TERC receivers for DISS collectors

Abstract
Optimisation of parabolic troughs is a compromise between optical quality, heat losses and component costs. In this paper, we are interested in analysing the behaviour of parabolic trough collectors with a Tailored Edge Ray Concentrator receiver. These receivers have been proposed to substantially improve the long term behaviour of parabolic troughs by increasing total concentration ratio, and thus reducing heat losses, while maintaining optical parameters. The optimisation of the design, taking as the primary reflector the current LS3 collector to be implemented at the Plataforma Solar de Almería within the DISS project, led us to an optimum design defined by : Total concentration ratio : C_tot=35 ; Absorber radius : R_a=2.57cm ; TERC angles : Half acceptance angle δ=0.85° and truncation δ_t=0.69°. Applying a long term prediction model, we have quantified advantages of the proposed design : TERC benefits represent between 2 and 3% of the annual electricity delivery when using evacuated selective absorbers and, When using a low-tech absorber in the TERC receiver (non evacuated, black painted) it is possible to get similar results that with the standard LS3 receiver (evacuated and with selective coating).