Those heavy costs have killed some projects already.  

Image Title: Steel Windmill Towers--production emits CO2 
Image Info: The huge steel pilings for offshore windmills are typically 30 Ft diameter and up to 300 Ft long.  And the coal & coke oven furnaces to produce that steel emits about 5,000 tons of CO2, per a single piling.   A setback to the green targets. 

And very costly to build & install.   A project like Ocean City will need more than 300 such towers, and have over 900 fiberglass turbine blades.  And that's just the first phase of the project, with more planned in the future.    Rampant industrialization of our tourism and fishing environment.  Atrocious !!