Robert Metcalfe, the guy who developed Ethernet, is now focused on clean, cheap power--and the world needs LOTS of it.
In this talk [real networks required] at MIT he discusses his concept of the Enernet and goes about mining the history--and his recollection, since he "was there"--of the Internet for lenses on how to view our current energy crisis.
His main thrust is that you can't do clean, or green, without cheap. The current trends, cleantech and green, miss the target:
- Cleantech--omits the need for "cheap"--no permanent solution works if it is not affordable.
- Green--is too anti-corporate, anti-global, anti-everything. This Luddite tendency will backfire, because the solution is has never been to regress.
"The climate change problem is going to get solved really quickly...But once we have solved that, we are still left with an energy problem"
Political expediency results in answers like corn based ethanol--bad feedstock made into a bad fuel. So Washington is not the answer.
"Spend less time telling us there are no silver bullets, and more time finding the damn silver bullets"
His answers have a lot to do with distributed generation, a (much) smarter grid, and welcoming the unexpected. Thus informed, I went on a search at Intersolar for silver bullets. Here is what I found:
Direct purification of metallurgical silicon to "upgraded metallurgical grade silicon or UMG Si" --BP, Elkem, Q-Cells, Dow Corning. Crystalline silicon cells much cheaper--much sooner. Warranties still an issue as degradation rates are not fully understood. 2008 production sold out. Ramping from 1200T in 2007 to 10,000T in 2009. Potential for silicon costs to go from $4.50/W [current spot] to $0.30/W [UMG Si at scale]--in under three years.
CPV--Concentrating Photovoltaics. The main players here are Concentrix, Solfocus, Greenvolts. The big advantage CPV has is that it performance degrades less with increased temperatures than flat plate PV does, the tricky part is the harvesting--you have to be pointing directly at the sun or you harvest nothing. Tracking is the killer app here.
cSi modules designed for high humidity environments--think HI, FLA, the Caribbean. EVA, the gel the cells sit in, loves moisture, this approach uses an inert gas and vacuum instead. Another harvesting technique.
And my favorite magic bullet wasn't even at Intersolar, since they are targeting the California market first.
...on my next project. I met with Ertex Solar when I was in Freiburg in June about their building integrated photovoltaic product. Glass--glass modules with architectural grade solar cells from Sunways--they call it PV Glass. The interstitial LED's were a little over the top, but the modules were beautiful. 
