Energy generated by wind grew a “record breaking” 28% in the US last year – believed to be the country’s “best year ever”.

More than 6,700 new wind turbines were installed in 2012 – equivalent to powering around 3.5 million homes – backed by $25 billion (£16.3bn) of private investment, according to the American Wind Energy Association (AWEA).

Overall, America ended the year with 45,100 turbines, producing enough electricity to power around 15.2 million households. Wind power added 42% of all new capacity to the grid last year, beating other sources of energy generation.

Rob Gramlich, AWEA’s Interim CEO said: “We had an incredibly productive year in 2012. It really showed what this industry could do and the impact we can have with a continued national commitment to renewable energy. We’re doing what Americans overwhelmingly say they want: making more clean, renewable energy and creating good jobs in US factories.”

The news comes the same week Portugal announced it generated 70% of energy from renewable sources in the first quarter of 2013.