Not your fault, but the title would be misleading to someone not familiar with the subject. Energy isn't really produced - it's simply transferred and, in that process, we get usable energy with which we can do work. Energy is like matter in that it's neither created nor destroyed. It's not a trivial thing - but it's relatively unimportant. There's actually a number of different formulas for calculating energy. Everyone's familiar with E=MC^2. So, if it's got mass and speed (which pretty much everything seems to have) then it has energy. The universe is a bit like a chicken. A chicken is born with all the eggs it's gonna hatch. The universe was hatched with all the energy it's going to ever have. That energy is always in motion. Right now, you're emitting particles. Pew, pew, pew! You're actually right stuffed with energy. This is also horribly misleading: You emit, per m^3, more heat energy than the our star. But, I digress. By the way, this post is fueled by vodka.