The most expensive and unefficient energy...

A two-megawatt windmill is made up of 260 tons of steel that required 300 tons or iron ore and 170 tons of coking coal, all mined, transported and produced by hydrocarbons.
It hold 700 gallons of oil and hydraulic fluid, and like car these need to be replaced every 9 months.

People might fall for the idea that we can merrily run on sunshine and breezes, alone, but with a few trillion dollars worth of mythical mega-batteries providing backup for a few minutes, it could spin until it falls apart over and over again and never generate as much energy as was invested in building it.