**5.2. Economic benefits**

PV/T system can provide an economical solution for industrial and domestic power demands. Studies indicate a significant reduction in energy consumption produced from conventional resources due to the use of such system [23, 59]. Taylor et al. [60] also narrated that a solar thermal based power plant of 100 MW capacity can save about \$3.5 million per annum if the nanofluid receiver is incorporated with it. Nanofluids need a smaller area for heat transfer thus making the PV system compact and reducing the costs [51]. The economic analysis depicted that the cost of energy produced by nanofluid based PV/T system is 82% less than the current prices in Saudi Arabia [33]. Nanofluid system is predicted to takes only 2 years for pay-back [26]. Sardarabadi et al. [61] evaluated that size reduction by 21, 32,33 and 34 from energy viewpoint and 5,6,7 and 6 from exergy viewpoint for PVT/water, PVT/TiO2 , PVT/ZnO and PVT/Al2 O3 respectively. By size reduction we mean the amount of material saved for the same required energy and exergy outputs at the same conditions.
