Question

Answer all three parts

The sun transfers energy to the earth by radiation at a rate of approximately 1.00 kW per square meter of surface. Part A If this energy could be collected and converted to electrical energy with 26 % efficiency how large an area (in square kilometers) would be required to collect the electrical energy used by the United States? (1.0×1019 joules per year).

Answer 1

Please find the attached image

Energy emitted by sum/m^2/sec = 10^3 electrical energy obtained from this energy = 26/100 (10^3) = 260 J Electrical energy obtained in one 1 year from 1 m^2 = (260) (365) (24) (3600) let Area required be A m^2 than (260) (365) (24) (3600)A = 1.0 times 10^19 A = 12.2 times 10^8 m^2 A = 12 times 10^2 Km^2 A = 1200 Km^2 let length of solar cell = l km l^2 = A l^2 = 1200 l = 35 km or 22 miles