Parabolic trough reflectors can be used for solar thermal electricity production. Consider a 1.1 m long parabolic trough with a reflector area of 2.2 m2 that is located in an area with high insolation of 260 W/m2 . The parabolic trough focuses solar radiation on a 3.3 cm diameter tube filled with oil as the working fluid. How long does it take until the oil is heated from ambient temperature of 26C to the desired temperature of 90C? Accordingly, what is the optimal flow rate of oil through the parabolic trough in meters per minute? Use 900 kg/m3 for the density of oil and 1758 J/(kgK) for the specific heat of oil.