From Jenna Orkin

Bright Green Lies: How the Environmental Movement Lost Its Way

An excerpt from the book:

By mass, the main materials used in wind turbines are steel and concrete. Most of the steel is in the tower and the nacelle, and in the foundation in the form of structural reinforcements, often rebar. Concrete is generally used only in the foundation, but some wind turbines use concrete towers reinforced with steel instead of traditional steel towers. 

Blades are manufactured from wood and composite materials like fiberglass and carbon fiber, which are energy-intensive plastics made from petrochemicals. As one analysis notes, “Resins [used in wind turbine blades] begin with ethylene derived from light hydrocarbons, most commonly the products of naphtha cracking, liquefied petroleum gas, or the ethane in natural gas.... To get 2.5 TW of installed wind power by 2030, we would need an aggregate rotor mass of about 23 million metric tons, incorporating the equivalent of about 90 million metric tons of crude oil.”

Nacelles contain large amounts of copper and rare earth metals like neodymium (used for powerful magnets to increase reliability and performance). 

And of course, industrial wind-energy-harvesting facilities don’t exist in a vacuum; they require substations, transmission lines, control facilities, vehicles to haul maintenance teams, and so on.