A couple of years ago I went to the open day of an energy generation equipment company:
rem Engineering
They have a wind turbine (if you use the M25 near Watford, you'll see it alongside the motorway).
I was impressed when one of the engineers stated that when the turbine comes to the end of its life, they can clear the site and a month later you wouldn't know it had been there. I know we're talking different levels of energy production, but I found it an interesting contrast to the years it takes to decommission a nuclear power station.
Jim