Vestas will supply 55 V110-2MW turbines to the project site as part of a follow-on order from the two 200MW Los Vientos III and IV projects. The deal also includes three years servicing.
Windpower Monthly reported the deal earlier this month but details were not disclosed at the time.
Garland Power and Light, Greenville Electric Utility System and Bryan Texas Utilities have signed 25-year power purchase agreements with the project.
The project in Starr County, south Texas, is expected to be completed by the end of 2015, said Duke.
Vestas won a 400MW deal with Duke Energy last year to supply the V110-2MW to the Los Vientos cluster.