values.

The molten salt linear Fresnel model can also be used for compact linear Fresnel reflector (CLFR) systems by using the appropriate coefficients with the polynomial heat loss model for the receiver geometry and heat loss parameters on the Collector and Receiver page.