For the global renewable energy transition to work, hundreds of thousands of steel wind towers, monopiles and nacelle’s need to be built. The good news is, the iron is there and currently relatively cheap.
Weight of a large offshore wind turbine:
Rule of thumb 5 MW offshore wind turbine steel requirements: 300 + 2200 + 400 = 2900 ton
One million 5 MW offshore wind turbines require 2.9 billion ton or 88% annual global steel production.
Total world electricity consumption was 19,504 TWh in 2013. [source]
Annual electricity production 5 MW offshore ind turbine: 15 million kWh or 15 GWh
In other words: with 1.3 million offshore 5 MW wind turbines you have your global 2013 electricity consumption covered, if you ignore for a moment aspects like storage. And this time entirely fossil free, which was the purpose of the operation. But this ‘back-of-an-envelope’ exercise should give you an idea of the scale of the challenge.
Offshore wind turbine monopile production from steel plate.