Alternative energy watchers are all too aware of the polysilicon shortage on solar pv. But here's a similar angle that plays in the wind industry that we don't hear much about - fibers, the feedstock for turbine blades. And Vestas, the world's no. 1 wind turbine is taking action by closing a long-term supply deal with Zoltek.

Zoltek expects to provide Vestas with over $300 million of carbon fiber and carbon fiber materials over the first five years of the agreement, for the manufacture of rotor blades for wind turbine generators. Zoltek also anticipates expanding nameplate carbon fiber capacity from 2,800 metric tons in 2005 to 10,800 metric tons by early 2008.

There is a professional difference of opinion over the merits of glass fiber or carbon fibers for wind turbine blades - see this detailed anonymous article which disparages Zoltek (not least because back in April, he was shorting it) here. Zoltek is obviously in the carbon fiber camp and supplies Gamesa as well as Vestas. On the other side exist LM Glasfiber who supply - you guessed it - glass fiber turbine blades to Enercon, GE, Siemens, and Suzlon.

Broken turbine blades are worryingly frequent - perhaps this is ultimately why commercially available turbines cannot seem to surpass a size of 5 MW, because the blades are just not strong enough. If and when that does happen, maybe through nano-engineering, then 40 MW turbines become possible and the price of windpower will plummet like it did in the 1990s again.