A fuel cell, located 15 miles outside a town, supplies the town's three-phase distribution network. The fuel cell voltage is maintained at 12.47 {kV}. The local network voltage is also kept at this level. Calculate the required phase angle difference between the fuel cell and local network voltage if the fuel cell supplies 15 {MW} to the network. The line impedance is 0.23+j 0.45 Omega / mile.