As the cloud finally clears about five miles off the coast of Whitstable, a 440ft wind turbine slowly begins to rotate.

“When the water is flat and they turn slowly, I think they look majestic,” said Gunnar Groebler, head of business area wind at Vattenfall, the Swedish firm building another 15 electric windmills in the Kentish Flats wind farm.

Mr Groebler, who sits on the company’s board, is on his first visit to the extension work, having set off on a boat from Ramsgate harbour about an hour earlier.

Five turbines have been installed since the work began in May, with 15 set to be added to the 30 which have graced or polluted the view off the Kent coast for 10 years, depending on your personal opinion.

The £160 million extension will allow the wind farm to power another 35,000 homes a year, nearly doubling the 40,000 homes it already caters for on average, thanks to advancing technology and efficiency.

The company argues its work has a big impact on the county’s economy, with engineers and technicians staying in local hotels, while several boat operators from Whitstable, Herne Bay and Thanet carry them to the wind farm from the shore.

Boats leave from Thanet so the operation can continue around the clock, unhindered by tidal changes at Whitstable or Herne Bay.

It is hard not to be impressed by the giant structures on a closer look from our CTV, or crew transfer vehicle.

Although the water is relatively shallow at about 20ft, your mind is quickly frazzled as project director Matthew Green describes the complicated engineering efforts which go into installing the turbines and cabling which carries the electricity to shore.

The foundations are driven about 100ft into the seabed, with each windmill weighing about 600 tonnes.

Each propellor on the new turbines is marked with red dots, to make it easier for pilots to see them.

“It’s our primary project in the UK this year,” said Mr Green.

“It is quite difficult to install anything offshore when you take into account sea states, wind, corrosion and seabeds we don’t know much about. We also have heavy pieces of equipment we have to get here from Europe.

“We have been planning this for two years and actually it has gone very well.

“We’re more than halfway through construction and we’re a few weeks ahead of the programme.”

The project is expected to be finished and generating power by the end of November.

The work is likely to be the last off the Kent coast for a long time, with Vattenfall’s energies next focused on the “East Anglia zone”.

Mr Groebler added: “There is nothing in Kent we would be close to any decision on.”