[quote=@Ophidian]
<Snipped quote by TheSovereignGrave>

You know that whole energy can't be created or destroyed rule?

Forget that rule. 
[/quote]

REEEEEEEE

Listen here you lil' shits. 'Vacuum Energy' is the concept of generating energy from the fact that the 'lower you go' (E.G. quantum particles), the more random shit happens. Basically, modern science sees that if you go low enough, you (probably) get particles that spontaneously appear in pairs and collide with eachother, exploding. If you can stop them from exploding and get the particles, that's effectively free energy. The thing is, those spontaneously appearing particles never stop spawning, as far as we know.

So if you can harness that shit from a vacuum, that's literally free energy. No ifs ands or buts, As we understand. Of course, they also thought nuclear reactions would totally destroy the earth, but y'know.

Edit: Alternatively, 'vacuum energy' has also meant 'sucking up alternate universes' and 'literally magic lol'