To calculate the solar energy incident on Earth, one must consider the power output of the Sun, which is 4 x 10^26 watts, and the distance from the Earth to the Sun, approximately 1.5 x 10^11 meters. The energy spreads over the surface area of a sphere with radius equal to the distance from the Sun. By calculating the surface area of this sphere, one can determine the power per square meter received at Earth's distance. Understanding this relationship allows for the derivation of an expression governing the rate of solar energy incident upon Earth. This approach provides a foundational method for analyzing solar energy impact.