A typical solar farm harvests solar energy at a rate of 100

A typical solar farm harvests solar energy at a rate of 100 watts per square meter (this includes efficiency) for installed PV panels. Approximately how many square kilometers of installed PV panels is needed to generate 1TW of power?

Solution

k(x^2) = 100 watts = 10^2 watts <-- this requires 1 sq m

1TW is 10^3*10^3*10^3*10 watts = 10^10 watts = (10^5)^2

So, 10^10 would require 10^10 / 10^2 = 10^8 sqaure km would be required