Offshore wind turbines are too expensive to dismantle, so will just be left to rot once they reach their use-by dates.
Fact:
Offshore wind turbines, like their counterparts on land, have a lifespan of 20 to 25 years. After that they can either be upgraded, repurposed, dismantled or left where they stand. A combination of all four options may be deemed appropriate for a wind farm.
Upgrading involves replacing the old blades and electronics, so the turbine has a new lease of life. Repurposing involves turning the base into a haven for wildlife (a breeding ground for seabirds, for example). Dismantling is not a technically difficult task and will soon be undertaken in Europe on a massive scale. The cheapest option, of course, is to dismantle the blades and the electronics, but leave the base where it stands. This is what was done with the offshore defences Britain built along its south coast during the Second World War. Many of these are still there today, slowly rotting away.
So, whatever option is chosen, it’s not a problem that will have to be faced till the second half of the century.
And while on this subject, we should not forget the estimated $60 billion cost of dismantling the offshore oil platforms that dot Australia’s coasts. This amount dwarfs any costs we might face in dismantling offshore wind farms.