You are discussing solar PV installation options with a homeowner who is considering a grid-tied system for their suburban home, and an off-grid system for their vacation home. Thinking about the PV system components you outlined for a grid-tied system in the project quiz, describe how the components differ for an off-grid installation. What components from the grid-tied system would not be needed in an off-grid situation? What other components would be added on?

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.