The surprising connection between wind power and oil and natural gas.

Sustainability |  2 min. read

Once upon a time, wind power looked like this:

…and if you lived in the Netherlands in the 1600s, that worked pretty well.

Today’s wind power depends on the same breezes — but pretty much everything else has changed.

In Rembrandt’s day, windmills powered things like — mills, for grinding grain or sawing wood.  Wind power now, is a clean, sustainable source of energy for all of us:  generating enough electricity last year to power 26 million homes.

But that isn’t all that’s changed since the days of the Dutch master.  In his time, wood and cloth caught the wind (in the form of slats and sails).  Today’s “wind catchers” are giant blades, made of materials undreamt of in the 1600s:  like glass fiber in a polyester matrix, and carbon fiber embedded in an epoxy resin.

This isn’t the same polyester that’s in plastic bottles, though. If you move a couple atoms around a xylene molecule, then you get something called ortho-xylene. The polyester we’re most familiar with is made from para-xylene. Just that subtle change makes a different material with different properties.

The same is true with epoxies. One type that is found in many blades is a polymer made from a polycarbonate-epichlorohydrin molecule. Polycarbonate usually comes from acetone and phenol, both petrochemical derivatives, but the secret sauce for epoxies is the epichlorohydrin. Epichlorohydrin begins with propylene. In fact, propylene is also used in the cumene process to make the phenol and acetone. Propylene is cool stuff.

And you might be surprised to know that all these materials, essential for today’s wind turbines, ultimately begin with petroleum and natural gas.  Those chemicals make it possible to build blades that are strong AND lightweight AND big.

And you need those sort of aerospace materials to build modern turbine blades because these blades are really big.  The biggest one we know of is almost 300 FEET long (that’s almost a football field).  And even bigger is coming.

GE is building a new wind turbine with blades that are 351 FEET long.  At that size, they don’t even look like blades anymore…

(Photo from GE)

And three of those blades will be installed on a wind turbine that’s 850 feet high — or if you want, think of a 70-story building.  That high.  Which means, while the old Dutch windmill, with its wood slats or cloth sails, still looks as good as ever — today’s wind power depends on today’s materials.

Sources of energy like wind, clean and renewable (there’s always a wind blowing somewhere), are one important piece of our efforts to check global warming.  Today, there are more than 56,000 wind turbines spread around the country.  It’s almost tied with hydroelectric as the largest source of renewable generating capacity in the United States.

But producing all that new wind power, depends upon some tried and true ingredients — the petrochemicals, that make it possible to build this…