Comprehensive analysis of the variables influencing the techno-economic optimization of medium temperature linear Fresnel collectors

Abstract

A Linear Fresnel Collector (LFC) is a solar concentrating technology with high potential for improvements and therefore significant cost reduction. However, LFC optimization studies found in literature show little agreement regarding optimal geometry. In this article, a study is presented to evaluate the trends of the main geometrical parameters in an optimization process of medium temperature linear Fresnel collectors (LFCs) with trapezoidal receiver. For this, a comprehensive LFC design model was developed. It includes an optical, a thermal, an annual integration of the collected energy and an economic sub-models coded in a hard-link way. This model was used to investigate the influence of the main LFC geometrical parameters and inputs on the levelized cost of heat (LCOH) produced. The geometrical parameters investigated were the number of mirrors, the width of mirrors, the gap between mirrors, the trapezoidal angle and the trapezoidal height of the receiver, while the inputs investigated were the location (Quito-Ecuador and Targassone-France), DNI data (TMY data and clear sky model) and the time frame of simulation (representative days or the whole year). Results show that the optimal LFC geometry depends mainly on the azimuthal movement of the Sun. Consequently, the trends of the energetic behavior of an LFC, when the geometrical parameters vary, are similar without regard of the latitude, DNI data or the time frame used for simulations. Reductions until 20% on the LCOH may be achieved by optimizing the geometry of such LFC.