Hurricane Hurricanes are a huge heat engine. They suck heat from the humid air over a warm tropical ocean and then release energy through the condensation of water droplets. It turns out that the vast majority of the heat released in the condensation process is used to hold up a huge amount of water in the thunderstorms and only a small portion drives the storm's strong horizontal winds. If you're mathematically inclined: An average hurricane produces 1.5 cm/day (0.6 inches/day) of rain inside a circle of radius 665 km (360 nm)--lots more near the eye, less at the edge. Converting this to a volume of rain gives 2.1 x 10^16 cm^3/day. A cubic cm of rain weighs 1 gm. The latent heat of condensation produces 5.2 x 10^19 Joules/day or 6.0 x 10^14 Watts. This energy released in the condensation process is equivalent to 200 times the world-wide electrical generating capacity! For a mature hurricane, the amount of kinetic energy generated is equal to that being dissipated due to friction. The dissipation rate per unit area is air density times the drag coefficient times the windspeed cubed--but I'm sure you already knew that. Assuming an average windspeed for the inner core of the hurricane of 40 m/s (90 mph) winds with a radius 60 km (40 nm), one gets a wind dissipation rate (wind generation rate) of 1.5 x 10^12 Watts. This energy that is converted into wind is equivalent to about half the world-wide electrical generating capacity - still an amazing amount of energy!