It was probably mining industry promotion. This report from Navigant Research, prepared on behalf of the Copper Development Association, contains both statistic

It was probably mining industry promotion. This report from Navigant Research, prepared on behalf of the Copper Development Association, contains both statistics and copper industry scheming regarding copper use in wind power: https://www.copper.org/publications/pub_list/pdf/a6198-na-wind-energy-analysis.pdf https://www.copper.org/publications/pub_list/pdf/a6198-na-wi... Most uses of copper in wind power can be substituted by aluminum when copper prices rise. Speaking on behalf of copper producers who want to impede substitution, the report says: Substitution by aluminum can be addressed with proactive promotion based on copper’s known benefits of higher energy efficiency (reduction of energy losses) and assurance of long‐term reliability. Aluminum is vulnerable here due to its lower strength, relaxation behavior and corrosion resistance. The downstream technical and economic risks associated with “value engineering” copper out of critical components are unknown. And, because the costs or repair, maintenance and downtime are known to be high in wind‐energy plants, copper promotion based on reducing life‐cycle costs through improved reliability and efficiency should be a worthwhile undertaking. Institutional promotion through the establishment of prudent codes, standards and recommended practices is also recommended. It's a mixture of highlighting legitimate engineering concerns, raising FUD about failure to address those concerns, and trying to get copper specifically entrenched in codes and standards so that aluminum will not be allowed to compete with copper. For answering the specific question of how much copper current wind power uses, see table 2-1. There's a lot of variation. The project built with 2.1 MW turbines from Suzlon had a copper intensity of 6.8 tonnes (14,900 pounds) per megawatt, while the project with 3.0 MW turbines from Vestas took only 2.5 tonnes (5600 lbs) per megawatt. Mass of copper per turbine is a poor metric because turbines come in various generating capacities.