I know one thing that will be renewable every 20 years. The electricity generators inside. The salt air will degrade them quickly. Other parts too. Salt air being so corrosive.
This article says Europe has lots of offshore wind farms. Some young Americans are being sent to Denmark to get instruction on offshore wind farms and their machinery. There are community colleges in New England doing the same.
That is certainly true. I was in the Netherlands near the ocean a few years ago, and the horizon was blade-to-blade windmills.
Ever hear of a ship? Like these turbines, they’re designed to operate reliably in saltwater environments.
Offshore wind is great because the wind resource is strong, no farmland is lost, and since population is high along the coast the energy can be more economically delivered to users than when new costly transmission lines are required.
It also locates turbines in the “backyard” of liberal coastal city dwellers, making them aware of the tradeoffs involved with any form of power veneration facility. Every form of generation has pros and cons.