A British company is poised to construct the world's first floating wind turbine, in a move that could herald a new generation of cheaper, less problematic wind energy.

Blue H, a firm registered in the UK but based in Holland, aims to anchor its prototype device 12 miles off the coast of southern Italy later this month.

The company is one of several racing to build commercial-scale floating wind turbines that sit in deep water far from land. These turbines benefit from more powerful winds and avoid many of the issues that afflict existing wind farms.

Neal Bastick, head of Blue H, said the Italian prototype would be "virtually invisible" from the shore, and that the company plans to build a full scale floating 90 megawatt wind farm in the region. Blue H also wants to build them off Scotland and the northeast US.

Bastick said the floating windmills would be more economic to install than existing offshore turbines, which sit on fixed foundations in the seabed. They could minimise problems with planning, as well as having less impact on shipping, military radar and coastal seabird populations. Electricity would be sent ashore using undersea cables.

The Blue H prototype will float a turbine platform on the sea surface and fix it in position using strong chains linked to heavy weights on the sea bed. Changing the length of the chains could allow the turbine to operate in water depths between 50m and 300m, enough to take it far out into the deep ocean.

The Blue H prototype turbine platform was launched in December 2007 and needs to be towed out to sea and connected to its seabed counterweight. Bastick said: "Within a few years I would very much like to be placing these off Britain."