Greentech Media

This is our long shot, and it's one that doesn't come wrapped in a nice package of available data and detail. But Bloom is hot. Its ambitions and potential payday exceed those of possibly every company on this list. And it does have more than just buzz. It has an enviable list of VCs behind it, more than $100 million and a credible scientist at its helm (disclosure: Greentech Media and Bloom Energy share a common investor in Northport Private Equity).

The technology behind Bloom is a solid oxide regenerative fuel cell for the distributed co-generation of electricity and hydrogen in businesses and potentially in homes. The fuel cell can use any one of many different hydrocarbons as an energy source, converting them to electricity without actual combustion, cutting greenhouse gas emissions to half that of a traditional power plant and eliminating the need for transmission and distribution. Sure, the startup is likely coming out of the gates with a stationary power plant for large energy users. But the potential is far more tantalizing. The idea of locating these in individual homes to generate electricity for the home and grid - and potentially to create hydrogen for one's car at the same time - offers up a vision of a truly distributed energy economy, one that would change life and our relationship with energy as we know it. Yes, it's a long shot, but it's such a profoundly compelling one that Bloom will be on this list until we hear it won't hit home.