According to the second law of thermodynamics, the amount of disorder or entropy in the universe can only ever increase. There are pockets of order that resist temporarily by exporting their entropy, typically by giving off heat. Living systems are an example: they maintain internal organization by dissipating energy into their surroundings. While listening to Brendan Graham Dempsey interview Jim Rutt, I learned that the human body, per unit weight, gives off more energy than the sun.
The basal metabolic rate of a human body is 100 W. Assuming an average weight of 60 kg, that’s 1.7 W per kg. The sun produces 0.00019 W per kg (source). Hence, the human body produces almost 10,000 times as much energy per unit mass.
Note that the sun’s mass is an incomprehensible 2 × 1030 kg, so overall it still produces a lot more (1014 to 1015-fold more) energy than all humans combined.
The 100 W humans put out really isn’t that much and is comparable to a large LED TV or a coffee maker.
Read more about Fermi calculations here.
Nehaveigur 