Innovative thermal storage strategies for Fresnel-based concentrating solar plants with East-West orientation

A novel proposal to drive forward linear Fresnel technology within the solar market competitiveness is presented in this paper. It consists of two innovative storage strategies conceived for the management of a flexible three-tank thermal storage system of molten salts, which seeks the enhancement of part-load plant efficiency in alternative East-West oriented Fresnel solar plants. A consistent methodology has been developed in order to assess quantitatively this new proposal by means of annual performance simulations of a global model. This allows the comparison of the aforementioned approach of Fresnel-based plant with reference parabolic trough collectors (PTC) and linear Fresnel collectors (LFC), which are equipped with state-of-the-art two-tank thermal storage of molten salts and North-South solar field orientation. Results show an increase of more than 10% in annual plant efficiency compared to conventional North-South Fresnel plants based in high latitude locations, i.e. Almeria (Spain). This boost in LFC performance would imply narrowing the gap with PTCs, where expensive high optical quality receivers are used. Findings in this paper state that the proposed innovative strategies are proven to be more effective when low quality receivers are used and when the solar fields are located far from tropics.