This paper evaluates the performance of standalone thermal system and cogeneration PVT system under concentrated two stage linear Fresnel lens (FL) based system with convex lens as Secondary Optic Element (SOE). Experiment for standalone thermal system with two stage concentrator investigates the thermal efficiency of the system with copper plates as thermal collector. The experiments to obtain VI characteristics of PV module were done without lens, then with FL and with both FL/CL. The electrical efficiencies were 12.23%, 11.5% and 9.2% respectively which shows fall in efficiency as a result of concentration. Peak powers were 3.42 W, 3.74 W and 4.23 W respectively which shows there is rise in output power. Increase in output power from no lens to single lens was 9.3% and increase in output power from single lens to two stage lenses was 13.1%. The position of Primary Optic Element (POE) was determined by adjusting distance from 10 cm to 35 cm. At 30 cm max power was obtained so POE was kept at 30 cm. In similar manner, SOE was positioned at 15 cm from POE. The net efficiency of standalone thermal system and PVT system with two stage concentrations was 47.61% and 53.7%. (C) 2020 Elsevier Ltd. All rights reserved.