This paper discusses the transient performance of a tubular solar collector under different operating conditions. The different components, such as the cover, receiver envelope and receiver and fluid inside the cylindrical tube are considered as a separate node. The energy balance equations for each node are solved by using the finite difference technique. It is found that a tubular collector with a cusp reflector is better in performance than the evacuated tubular collector lone. The rise in the temperature and efficiency of the collector is a sensitive function of mass flow rate, length of the tube, gap between receiver and receiver envelope, optical and thermal properties of the cover, receiver envelope and receiver. For efficient use of solar energy, the length and gap between the receiver and receiver envelope are to be fixed at their optimum values (~ 1.0–1.5m and ~ 10 mm) and the flow rate kept as small as possible (~ 0.0001 kg/s).