The schematic diagram of a large scale solar thermal electric power generating power plant is shown in Figure 1. The receiver is made of a cylinder 0.7m in diameter and 13.5 m tall. At the design optimum operating temperature, the average outer surface temperature of the receiver is 675C and ambient air temperature is 30C (refer to appendix to find the values of fluid properties). Figure 1: Process flow diagram Solar thermal electric power generating power plant a) Calculate the rate of heat loss from the receiver via natural convection. (25 marks)