how much solar energy hits the earth
12.2 trillion watt-hours converts to 12,211 gigawatt-hours, and based on 8,760 hours per year, and 197 million square miles of earthâs surface (including the oceans), the earth receives about 274 million gigawatt-years of solar energy, which translates to an astonishing 8.2 million âquadsâ of Btu energy per year.