The company said the plans are part of strategy to invest $6 billion in its US operations. The remaining $2.1 billion will be spent on transmission projects.
Iberdrola said the level of investment was partly due to the US providing around $1 billion in grants to the company, as part of the government’s incentives programme.
However, earlier this year Iberdrola announced it was planning to reduce the amount of projects it developed in the US.
In March it said it planned to add 750MW worldwide in 2012, a reduction of 700MW on the expected 2011 figure of 1,450MW.
The falls will principally come in the Spain and the US. It said around 277MW would be developed in the US over 2012.