If there's anything we humans are exceptionally great at, it's making garbage. No, we're not talking about Keanu Reeves movies again. We're talking about the stuff that's filling up your trashcan. In general, we're a wasteful society, and we don't think twice about throwing things away when we're done with them.
But what if trash could be used as a fuel source? Actually, some scientists say it can. Landfill gas, also called biogas and biomethane, is one of the few ideas on this list that's getting pretty close to being "out of the lab." While it's a relatively new technology, it's becoming increasingly popular in the U.S. and other countries because it's renewable -- and because there's no shortage of garbage on our planet.
As trash sits in landfills, the organic materials break down over time, creating methane and other gases. The landfills are covered up, and those gases are compressed to be used as a fuel source. Several corporations have begun to look for ways to use biogas to power their operations. Most recently, Apple has said biogas will help power a fuel cell farm at one of their centers in North Carolina [source: Gigaom]. It's about time we found something useful to do with all of our trash.