The latest figures show that wind power usage is growing in the USA. There is over 18.2 GW of capacity in advanced development or directly in construction, according to a report produced by the American Wind Energy Association.

This is a significant amount of fresh capacity and actually equates to nearly a quarter of all existing current installed capacity, as well as representing more than the total combined existing capacity in place nine years ago. 

There are various reasons for the renewable technology's growth. The first is that Congress is now supporting wind power more through its tax credit system. Although the payments are being reduced by 20pc next year and then downwards on a sliding scale before being cut out completely by 2019, developers have been able to make longer-term plans without fearing annual and short-notice changes to the credit system. This provides investors with confidence and the right environment for new projects to go ahead.

Another key factor has been growing public support for this type of green energy. Polls show that consumers are now increasingly keen to see a greater use of wind energy and are keener to see a greater move towards renewable types of energy and away from fossil fuels.

It is interesting to note too that state policies have become more welcoming towards wind power as part of their renewable portfolio standards. Many states have now increased their renewable targets to at least 50pc. Other states are now looking at their own policies and considering upward revisions to targets.

The state currently leading away is Texas, which has 300pc more installed capacity than the next leading state. However, both Iowa and California do have a higher density of wind turbines overall. The signs are looking good for US wind power.