Improvements of the optical performance recently discussed, would lead to a better incident angle modifier and a higher optical efficiency (Improved Trough). Results of equal simulations with a flat plate collector and a vacuum tube collector with CPC (no shading or soiling assumed) permit a comparison of the trough collector’s yield . The annual energy
yield is presented in figure 13 as a function of the fluid temperature in the range of 50 to 200°C.