Son Of Cold Fusion  

WorldChanging has a new report on sonofusion [pdf] (acoustic inertial confinement fusion), which is showing some promise as a possible (and practical) source of fusion based energy. It may just be a repeat of the disappointing experience with cold fusion - but you never know - worth keeping an eye on.

In Sonofusion (2004), we talked about Purdue physicists demonstrating thermonuclear fusion takes place in tiny bubbles in liquids hit by a pulse of neutrons and ongoing acoustic oscillation (i.e., sound); In Son of Sonofusion (2005), we talked about researchers at the University of Illinois Urbana-Champaign confirming aspects of the research, including the extremely high temperatures found in the collapsing bubbles (we're talking much hotter than the surface of the Sun). Now sonofusion returns, hotter and more powerful than ever...

If sonofusion works -- and we're probably still another couple of years from having solid confirmation -- it will take a decade or two at least before we could see any real world applications from it. It's not going to save us from having to do the hard work of moving away from fossil fuels. But another decade or two would mean it would be starting to come online in the early part of the 2020s, just when the conversion from gasoline and coal will start to really hit high gear -- an ideal moment, then, for another clean source of power to step onto the stage.

By 2050, we could be living in a world powered by wind, the Sun, and stars in a jar.

Solar photovoltaic generation of electricity has a big problem: with currently-available technology, it's not terribly efficient. I mean that literally; the "solar constant" is ~1.35 kilowatts of power per square meter, but most off-the-shelf solar panels can only convert about 20-30% of that to electricity. Improvement is clearly possible, and some researchers have figured out ways to boost that efficiency to 50% or more (although some promising developments in flexible, polymer-based photovoltaics are far worse, with only 5-15% efficiency). One of the more interesting approaches involves using selenium "nanocrystals" to boost efficiency to up to 60%. Now researchers at the US Department of Energy's National Renewable Energy Laboratory have pushed that concept to a new potential efficiency peak.

By using lead sulfide as the nanocrystal -- or "quantum dot" -- material, the NREL team claims a potential efficiency of more than 65%. We've noted various worldchanging applications of quantum dots before (for infrared-sensitive polymer photovoltaics with ~30% efficiency, and for high-efficiency reversible thermoelectric materials), and it's clear that nanomaterial and nanofabrication research will be critical for making solar photovoltaic sufficiently efficient for widespread adoption.