An excellent article here "Silicon shortage strikes industry" by Tom Abate which sums up the solar industry's conundrum in a mere 500 words.

I'll try and do it in a lot less;

i) Polysilicon shortage creating prices of $75 - $80 per kilo compared to $32, 3 years ago
ii) This hampering industry growth from 67% in 2004 to 30% in 2005 and to an estimated 10% in 2006
iii) This affects the solar industry but has a negligible effect on chipmakers
iv) Only a few companies make silicon; Hemlock Semiconductor Corp. in Michigan; Wacker Chemie AG in Germany; Tokuyama, Mitsubishi Materials and Sumitomo Titanium of Japan; and REC Group (you could also add MEMC)
v) Long lead-times and expense of bringing new silicon plant online

What the industry needs is an online silicon marketplace with futures contracts pricing out 10 years - it seems to be a very illiquid material and the spectre of “. . . solar procurement people traveling around the world with suitcases full of cash” is not a scaleable situation for an industry that likes to think it has the brightest future of all.