The company’s chief executive, Olaf Pirlo, said: “Simple ideas are often the best, and repurposing existing buildings by turning them into giant windmills is much more cost effective than having to build a new turbine from scratch.
“The BT Tower is a good place to start because it’s basically the same shape as a wind turbine, but without the propellers. So we just need to stick some on the side of it.
“Other structures will be more challenging. For example the Blackpool Tower has sloping sides, so we will probably put a horizontal propeller on the top, like a helicopter. Hopefully it won’t take off when there is a strong wind!
“We are confident we can start work on the BT Tower Turbine by April 1 next year.”
The council is braced for strong opposition, however, as the BT Tower, formerly known as the Post Office Tower, is a Grade II listed building and is one of London’s most famous landmarks.
Completed in 1964, it was the tallest structure in London until 1980, when it was overtaken by the NatWest Tower.
The revolving restaurant was closed in 1980, and has not reopened since. In its heyday the restaurant would revolve once every 23 minutes, which engineers say would be quick enough to re-orientate a turbine fixed to the side of it so that it could respond to changing wind direction.