The Spanish developer will install 101 Gamesa G97 2MW turbines at the project in southeast Texas near the city of Corpus Christi.
Construction at Baffin began in 2013. Once commissioned it will combine with the Peñascal I and II developments – each 202MW – to form Iberdrola's largest renewable project cluster.
Peñascal I and II use 168 Mitsubishi MHI 92 turbines, each with a unit capacity of 2.4MW.
Baffin is set to be online by the end of this year and the power produced will be bought by utility company Austin Energy.
Austin signed a 25-year power purchase agreement with Iberdrola in 2011.