A couple of years ago, I wrote an incredibly nerdy post about videogame consoles and energy. (I'm still stupidly proud of that lame Castlevania reference in the first line. Seriously.)

Why, you might ask, am I bringing up my nerdiness again? Well, it's because I ran into this article on Ars Technica on energy and videogame consoles that cites a Carnegie Mellon study with surprising results: America used nearly 16 terawatt-hours of energy on videogames in 2010, and a good chunk of it was wasted.

In fact, the study assumed that 30% of all gamers left their consoles on 24/7.

That's just an estimate, of course. But when I wrote my post in 2010, I didn't even consider that angle. How wrong I was!

So if you are one of the approximately 30% of gamers who never turn their consoles off, you now have an easy way to save some money. According to the article, idling at your console's main menu uses nearly as much energy as playing a game.

For me, leaving the system on all the time doesn't seem worth it. The Xbox 360 starts up in less than a minute. I don't have a PS3, but I bet it's about the same.

And once your machines are off, you can start worrying about the energy they draw when they're not even on at all! But first thing's first, right?

Elizabeth Spencer is a communicator at DOE's National Renewable Energy Laboratory, which assists EERE in providing technical content for many of its websites.