At Suva (phi=-18o) at 9a.m. on May 20, the irradiance measured on a horizontal plane was Gh = 1.0MJh-1m-2.

a. Determine the angle Theta _z between the beam radiation and the vertical, and hence find the irradiance G* = (Gb + Gd)* measured in the beam direction. (Assume that Gd << Gb as may be the case on a clear day.)

b. Under the same assumptions as in (a) determine the angle Theta _c between the beam and a collector of slope 30o facing due North. Hence find the irradiance Gc on the collector.