There's solar, true, and battery advances (like the one recently announced from MIT regarding lithium ion batteries, I believe), and several other viable choices. But what we really need is something that generates much more energy than those sources provide over a given course of time.
Fusion energy is, obviously, at least possible (unlike silly ideas like "zero-point energy"). The radiation from one great big obvious example of fusion energy silently crashes down upon our world every moment of every day. That form of fusion reaction, however, is caused by gravity and enormous heat and pressure, and occurs in an environment we don't (yet!) know how to replicate.
One of the people responsible for our nation's efforts toward fusion power thus far was Assistant Director Robert Bussard of the Controlled Thermonuclear Reactor Division in what was at the time known as the Atomic Energy Commission. He and Director Robert Hirsch founded the mainline US fusion effort, known as the Tokamak.
He also, more recently, made something else.
The Polywell reactor is a continuation of his research in this area. Briefly and oversimplified, the Polywell is, if Bussard's power output and power gain scaling laws are correct, the proverbial "magic bullet". A success with this form of reactor represents a fundamental change in human history and the definitive end of the petroleum era. If the Polywell design works as advertised, we will have cheap, relatively clean, nearly limitless energy- and I am not in any way engaging in hyperbole by stating it so baldly.
Meet WB-6 of this family of reactors:
Briefly and oversimplified (hope I get the concept right, as it's a bit complicated), the reactor creates an electrically charged potential well in the core of the device using magnetic fields. The coils (each one, individually) produce an electromagnetic field around themselves; these fields push against each other in such a way that the open "cusps" where the fields don't touch get squeezed shut (this is a scaled-up version of two small magnets meeting at points of equal polarity- N-N or S-S).
Here's an illustration of the reaction:
Boron-11 ions are fired into the core of the reactor; occasionally electrons circulate along the field lines. As the cusps become more and more closed, fewer and fewer electrons escape to recirculate. Additionally, more and more ions get fired into the core; you can see a simulation of that in
this video. Eventually, they begin to fuse, releasing energy, then they actually split, releasing more. I believe helium is the "exhaust".
There is enough boron on the Earth to supply such reactors with fuel for several thousand years. I do believe it may actually be orders of magnitude higher than that.
Bussard, at the time of his death, was convinced this would work. Given he's certainly no kook, I'm willing to at least fully fund a Polywell yay-or-nay program with my tax dollars. Apparently, the US Navy shares some of that optimism- they've been bankrolling the research thus far.
You can learn about the lab doing the research
here, the Polywell concept itself at
the Polywell Wiki page, and discuss it at
talk-polywell.org. I should add that the lab's director and others working on the project, some of whom worked with Dr. Bussard, are known to post on that last.
You can also find a wealth of information
here.
Here's to hoping Bussard was right about the scaling laws of this thing. If he was, and we build it right, our energy concerns will be a thing of the past, in one fell swoop.