A floating wind turbine that its makers claim could significantly boost the renewable energy sector was officially launched at a trade show in the German capital on Wednesday.

Dutch company Blue H Technologies said its invention, which adapts technology used in offshore oil rigs, was a world first.

It will soon go into operation off the coast of Puglia in southern Italy.

Unlike normal offshore wind turbines it does not need to be anchored to the seabed and can be used in waters deeper than 50 metres (164 feet), depths at which installation costs for fixed turbines become prohibitive.

The German government on Wednesday approved a major package of measures to fight climate change, including a target to make renewable energy from sources such as wind contribute between 25 and 30 percent of the country's energy needs by 2020, compared to the current level of 12 percent."