Heat Transfer and friction factor data at various volume concentrations for flow in absorber/Receiver and with and without twisted tape inserts is determined experimentally (with water and silver Nanofluid). The experiments are conducted in the Reynolds number range 500≤ Re<≤ 6000 with twisted tape inserts of different twist ratios in the range 0.577 ≤H/D/≤1.732. This study shows that twisted tape inserts when used shows great promise for enhancing heat transfer rate in absorber. The heat transfer coefficient and friction factor of 0≤ Φ≤0.1 % volume concentration of silver Nanofliud are higher compared to flow of water in absorber/receiver. The experiments show that Nussult Number, friction factor and enhancement efficiency are found to be 1.25-2.10 times, 1.0-1.75 times and 135%-205%, respectively, over, plain absorber/receiver of parabolic trough collector. Finally new generalized correlations function for predicting heat transfer and friction factor for turbulent flow of both water and Silver Nanofliud are proposed with tape inserts. © 2013 The Authors.